INFORMATION & COMMUNICATION

TECHNOLOGY SYSTEM MAINTENANCE

1st Semester

TRADE PRACTICAL

SECTOR: IT & ITES

DIRECTORATE GENERAL OF TRAINING

MINISTRY OF SKILL DEVELOPMENT & ENTREPRENEURSHIP
GOVERNMENT OF INDIA

NATIONAL INSTRUCTIONAL
MEDIA INSTITUTE, CHENNAI
Post Box No. 3142, CTI Campus, Guindy, Chennai - 600 032
Sector : IT & ITES
Duration : 2 - Years
Trade : Information & Communication Technology System Maintenance -
Trade Practical

Copyright © 2014 National Instructional Media Institute, Chennai

First Edition : November 2014, Copies : 1,000
First Reprint : January2016, Copies : 1,000
Second Reprint : May 2017, Copies : 2,000

Rs.230/-

All rights reserved.

No part of this publication can be reproduced or transmitted in any form or by any means, electronic or mechanical, including
photocopy, recording or any information storage and retrieval system, without permission in writing from the National
Instructional Media Institute, Chennai.

Published by:
NATIONAL INSTRUCTIONAL MEDIA INSTITUTE
P. B. No.3142, CTI Campus, Guindy Industrial Estate,
Guindy, Chennai - 600 032.
Phone: 044 - 2250 0248, 2250 0657, 2250 2421
Fax : 91 - 44 - 2250 0791
email : nimi_bsnl@dataone.in
Website: www.nimi.gov.in
(ii)
 FOREWORD

The National Instructional Media Institute (NIMI) is an autonomous body under the Directorate General of
Employment and Training (DGE&T) Ministry of Labour and Employment has been developing, producing
and disseminating Instructional Media Packages (IMPs are extensively used in the Industrial Training
Institutes/Training centres in Industries to impart practical training and develop work-skills for the trainees
and the trainers

The Ministry of Labour & Employment constituted Mentor Councils (MCs) to revampcourses run / to be
run under National Council of Vocational Training (NCVT) in 25 sectors. The MCs have representatives
from thought leaders among various stakeholders viz. one of the top ten industries in the sector innovative
entrepreneurs who have proved to be game-changers, academic/professional institutions (IITs etc.), experts
from field institutes of DGE &T, champion ITIs for each of the sectors and experts in delivering education
and training through modern methods like through use of IT, distance education etc. The technical support
to the MCs is provided by Central Staff Training and Research Institute (CSTARI), Kolkata and National
Instructional Media Institute (NIMI), Chennai. Some of the MCs are also supported by sector-wise Core
Groups which were created internally in the Ministry (in 11 sectors).

A Steering Committee to provide overall coordination and guidance to Mentor Councils has also been
constituted and has representation from the MCs, Chair positions to be endowed by the Ministry, trade
unions, and experts on distance education and training. The MCs are mandated to work towards revamping/
suggesting new courses, improving assessment systems, overall learning etc. for subjects under the
purview of the NCVT.

Accordingly NIMI with the support and assistance of MC has developed Information & Communication
Technology System Maintenance Trade Practical 1st Semester in IT & ITES sector to enhance the
employability of ITI trainees across the country and also to meet the industry requirement.

I have no doubt that the trainees and trainers of ITIs & Training centres in industries will derive maximum
benefit from these books and that NIMI’s effort will go a long way in improvement of Vocational Training.

I complement Director, Mentor Council members, Media Development Committee (MDC) members and
staff of NIMI for their dedicated and invaluable contribution in bringing out this publication.

ALOK KUMAR, I.A.S.,

Director General of Employment &
Training/ Joint Secretary
Ministry of Labour and Employment
Government of India

New Delhi - 110 001

(iii)
 PREFACE
This National Instructional Media Institute (NIMI) was set up at Chennai by the Directorate General
of Employment and Training (DGE&T) Ministry of Labour and Employment, Government of India
with technical assistance from the Govt. of the Federal Republic of Germany. The prime objective
of this institute is to develop and disseminate instructional materials for various trades as per
the prescribed syllabi under the Craftsmen and Apprenticeship Training Schemes.
The instructional materials are developed and produced in the form of Instructional Media
Packages (IMPs). An IMP consists of Trade Theory book, Trade Practical book, Test and
Assignment book, Instructor guide, Wall Charts and Transparencies.
Hon'ble Union Minister of Finance during the budget speech 2014-2015 mentioned about
developing Skill India and made the following announcement
"A national multi-skill programme called Skill India is proposed to be launched. It would skill the
youth with an emphasis on employability and entrepreneur skills. It will also provide training and
support for traditional professions like welders, carpenters, cobblers, masons, blacksmiths,
weavers etc. Convergence of various schemes to attain this objective is also proposed."
The Ministry of Labour & Employment constituted Mentor Councils (MCs) to revamp courses
run / to be run under National Council of Vocational Training (NCVT) in 25 sectors which will give
a sustained skill based employability to the ITI trainees as the main objective of Vocational
training. The ultimate approach of NIMI is to prepare the validated IMPs based on the exercises
to be done during the course of study. As the skill development is progressive the theoretical
content on a particular topic is limited to the requirement in every stage. Hence the reader will
find a topic spread over a number of units. The test and assignment will enable the instructor to
give assignments and evaluate the performance of a trainee. If a trainee possesses the same it
helps the trainee to do assignment on his own and also to evaluate himself. The wall charts and
transparencies are unique, as they not only help the instructor to effectively present a topic but
also helps the trainees to grasp the technical topic quickly. The instructor guide enables the
instructor to plan his schedule of instruction, plan the raw material requirement ,
Thus the availability of a complete Instructional Media Package in an institute helps the trainer
and management to impart an effective training. Hence it is strongly recommended that the
Training Institutes/Establishments should provide at least one IMP per unit. This will be small,
one time investment but the benefits will be long lasting.
The Information & Communication Technology System Maintenance Trade Practical 1st
Semester in IT & ITES sector is one of the book develop by the core group members of the
Mentor Councils (MCs). The 1st semester book includes Module 1 - General & Electrical
Safety, Module 2 - Basic Electrical, Module 3 - Basic Electronics,
Module 4 - Digital Electronics, Module 5 - Drives, Relays & Sensors
The ICTSM trade Practical 1st semester is the outcome of the collective efforts of Members
of Mentor Council which includes academic/professional institutions (IITs etc.) , experts from
field institutes of DGE&T, champion ITIs for each of the sectors, and also Media Development
Committee (MDC) members and staff of NIMI.
NIMI wishes that the above material (Trade Practical & Trade Theory) will fulfil to satisfy the long
needs of the Trainees and Instructor and helps the trainees for their employability in vocational
training.
NIMI would like to take this opportunity to convey sincere thanks to all the Mentor Council members and
Media Development Committee (MDC) members.
A. MAHENDIRAN
Chennai - 600 032 Director, NIMI.

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 ACKNOWLEDGEMENT

National Instructional Media Institute (NIMI) sincerely acknowledges with thanks for the co-operation and
contribution extended by the following Media Developers and their sponsoring organisation to bring out this IMP
(Trade Theory) for the trade of ICTSM under the IT & ITES Sector for Craftsman Training Scheme. This Book
is prepared as per Revised Syllabus.

MEDIA DEVELOPMENT COMMITTEE MEMBERS

Dr. Sanjeev Kumar Gupta - Additional Director (IT),

NIELIT, Deity, MCIT, New Delhi.
Chairman, Mentor council.
Shri. Naresh Chandra - Joint Director of Training ,
DGE&T, New Delhi
Mentor, Mentor council.
Dr. M. Jayaprakasan, - Deputy Director of Training,
ATI, Chennai
Team Leader, Mentor council.
Shri. St. Altaf Hossain - Training Officer,
ATI, Howrah.
Member, Mentor council.
Shri. P.T. Noushad - Assistant Training Officer,
Govt. ITI (W), Coimbatore.
Member, Mentor council.
Shri. Indu Jaisal - Senior Technical Leader
MDC Member-NIMI.
Member, Mentor council.
Shri. N. Sundararajan - Training Officer,
NIMI, Chennai - 32
Co-ordinator, NIMI, Chennai.
Shri. V. Gopalakrishnan - Training Officer,
NIMI, Chennai - 32
Co-ordinator, NIMI, Chennai.

NIMI records its appreciation of the Data Entry, CAD, DTP operators for their excellent and devoted services in the
process of development of this instructional material.

NIMI also acknowledges with thanks, the invaluable efforts rendered by all other staff who have contributed for the
development of this Instructional material.

NIMI is also grateful to all others who have directly or indirectly helped in developing this IMP.

(v)
 INTRODUCTION
TRADE PRACTICAL

This manual of trade practical consists of a series of practical exercises and Lab assignments to be
completed by the trainees during the first semester of the Information & Communication Technology System
Maintenance (ICTSM) course. These exercises are designed to ensure that all the skills in the prescribed
syllabus are covered. The manual is divided into Five modules. The distribution of time for the practical in the
Five modules is givenbelow.

Module 1 General & Electrical Safety 25 Hrs.

Module 2 Basic Electrical 160 Hrs
Module 3 Basic Electronics 180 Hrs
Module 4 Digital Electronics 100 Hrs
Module 5 Drives, Relays & Sensors 60 Hrs
Total 525 Hrs

While developing the practical manual, effort was made to prepare the exercises to be easily

understood and carried out by trainees whose level is below average. However the development team accepts
that there is a scope for further improvement, NIMI looks forward to the suggestions from the experienced
training faculty to improve the material.

TRADE THEORY

The manual of trade theory consists of theoretical information for the First Semester course of the ICTSM
Trade.The contents are sequenced according to the practical exercises contained in the manual on Trade
practical.Attempt has been made to relate the theortical aspects with the skill covered in each exercise to
the extentpossible. This co-relation is maintained to help the trainees to develop the perceptional capabilities
forperforming the skills.

The Trade Theory has to be taught and learnt along with the corresponding exercise contained in the manualon
trade practical. The indications about the corresponding practical exercise are given in every sheet of
thismanual.

It will be preferable to teach/learn the trade theory connected to each exercise atleast one class before
performing the related skills in the lab. The trade theory is to be treated as an integrated part of each exercise.

The material is not the for the purpose of self learning and should be considered as supplementary to class
room instruction.

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 CONTENTS

Exercise No. Title of the Exercise Page No.

Module 1 : General & Electrical Safety

1.1.01 Identify safety signs and practice artificial respiration 1

1.1.02 Practice electrical safety & extinguishing of fire 3

Module 2 : Basic Electrical

1.2.01 Identify fuses & switches 6

1.2.02 Identify the meter types and measuring range 8

1.2.03 Practice on analog multimeter 13

1.2.04 Practice in using digital multimeter 20

1.2.05 Skinning, Tinning and Soldering wires 25

1.2.06 Desoldering wires from lug board and soldering practice 31

1.2.07 Identify, find value and measure resistance of fixed value resistors 33

1.2.08 Verfication of Ohm’s law 40

1.2.09 Verification of Kirchhoff’s current and voltage law 44

1.2.10 Measure power directly and indirectly 49

1.2.11 Identification and testing of special type of resistors 51

1.2.12 Measuring AC and DC wave parameters using CRO 53

1.2.13 Identify, find the value of inductors & measure inductive reactance 55

1.2.14 Determine mutual inductance (M) and coefficient of coupling (k) of coils 58

1.2.15 Find transformation ratio and conduct OC, SC test for transformer 60

1.2.16 Testing transformers voltage regulation and efficiency 64

1.2.17 Winding low VA rating mains transformer 66

1.2.18 Identify and test fixed value capacitors 69

1.2.19 Measure C, find Xc and Z of a RC circuit 74

1.2.20 Characteristics of series & parallel resonance circuit 78

1.2.21 Identify and measure voltage of dry cells/battery 83

1.2.22 Form a DC source 6V/500 mA using 1.5V cells 87

1.2.23 Routine maintenance of Lead-acid battery 91

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Exercise No. Title of the Exercise Page No.

Module 3 : Basic Electronics

1.3.01 Identification of rectifier diodes, its specifications and testing 95

1.3.02 Construct and test half-wave and full-wave rectifiers using diodes 101

1.3.03 Construct and test a bridge rectifier 105

1.3.04 Construct & test a rectifier circuit with capacitor filter 107

1.3.05 Identification and testing zener diodes 112

1.3.06 To construct a zener regulated power supply 115

1.3.07 Identify, find specifications and quick test transistors 117

1.3.08 Find & Plot static characteristics of a transistor amplifier 122

1.3.09 Find voltage gain, Power ganin, Input/Output impedance and phase
relationship of a common emitter amplifier 127

1.3.10 Construct and test a common collector or emitter follower amplifier 131

1.3.11 Construct and test a common base amplifier 135

1.3.12 Testing of JFET, JFET amplifiers 138

1.3.13 Construct and test a relaxation oscillator using UJT 141

1.3.14 Identify and test SCR, TRIAC and DIAC 144

1.3.15 Construct and test crow bar protection circuits using SCR(s) 150

1.3.16 Construct and test a lamp dimmer/fan motor speed regulator

using TRIAC and DIAC 153

1.3.17 Construct and test series voltage regulator circuit 155

1.3.18 Construct and test fixed and variable regulated power supply using ICs 159

1.3.19 Identify the controls of an UPS and operate 166

1.3.20 Demonstration of the internal parts of a CRO 168

1.3.21 Measurements using oscilloscope 169

1.3.22 Use of controls in dual trace, dual beam and storage oscilloscope 170

1.3.23 Construct and test amplitude modulator/AM transmitter 171

1.3.24 Construct & test a crystal AM receiver 173

1.3.25 Construct & test a FM receiver 176

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Exercise No. Title of the Exercise Page No.

Module 4 : Digital Electronics

1.4.01 Identify and test digital IC(s) using IC tester 176

1.4.02 Construct and test NOT gate, logic probe and logic level indicator circuits 180

1.4.03 Construct and test OR, NOR gate and RS flip flop 185

1.4.04 Construct and test circuits of AND, NAND and EX-OR gates 189

1.4.05 Construct and test the circuits of R-S flip-flop and D flip flop using
NAND gate 194

1.4.06 Construct and test J-K flip-flop and counter 199

1.4.07 Construct and test an UP/DOWN decade counter using 74LS190 204

1.4.08 Construct and test a half adder and full adder circuits 206

1.4.09 Construct and test a half subtractor & full subtractor circuits 209

1.4.10 Construct and test multiplexer and demultiplexer circuits 211

1.4.11 Construct and test an analog to digital converter 214

1.4.12 Construct and test digital to analog (D/A) converter 216

1.4.13 Construct and test shift registers 218

Module 5 : Drives, Relays & Sensors

1.5.01 Identify & test types of gears, belts & drives 221

1.5.02 Identify different types of relays and sensors 223

1.5.03 Identify different types microprocessor chips 226

Appendix - C 230
Appendix - D 232

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IT & ITES
ICTSM - General & Electrical Safety Exercise 1.1.01

Identify safety signs and practice artificial respiration

Objectives: At the end of this exercise you shall be able to
• identify the different types of safety signs
• prepare safety signboards
• give artificial respiration using different methods.

Requirements

Tools/Equipments/Instruments • Rubber mat - 1 No.

• Rubber gloves - 1 No.
• Wall chart on safety signs
• Wall chart on artificial
respiration practice

PROCEDURE

TASK 1: Identification of safety signs

1 For the safety signs in column 1 of Table - 1 given at the 2 Get the work checked by your instructor.
end of this exercise, identify and record the different
types of signs and their meaning in columns 2 and 3.

TASK 2 : Artificial respiration

1 Make groups of 2 trainees each. One trainee shall act 4 Repeat the practice by changing the roles of the
as the victim and the other to practice giving artificial trainees.
respiration.
5 Record the method of artificial respiration practiced and
2 Ask your instructor for the method of artificial respiration difficulties faced, if any.
to be practiced by your group.
3 Follow the procedure given in Lesson 1.1.01 and practice
giving artificial respiration.

Record Sheet for Exercise 1.1.01

For TASK 2

1 Names of the persons in the group :

i)
ii)
2 Method of artificial respiration practiced :
3 Difficulties in practicing the method, if any :

(Trainee) (Instructor)

1
 Record sheet for Exercise 1.1.01
TABLE - 1
Sign Type Meaning Sign Type Meaning

(Trainee) (Instructor)
2 IT & ITES : ICTSM - Exercise 1.1.01
IT & ITES
ICTSM - General & Electrical Safety Exercise 1.1.02

Practice electrical safety & extinguishing of fire

Objectives: At the end of this exercise you shall be able to
• rescue and treat victims of electrical shock
• identify different types of fire extinguishers
• put out the fire using the fire extinguishers.

Requirements

Tools/Equipments/Instruments • Oil/Cotton waste water-filled

extinguisher (Common for CO2 or
• Rubber mat - 1 No.
CTC extinguisher 4 batches)
• Rubber gloves - 1 Set.
• Fire extinguishers - 2 in each type
• Scrap materials like wood/wire - as reqd.

PROCEDURE

TASK 1: Rescue and treat victims of electrical, shock

1 Participate in the demonstration conducted by your 3 Record the names of trainees in your group and the
insructor in rescuring and treating victims of electric different types of electric shock situations simulated for
shock. practice.
2 Make groups of two trainees simulating situations, with
one receiving the shock and the other rescuing and
treating the victims.

TASK 2 : Identify different types of the extinguishers

1 Identify and record the types of fire extinguishers 2 As instructed by your instructor, take part in the fire
available in your institute. Also record the type and fighting general type of fire and electrical fire.
class of fires in which these extinguishers can be use.
3 Record the activities carried out by you in fire-fighting.

TASK 3 : Put out fire using the fire extinguishers

1 Slect CO2 (Carbon di oxide) fire extinguisher. 4 Pull the safety pin from the handle (Pin located at the
top of the fire extinguisher) (Fig 3)
2 Locate and pickup, CO2 fire extinguisher. Click for its
expiry date.
3 Break the seal (Fig 2)

5 Aim the extinguisher nozzle or hose at the base of the

fire (this will remove the source of fuel fire) (Fig 4)

Keep your self low

3
 Fire extinguishers are manufactured for use
from the distance.

Caution

• While putting off fire, the fire may flare up

• Do not be panick
• If the fire doesn’t respond well after you
have used up the fire extinguisher move
away yourself away from the fire point.
• Do not attempt to put out a fire where it is
6 Squeeze the handle lever slowly to discharge the agent emitting toxic smoke leave it for the
(Fig 5) professionals.
• Remember that your life is more important
7 Sweep side to side approximately 15 cm over the fuel than property. So don’t place yourself or
fire until the fire is put off (Fig 5) others at risk.
In order to remember the simple operation of
the extinguisher. Remember P.A.S.S. This will
help you to use the fire extinguisher.
P for Pull
A for Aim
S for Squeeze
S for Sweep

4 IT & ITES : ICTSM - Exercise 1.1.02

 Record sheet for Exercise 1.1.02

TASK 1

1 Name of trainees in the group practicing rescue and treatment for victims of electric shock.

2 Type of electric shock situation simulated and rescue treatment practised.

1 Table

SI. No. Types of Fire Extinguisher Class Application

2 Write a few sentences about the activities performed by you as a member of the fire-flighting team.

IT & ITES : ICTSM - Exercise 1.1.02 5

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.01

Identify fuses & switches

Objectives: At the end of this exercise you shall be able to
• identify different types of fuses by their appearance
• check the condition of fuses
• identify different types of switches by their appearance
• check the condition of switches.

Requirements

Tools/Equipments/Instruments • SPST switch 6A/250V AC,

2.5A/24V DC - 1 No.
• Multimeter - 1 No.
• SPDT switch 15A/250V AC,
• Fuse catridge type - 1 No.
2.5A/24V DC - 1 No.
• Fuse fiber tube type - 1 No.
• DPST switch 10A/250V AC,
• Fuse ribbon type - 1 No.
7A/24V DC - 1 No.
• Thermal cutoff fuse - 1 No.
• DPDT switch 10A/250V AC,
• Blade type fuse - 1 No.
7A/24V DC - 1 No.
• Fuse knife blade cartridge type - 1 No.
• Tumbler switch 1pole, 20A/270V DC - 1 No.
• Copper fuse link - 1 No.
• Push button switch 0.5A/24V AC/DC - 1 No.
• Fuse plug type with ribbon fuse link - 1 No.
• Toggle switch SPST, SPDT
• Fuse holder clip type - 1 No.
center OFF, 6A/250V DC - 1 No.
• Fuse holder kit kat type - 1 No.
• Piano switch 6A/230V AC - 1 No.
• Post type holder - 1 No.

PROCEDURE

TASK 1 : Identify the type of fuses by their appearance & check defects

1 Take any one of the fuse from the given lot and compare 2 Repeat step 1 for the remaining given fuses.
its approximate physical appearance with the fuses
shown in chart 1 and identify the type name and record 3 Get your work checked by your instructor
it.

TASK 2 : Check the condition of fuse by using ohm meter

1 Check the physical condition of the given fuse one by 3 Connect the terminals multimeter to each ends of fuse
one and discard the defective fuse. and test the condition.
2 Connect the probes of ohm meter/multimeter terminals. 4 Repeat the steps for remaining fuses.
Set the meter to the continuity testing range.

TASK 3 : Identify & test switches

1 Identify given SPST switch by physical apperance & 3 Repeat above step for all given switches.
note down its specification.
Instructor should keep ready following types of
2 Set the multimeter in continuity & test continuity of
switches for demonstration.
switch by operating (ON/OFF mode) it.
4 Identify the specification of switch and tabulate the
results in Table 2.

6
 Table 1

SI. No. Type of switch No. of contacts Rating Resistance Condition

ON OFF Good Bad
1

10

Table 2

SI. No. Type of switch Rating Resistance Condition

Good/Bad
1

10

IT & ITES : ICTSM - Exercise 1.2.01 7

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.02

Identify the meter types and measuring range

Objectives: At the end of this exercise you shall be able to
• identify the type of instruments (AC/DC) and their function from the dial markings
• identify the type of instruments (AC/DC) from the markings on the terminal.

Requirements

Tools/Equipments/Instruments • Multimeter - 1 No.

• Voltmeter 0 - 300 V MC - 1 No. • Multi-range voltmeter MC 0-75, 150,
• Ammeter MI 0-15 A panel board type - 1 No. 300 & 600 V - 1 No.
• Ammeter 0 - 5A MC - 1 No. • Multi-range voltmeter MI 0-150, 300
• Ohmmeter-shunt and series type - 1 each. and 600 V - 1 No.

PROCEDURE
TASK 1: Identify the types of instruments (AC/DC) and their functions from the dial marking.

1 Identify the instruments shown in (Figs 1 & 2) for the

type DC, AC or both - with reference to Chart 1. Record
your response in Table 1.
2 Identify the functions of instruments by referring to the
symbol on the dial. (Figs 1 & 2)
Record the observation in Table 1.
3 Identify the instruments shown in (Fig 3 to 8), as a single
or multi-scale/ multi-range instruments and the func-
tions. Record your response in Table 2.

8
 TABLE 1

InstrumentSymbol Type AC/DC Function

TABLE 2

Instrument Range:single Scale single Function V

or multi-range or multi-scale or A or ohms

IT & ITES : ICTSM - Exercise 1.2.02 9

Instrument Range:single Scale single Function V
or multi-range or multi-scale or A or ohms

10 IT & ITES : ICTSM - Exercise 1.2.02

 Instrument Range:single Scale single Function V
or multi-range or multi-scale or A or ohms

4 Identify the working position, accuracy (error of indica-

tion), type and function of the instruments in ( Figs 1 &
2) and record in Table 3.

5 Further identify the given instruments from the labora-

tory and fill up the details in Table 3.

TABLE 3

Instrument Type Function Accuracy Working position

Symbol Description Symbol Description Symbol Description Symbol Description

Figure 1

Figure 2

Lab instrument

Lab instrument

Lab instrument

Lab instrument

The serial number of the instrument and other distinct marks should be entered under the ‘instrument’ column.

IT & ITES : ICTSM - Exercise 1.2.02 11

TASK 2: Identify the type of instrument (AC/DC) from the marking of the terminals.

1 Identify the connecting terminals of the instrument in

the given (Figs 9 to 11).

2 Note down the mark in the terminals shown in Figs 9 to

11 and record in Table 4.

If the terminals are marked (+) and (–) or any-

one of them is coloured red, the meter nor-
mally is a DC meter or MC meter.

If there is no terminal marking, then the meter

normally is an AC/DC or MI-meter.

3 Refer to (Figs 9, 10 & 11) and identify the type of

instrument, their function and record in Table 4.

4 Identify the given instruments from the lab and enter the
details in Table 4.

(The instrument serial number or other distinct marks

should be entered under Inst. No.)

TABLE 4

Sl.No. Inst. No. Polarity Function Type

1 Fig 9

2 Fig 10

3 Fig 11

10

12 IT & ITES : ICTSM - Exercise 1.2.02

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.03

Practice on analog multimeter

Objectives: At the end of this exercise you shall be able to
• select and connect proper coloured test prods in the multimeter
• select the right position of the function switch for the type of voltage or current being measured (AC/DC)
• set the multimeter to the right measuring range, using the selector switch
• connect the multimeter to the measuring object/circuit
• measure the voltage or current using the multi-scale in the dial
• make voltage and current measurements observing the necessary safety rules
• select the resistance range, set the zero ohm position and measure the resistance.

Requirements

Tools and Instruments Materials

• Multimeter with test prods - 1 No. • D.P.S.T knife switch 16A 250V - 1 No.
• Long nose pliers 150mm - 1 No. • Tag board - 3 Nos.
• Tweezer 150mm - 1 No. • Resistor 1/2 Watt 200, 680 ohms,
• Soldering iron 25 W,230V - 1 No. 1.5K,3.3K,4.7K and 330K - 1 No. each
• Nipper pliers 150mm - 1 No. • Resistor 27 ohms 5 W, 2K ohms
• Combination pliers 200mm - 1 No. 1 W, 6.8 ohms 20 W - 1 No. each
• Solder sucker - 1 No. • Resistor 15 ohms 10 W, 15K 1/2W
Equipment/Machines 150 ohms 2 W - each 2 Nos.
• Rosin cored solder 60/40 - 20 grams
• Auto-transformer having input • SPST knife switch 16A with
0-220V AC, and output 0-270V 5 A - 1 No. fuse arrangement - 2 Nos.
• Battery 12 V, 60 AH or variable - 1 No. • Crocodile clips 16 amps - 2 Nos.
power supply unit • Fuse wire 5 amps
0-30V/DC 2 amps 1 Amp - 200 mA Glass - as reqd.
Catridge with holder

PROCEDURE

TASK 1 : Measurement of D C voltage using a multimeter

1 Prepare the resistor board using tag board and resistors 2 Collect a multimeter.
as shown in Fig 1 and connect with the supply through
the fuse and SPST knife switch. Identify and investigate the use of the function
switch, range switch, dial marking and the
terminals before using the meter. However,
Fig 2 is for a particular make multimeter given
for your guidance. If you are using a multimeter
for the first time, it is always better to read the
instruction manual thoroughly atleast twice
before using the meter.

3 Set the function switch to DC position.

4 Set the range selector switch at the available higher
range of voltage in the multimeter.

If you are sure about the magnitude of the

voltage to be measured, then set the range
switch to the suitable range. Otherwise set the
multimeter range selector at a higher range.

13
5 Plug the black test lead in the common jack and the red
test lead in the positive jack.

Some multimeters are provided with separate

female jacks for various measurements. Check
and use proper jacks for D C.

6 Connect the multimeter to the resistance board as

shown in Fig 1.

Ascertain the supply polarity with respect to the

meter polarity.

7 Switch on the power supply.

8 Observe the pointer deflection of the meter.

If the needle deflects reverse, switch 'off' the

voltage source and interchange the testing
lead connections at the measuring points. Never
disconnect the testing leads at the measuring
instruments.

9 Observe the position of the pointer on the dial. If the

pointer deflects less than mid -scale, set the multimeter
range selector to the next lower range and so on, till you
get a reading just mid-scale or preferably beyond
mid-scale but within full scale.

Remember, if the percentage error is 3% for the

full scale deflection at the middle of the scale,
the error goes to 6% and for 1/4th scale deflection
the error shoots up to 12%. Hence it is advisable
to get the reading somewhere between the
SPECIAL TASK : Common procedure for voltage
centre of the scale to full scale to have a lower
and current measurements to read the
error in the measurement.
multi-scale dial
10 Observe the selected voltage range and read the scale
i Ascertain the setting of the function switch to
of the meter and record them in Table 1 against the
confirm whether the quantity being measured is AC
column 0-A.
or DC. (Refer to Fig 2).
11 Determine the multiplying factor and record it in Table
ii Ascertain the setting of the range switch to confirm
1.
whether the quantity being measured is voltage or
12 Determine the actual value and record it in Table 1. current and what is the suitable range.

TABLE 1
Electrician
DC voltage measurement
1st Year
Sl. Measuring Selected voltage Multiplication Measured Actual voltage
No. points range factor (MF) value (M.Value) M.Value x MF (volts)
1 O-A
2 O-B
3 O-C
4 O-D
5 O-E
6 O-F

14 IT & ITES : ICTSM - Exercise 1.2.03

 iii Check the dial marking for the following as shown in iv From the setting of the range switch value (Step ii)
Fig 3. and the range shown in the dial(Step iiic) determine
the multiplying factor.
a AC or DC scale as per setting of the function switch
v Ascertain the position of the pointer without parallax
b Voltage or current indication on scale as per setting error and read the number of divisions as shown by
of the range switch. the pointer on the scale.
c Range shown in dial and divisions as per setting of vi Read the value, following the instructions given
the range switch. below.

Sometimes the same scale will be used for two If the pointer shows a reading within the scale,
or more measurements. Refer to Fig 3. 10V and the actual quantity of measurement can be
1000V are having the same scale. 50V and 500V calculated by considering the number of
are having the same scale. 10 mA and 100 mA divisions shown by the pointer on the scale,
are having the same scale. The quantity being setting of the range selector switch and the
measured is decided by the setting of the range total number of full scale divisions as indicated
switch. in that range scale.

The formula and the example given below will clarify this statement

Formula

Actual quantity = Multiplying factor x No. of divisions shown by the pointer

Setting of Range selector switch

Setting of range selector switch =
Total divisions on the scale

Setting of Range selector switch x No. of divisions shown by the pointer

Actual quantity =
Total divisions on the scale
Example - ( Figs 2 & 3)
1 Function switch -- DC position
2 Range switch position voltage or current -- voltage
3 Range switch -- 2.5 V position
4 Range shown in dial scale -- 250 V

Setting of Range selector switch (step 3) 2.5 1

5 Multiplying factor = = =
Total divisions on the scale (step 4) 250 100
6 Read the number of divisions shown by the pointer (Fig 3) – 125.
7 Actual quantity = Multiplying factor x No. of divisions shown by the pointer

= (1/100)x125 = 1.25 volts.

13 Switch 'off ' the supply. 17 Follow the same procedure given in steps 13 to 16 for
14 Change the range selector switch to a suitable (next measuring voltages between the points O-C, O-D, O-E
higher) range. and O-F.

15 Connect the multimeter between the points O and B. 18 Show the readings to your instructor and get his
approval.
16 Read the voltage between the points O and B and record
in Table 1.

TASK 2: Measurement of AC voltage using a multimeter

1 Use the resistance board of Task 1 and connect the

Remember that the multimeter function switch
same with AC supply as in Fig 4.
should be set to match the type of source to be
2 Set the function switch to AC position. measured

IT & ITES : ICTSM - Exercise 1.2.03 15

3 Set the range selector at the highest range of AC
voltage.
4 Make connections to the multimeter and resistance
board as shown in Fig 4.

The polarity of the test leads is immaterial in AC

measurement. However make it a practice to
connect the common test prod (black) to the
near ground terminal and positive lead (red) to
the higher voltage terminal of the circuit.

5 Repeat the working steps 9 to 18 as in Task 1 and enter

the values in Table 2.

TABLE 2
AC voltage measurement

Sl. Measuring Selected voltage Multiplication Measured Actual voltage

No. points range factor (M F) value (M.Value) M.Value x MF (volts)

1 O-A
2 O-B
3 O-C
4 O-D
5 O-E
6 O-F

TASK 3: Measurement of direct current using a multimeter

1 Prepare the resistance board using the tag board with 6 Plug the ammeter between plug 1 and plug 2 in the
resistors as shown in the circuit. (Fig 5) circuit A to read the current in circuit A as shown in
2 Form the circuit with 12V DC supply as shown in Fig 5. Fig 5.

Before using the multimeter to measure the Remember an ammeter should always be
current, find out the DC ranges of the currents connected in series with the circuit.
to be measured and ensure that the circuit
current is well within the available range of 7 Close the circuit switch for a moment and watch the
meter. deflection of the pointer.
8 Open the switch immediately, if the pointer reaches
3 Set the function switch to the DC position. beyond the full scale deflection, reset the meter for a
4 Turn the selector switch to the highest range of current, higher range.
if the current to be measured is not known to you; 9 Switch off the supply, if the pointer shows a negative
otherwise set to the known range. direction of deflection and interchange the test leads at
5 Connect the test leads to the terminals of the multimeter the measuring points.
as indicated on the terminals or as shown in the manual 10 If the pointer shows the reading within the scale, keep
of that particular multimeter. the switch on, read the scale measurement and record
the readings in Table 3.
Now the multimeter is functioning as a DC
ammeter.

16 IT & ITES : ICTSM - Exercise 1.2.03

 If the needle deflects less than half the scale,
set the multimeter range selector to the next
lower range and so on, till you get a reading
just half scale or preferably beyond half scale
but within full scale.

11 Observe the selected current range and determine the

multiplying factor and record them in Table 3.
12 Compute the actual value and enter it in Table 3.
13 Switch off the power supply.
14 Change the ammeter connections to read the current in
the B circuit as shown in Fig 5.
15 Switch on the power supply and turn the selector switch
to a suitable range so that the pointer reads within half 16 Read the scale of the multimeter and record in Table 3.
and full scale positions. 17 Repeat the procedural steps 11 and 12.
18 Repeat the above procedures for measuring the current
in the circuits C,D,E and F as in Fig 5.

TABLE 3
DC current measurement

Sl. Measuring Selected current Multiplication Measured Actual current

No. points range factor (M.F) value (M.Value) M.Value x MF (Amps)
1 O-A
2 O-B
3 O-C
4 O-D
5 O-E
6 O-F

TASK 4 : Measurement of alternating current using a multimeter

Only certain types of multimeters will have the

facility of measuring alternating current. Check
whether the multimeter supplied to you has
this facility. If it does not have the facility, do not
attempt to measure alternating current by your
multimeter. If it has the facility, proceed as
stated below.

1 Prepare the resistance board using a tag board and

resistors as shown in Fig 6.
2 Set the function switch to the AC position.
3 Turn the selector switch to the highest current range
position.
4 Make connections to the multimeter and resistance
board as shown in Fig 6.
5 Close the circuit switch for a moment and watch the 7 Follow the procedural steps given in steps 10 to 12 as
deflection of the pointer. in Task 3 with an exemption that the values should be
entered in Table 4.
6 Open the switch immediately if the pointer reaches
beyond the full scale.
IT & ITES : ICTSM - Exercise 1.2.03 17
 TABLE 4
Alternating current measurement

Sl. Measuring Selected current Multiplication Measured Actual current

No. points range factor (M F) value (M.Value) M.Value x MF (Amps)
1 O-A
2 O-B
3 O-C

TASK 5 : Measurement of resistance using a multimeter

1 Prepare the resistor boards using a tag board with 8 Connect the testing leads to terminal positions O and
resistors as shown in Fig 7. A as shown in Fig 7.
2 Set the selector switch in the resistance position.
3 Plug the black test lead in the common jack, and the red
lead in the positive jack.
4 Short the ends of the two testing leads to check zero
error in resistance mode.
5 Adjust the zero ohms control (zero adjustment knob)
until the pointer indicates zero ohm.

If the pointer cannot be adjusted to zero, the

battery must be replaced.

6 Open the shorted ends of the prods.

Do not keep the ends shorted for a long time, to

avoid draining of the batteries. Before
measuring the resistance of the resistor which
is (inlaid) in the circuit, see that the power 9 Note the reading on the ohm's scale and record it in
supply to the circuit is switched off. In the case Table 5.
of circuits having electrolytic capacitors, they
should be discharged before attempting to 10 Calculate the actual value of resistance taking into
measure resistance. consideration the multiplying factor.

7 Set the selector switch to a suitable resistance range Ex. If the meter reading is 4 when the range switch is
position. in R x 100 position then the

For every change of range switch for resistance resistance value = 4 x 100 = 400 ohms.
measurement, the zero error should be
corrected by shorting the leads. Try to ascertain 11 Repeat the steps from 8 to 10 for OB, OC and OD
the approximate value of resistance from your position.
experience. If the value cannot be ascertained
set the rangeto R x 100 and then change the
range switch to make the pointer to indicate
just in the middle of the scale or beyond.

18 IT & ITES : ICTSM - Exercise 1.2.03

 TABLE 5
Resistance measurement

Sl. Measurement Selected ohms range Meter reading (M R) Actual value

No. points (Ohms) M R x Range (Ohms)

1 0-A

2 0-B

3 0-C

4 0-D

IT & ITES : ICTSM - Exercise 1.2.03 19

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.04

Practice in using digital multimeter

Objectives: At the end of this exercise you shall be able to
• identify the different terminals of the digital multimeter and select the required range and function
• measure the resistance of the given unknown resistor
• measure the unknown AC/DC voltage and current in a circuit.

Requirements

Tools and Instruments Materials

• Available digital multimeter with • Unknown resistors - assorted
test probes - 1 No. (wire wound or carbon) values
• Operation instruction booklets - 2 Nos. • Suitable connecting leads - 1 set
• AC power supply 415/240 volts 50 Hz. - 1 No. • Incandescent lamps, 25W, 40W - 1 No.
• DC power supply 24V 1A - 1 No. 60W & 100W of 240V rating each.

PROCEDURE

TASK 1: Study the digital multimeter

1 Collect the digital multimeter from your instructor.

2 Study the various symbols given on the meter, by
referring to the symbols given in Table 1.
3 Observe the rotary selector switch functions and record
your observations in your practical note book.
a The minimum and maximum AC voltage ranges of
the meter are and
volt.
b The minimum and maximum DC voltage ranges of
the meter are and
volt.
c The minimum and maximum Alternating current
ranges of the meter are and
amp.
d The minimum and maximum Direct current ranges
of the meter are and
amp.
e The minimum and maximum Resistance measure-
ment ranges of the meter are
and ohm.
4 Identify the various input terminals of the meter. (Refer
Fig 1.)
a 10 A input terminal for current measurements (AC or
DC) upto 10A continuous when the function selector
switch is in 10A position. d mA Milliampere input terminals (AC/DC) upto 200
mA continuous when the function selector switch is
b COM Common terminal (black colour), return termi-
in μA or mA position.
nal for all measurements.
c Volt, ohm, continuity, battery and diode test input
terminal (red colour).

20
TASK 2: Measure the resistance of an unknown resistor.

Select proper function and range for resistance While connecting the test leads to resistor
measurement. leads keep your finger tips off the probes.
(Refer Fig 3)
1 Set the function selector rotary switch to OHM (W)
function and any one ohmic range as shown in Fig 2.

4 Read the value of resistance directly from the digital

display and enter in Table 2.

TABLE 2

Sl.No. Resistance under Measured

measurement values

5 Repeat the measurement for four more resistors.

If the measured value of resistance is very less

with high range selected then repeat the
measurement by selecting a suitable lower
Inspect the test leads for damaged insulation if
range.
found replace them.
If a higher value resistance is measured at a
2 Connect the black lead to common terminal and red
lower range setting the over range will be
lead to Ω- V terminal.
indicated by DIGIT ‘1’ in display with other
Never use the ohmmeter section on a live digits blanked.
circuit.
So suitably select a higher range, for accurate
3 Connect firmly the test leads across the resistance measurement purpose.
under measurement.
IT & ITES : ICTSM - Exercise 1.2.04 21
TASK 3: Measurement of DC voltage

Select proper function and range for DC voltage Connect the multimeter selected as a voltmeter
measurement. in parallel with the source voltage.

1 Set the function selector rotary switch to DC voltage (V) 4 Read the value of DC voltage from the display and enter
function and 200 V range as shown in Fig 4. in the Table 3.

Inspect the test leads for damaged insulation. 5 Measure atleast two more DC source voltages, and
enter in Table 3.
2 Connect the black lead to common terminal and the red TABLE 3
lead to Ω- V terminal.
3 Connect the test leads across the source as follows. Sl.No. DC source Measured
Connect red lead to ‘+ ve’ terminal and black lead to ‘ Voltage
- ve’ terminal as shown in Fig 4.
1 volt.

2 volt.

3 volt.

If the measured value of voltage is very less

with high range selected, then, repeat the
measurement by selecting the suitable low
range.

If higher voltage is measured with low range

selection, the over range will be indicated by
DIGIT ‘1’ in display. So suitably select a higher
range.

If ‘-ve’ sign preceeds the reading, it indicates

negative input to meter terminals.

TASK 4: Measurement of AC voltage.

1 Turn the rotary selector switch to AC voltage (V)

If higher voltage is measured with low range
function. To measure unknown AC voltage select the
selection, the over range will be indicated by
highest possible range as shown in Fig 5.
DIGIT ‘1’ in display. So suitably select a higher
range.
2 Repeat the steps 2 to 4 of Task 3.

22 IT & ITES : ICTSM - Exercise 1.2.04

 Fig 5 TABLE 4

Sl.No. AC source Measured

Voltage

1 volt.

2 volt.

3 volt.

TASK 5 : Measurement of Direct current.

Select proper function and range for Direct

current measurement.

1 Turn the rotary selector switch to DC amperes (A)

function. To measure unknown DC current, select the
highest possible range i.e. 10 A.

Inspect the test leads for damaged insulation.

If found replace them.

2 Connect the black lead to the common terminal and the

red lead to 10 A input terminal.

3 Wire up a circuit as shown in the circuit diagram (Fig.6)

and connect the meter test leads in series with the
circuit.

Insert the meter in series with the circuit.

4 Close switch ‘s’ and measure the current by reading the

display and enter in Table 5.

5 Alter the resistance of the circuit by adjusting the

rheostat and note down the corresponding current
drawn by the circuit.

IT & ITES : ICTSM - Exercise 1.2.04 23

 If the measured current is less than 200mA then TABLE 5
connect the red probe to mA input terminal and
turn the rotary switch to (A) function and range Sl.No. Measured current
to 200mA or lower accordingly.
1
If higher current is measured with low range
selection, the over range will be indicated by 2
DIGIT ‘1’ in display. So suitably select a higher
range. 3

Connecting probes may be written in the text

as probes. Also both words could be used
alternatively.

TASK 6: Measurement of Alternating current

Select proper function and range for Alternating

current measurement.

1 Turn the rotary selector switch to AC amperes (A)

function. To measure unknown AC current, select the
highest possible range i.e. 10A.

2 Connect the black lead to common terminal and the red

lead to 10 A input terminal.

When making current measurement, turn the

circuit power off before connecting the meter
in circuit.

3 Wire up a circuit as shown in the circuit diagram (Fig 7)

and connect the meter test leads in series with the
circuit.
4 Close switch ‘s’ and measure current by reading the
display directly and enter in Table 6.
5 Connect different wattage lamps in the circuit and
measure the corresponding current drawn.
TABLE 6

Wattage of lamp Measured current

25W

40W If the measured current is less than 200mA then

connect the red probe to mA input terminal and
60W select range 200mA accordingly.

100W If higher current is measured with low range

selection, the over range will be indicated by
DIGIT ‘1’ in display. So suitably select a higher
range.

24 IT & ITES : ICTSM - Exercise 1.2.04

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.05

Skinning , Tinning and Soldering Wires

Objectives: At the end of this exercise you shall be able to
• cut wires using side cutter
• skin wire ends using electrician knife
• skin wire ends using manual wire stripper
• prepare soldering iron for soldering
• tin the wire end conductors.
• solder wires on to lugs
• lay wires neatly between lugs.

Requirements

Tools/Equipments/Instruments • Single strand wire (1/18 or 1/20 SWG) - 0.5 mt.

• Trainees’ kit - 1 No. • Flexible multi-strand wires
• Electrician’s knife - 1 No. - Red colour (23/36) - 7 mt.
• Manual wire stripper - 1 No. - Black colour (14/36) - 7 mt.
• Soldering iron, 25W - 1 No. - Green colour (23/36) - 3 mt.
• Cleaning brush, 1/2 inch - 1 No. • Rosine cored solder of 21 gauge - 10 gms.
• Soldering flux (pasteform) - as reqd.
Materials/Components • Group board (20 Pin) - 1 No.
• Rigid multistrand wire (14/29 SWG) - 0.5 mt.

After completing this exercise, the trainees should retain the Knife, manual Wire stripper and the
Soldering Iron as a part of the trainees tool kit.

PROCEDURE

TASK 1 : Skinning wires Using knife

1 Check the wires for physical defects if any listed below. 3 As demonstrated by your instructor, hold the side
– Cuts in insulation cutter at the marked position of a wire as shown in Fig
1. Press the cutter handle with a jerk to cut the wire.
– Brittle insulation (cracks in insulation)
4 Repeat step 3 and cut the wires at marked positions.
– Burnt insulation
5 Clean the electrician’s knife handle free of oil, grease
Note: If any wire is found to have serious etc., using a piece of dry cloth or paper.
defect(s) consult your instructor to discard the
wire before taking a new wire. Cleaning will prevent the knife slipping from
the hand while using and hence prevent the
2 Using a measuring tape/scale mark the given flexible hand/fingers from getting cut.
multistrand wires at equal distances of 0.5 metre. Mark
the single strand and rigid 14/29 multistrand wire at 6 Take two single strand and two pieces of multistrand
equal distances of 0.25 mts. (14/29) wires. Mark around the wires at a distance of 10
mm at both the ends.
7 Using knife, remove the insulation of the wire at an angle
of 15 to 20° as shown in Fig 2. Remove the insulation
like sharpening a pencil.

25
 10 Get the skinned single strand wire checked by your
Do not apply excessive cutting force, as this
Instructor.
will damage the conductor.
11 Repeat steps 7 to 9 for the remaining single strand wires
Do not cut through the insulation at 90° to the and the two multistrand (14/29) wire pieces.
wire.
Take extra care while skinning multistrand
8 Repeat step 7 till the insulation at the wire end is wires as the thin strands gets cuts often.
removed as shown in Fig 3.
12 Get the skinned wires checked by your instructor.

The skinning technique using a knife is generally

used for large diameter wires with thick
insulation. This technique is not suitable for
skinning wires with smaller conductor(s) and
wires with thin insulation, which are generally
9 Repeat steps 7 and 8 for the other end of the single used in electronic circuits.
strand wire.

TASK 2 : Skinning Multi-strand wires using a manual Wire stripper

1 Mark at a distance of 10 mm at the ends of all flexible 6 Holding the wire firmly, press the handle of the stripper
multistrand wire pieces to be skinned. with a jerk and pull away the manual stripper as shown
2 Press the handle of the manual wire stripper and adjust in Fig 5.
the screw of the stripper such that the ‘V notch’ gap is
much larger than the outside diameter of the black wire.
3 Insert one end of a wire into the V notch. Adjust the
screw of the stripper such that the jaws of the V notch
just touch the insulation of the wire. Remove the wire
from the notch.
4 Turn-in the screw of the stripper by one to two turns,
such that the gap of the V notch is slightly reduced.
5 Release the pressure on the handle. Insert one of the
wire ends into the V notch such that the 10 mm marking
7 Check if one or more strands of the conductor are cut
line on the wire is exactly at the jaws of the V notch as
while stripping. If so, increase the V notch gap suitably.
shown in Fig 4.
8 Repeat steps 5, 6 and 7 and strip the insulation at the
other end of the wire.
9 Get the stripped wire checked by your instructors.
10 Repeat steps 5 to 8 and strip the end insulation of all the
flexible multistrand wire pieces.

Refer IMP on Electrician trade for other

commonly used wire strippers and methods of
skinning.

TASK 3 : Inspect Soldering iron defects and prepare for soldering

1 As demonstrated by your instructor, check to confirm 3 Refer to the Chart on "Preparing soldering iron for
that the given soldering iron has no defects. soldering" given at the end of this exercise. Follow the
flow diagram and make ready the soldering iron for
2 Place the soldering iron in its stand. Connect the
soldering.
soldering iron to mains supply (230V, AC, 50Hz) and
switch it ON. Wait for five minutes for the soldering iron 4 Get the prepared soldering iron checked by your
to heat up. instructor.

26 IT & ITES : ICTSM - Exercise 1.2.05

TASK 4 : Cleaning the wire end conductors and Tinning

1 Take a piece of a single strand wire skinned at both

ends. Clean the exposed end conductor using a dry
cloth/paper to remove stray particles, moisture, grease
etc.

Presence of stray particles etc on the wire

prevents free flow of solder while tinning.

2 If the exposed conductor of the wire is not shiny, scrap

the exposed conductor all around using a knife/blade to
remove oxide layer/varnish.

Presence of oxide layer/varnish results in poor

flow of solder(wetting).

3 Place the wire in the tinning stand as shown in Fig 6a

or hold the wire in the hand as shown in Fig 6b.
4 Apply a thin layer of flux on the exposed conductor
except for a very small portion close to the insulation
as shown in Fig 7.

Flux dissolves any remaining oxides on the

conductor surface.

5 Hold the face of the heated soldering iron bit on to the

bottom of the exposed conductor as in Fig 8a and wait
for 1 to 2 seconds for the exposed conductor to get
heated up.

6 Touch the tip of the solder wire on to the heated exposed

conductor. As the solder melts and forms a thin layer
over the conductor , move the solder and iron along the
conductor as shown in Fig 8b. Pull away the solder wire
and bit from the conductor once you come near the
insulation.

Do not touch the solder directly to the bit as

large quantity of solder melts and forms a lump
on the wire and bit.

Do not take the iron very close to insulation of

the wire as the insulation may get melted.

7 Check if a thin layer of bright shiny solder (tinned)

surface is formed on conductor.

If the tinned surface is dull, redo steps 4 - 7.

8 Repeat steps 3 to 7 and tin the other end of the single

strand wire.
13 Repeat necessary steps above to tin both ends of the
9 Repeat steps above to tin other single strand wire. wire.
10 Get the tinned wires checked by your instructor. 14 Get the tinned wire ends checked by your instructor
11 Take a piece of multi-strand wire, clean, scrap the 15 Tin the remaining multi-strand wires and get your work
exposed conductors. checked by your instructor.
12 Twist the conductors in the direction of existing twist as
shown in Fig 9.

IT & ITES : ICTSM - Exercise 1.2.05 27

TASK 5: Soldering wires on Lug/Tag boards

1 Prepare and keep ready soldering iron for soldering.

Allow the solder joint to cool naturally. If the
2 Check if the lugs of the lug board are bright/already joint is cooled by blowing air, the joint will
tinned. If not, scrap the outer face of the lugs, using knife become a dry solder joint and, hence, will be
such that, the oxide layer/varnish is removed. Wipe the a weak joint. Shaking of wire/lug board before
lugs with a piece of dry cloth. cooling, results in dry solder joint.
3 Apply a thin layer of flux on the outer face of the lug as
shown in Fig 10a. 8 Get the soldered joint checked by your instructor.

4 To tin the lugs, hold the bit of soldering iron at the inner
face of lug as shown in Fig 10b and wait for 1 to 2
seconds. Hold the tip of solder wire at the outer face of
the lug as shown in Fig 10b. As the solder melts and
flows on the lug, take out the solder wire and iron from
the lug.
Allow a very small quantity of solder to flow over the lug.

Do not shake the board till the melted solder

dries up by itself.

Do not blow air to cool the solder on the lug.

5 Repeat steps 3 and 4 and tin all the lugs on the lug
board. Get the tinned lugs checked by your instructor.
6 Insert and bend one of the tinned single strand wire in
the hole of lug -1 as shown in Fig 11. (side entry
method)
Refer Fig-14 for lug numbers.

7 As shown in Fig 12a, hold the bit of the soldering iron

at the inner face of the lug for 1 to 2 seconds . Apply
solder at the outer face of the lug as shown in Fig 12b.
Once the solder melts and flows over the tinned wire and
lug as in Fig 12c, take away the iron and solder from the
lug.

9 Take the wire along the path from, lug 1 to lug 11 as

shown in Fig 13. Cut the wire at a point 10 mm ahead
of lug 11. Lay the wire using flat nose player.
28 IT & ITES : ICTSM - Exercise 1.2.05
10 Skin the wire and tin the skinned end.
Note : Excess of flux may corrode the lugs.
11 Insert the tinned wire end into the hole of lug 11, bend
the wire as done in step 7 and solder the wire . 13 Get your work checked by your instructor.
12 Follow steps 6 to 12 above to solder and bend the wires
to obtain a wiring layout as close as possible to that
shown in Fig 14. Clean the soldered points using a
brush to remove excess flux.

IT & ITES : ICTSM - Exercise 1.2.05 29

 CHART - 1
PREPARING SOLDERING IRON BEFORE SOLDERING

! MAINS ON

DON’T KEEP IRON

DIRECTLY ON THE
WORKING TABLE.
È
DAMP SPONGE
CLEANS TIP
FROM DUST,
DRY OXIDES.
CLEAN TIP

Æ
ALLOW TO HEAT
FOR 2 – 5 MIN.

TIP TEMP > 200 0 C USE SUITABLE

DON’T TOUCH TIP SOLDER TYPE
OR TAKE IRON WHILE TESTING.
NEAR SKIN.
TEST SOLDER MELTING

DID
NO SOLDER
Å MELT INSTANT-
ANEOUSLY
?
YES
È

REMOVES
EXCESS SOLDER
PRESENT ON
THE TIP.
CLEAN TIP

TIP
SHINY ?
NO YES
È È

TIP MAY BE SOLDERING

DEFECTIVE IRON READY
CONSULT FOR USE.
INSTRUCTOR.

30 IT & ITES : ICTSM - Exercise 1.2.05

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.06

Desoldering Wires from Lug board and Soldering Practice

Objectives: At the end of this exercise you shall be able to
• desolder wires using soldering iron and nose plier
• desolder wires using desoldering pump.
• solder multiple wires at points on the lug board.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Group board
• Hand held type Desoldering pump (end product of Ex:1.2.05 with wires
(see note at the end of Exercise) soldered to lugs)
• Soldering flux - as reqd.

PROCEDURE

TASK 1 : Desoldering using a Soldering iron and Nose plier

1 Keep the soldering iron ready for soldering.

2 Wipe the tip of the heated soldering iron on a rag, so as
to remove the solder sticking on the tip.
3 Hold the exposed conductor of the wire with a sharp tip
flat nose plier or tweezers as shown in Fig 1.

This prevents excessive heat transfer to the

wire thus preventing melting of the wire
insulation.

4 Hold the heated soldering iron tip on the soldered joint

at lug 1 as shown in Fig 2(a) till the solder at the joint
starts melting. Pull away the tip of the iron from the joint 6 Hold the cleaned tip of the iron at the outer face of the
carrying some of the melted solder with it as shown in lug and pull the wire gently using a nose plier or
Fig 2(b). Remove the solder on the iron tip by wiping the tweezers as shown in Fig 3.
bit on a rag.
7 Remove the residual solder sticking to lug 1 using
5 Repeat step 4, till the joint and the hole are almost free soldering iron such that the lug hole is clear of solder.
from solder.
8 Get the desoldered point checked by your instructor.
This makes the wire almost free for pulling it 9 Repeat steps 2 to 7 and desolder wires at lugs 2 to 10.
out, from the lug.

31
TASK 2 : Desoldering using hand held desoldering pump

1 Press the handle of the desoldering pump fully as

shown in Fig 4 till it makes a click sound, and release
the handle.

2 Hold the pump nozzle at lug no.11 of lug board as shown 6 Get the desoldered point checked by your instructor.
in Fig 5a.
7 Repeat steps 1 to 5 to desolder wires at lug no.11 to
3 Hold the heated tip of the iron at the inner face of lug as 101.
shown in Fig 5b till the solder melts. With the pump
nozzle touching the melting solder at the joint, press 8 Get your work checked by your instructor.
the pump button. 9 As a practice of soldering, solder back the desoldered
wires on the lug board as shown in Fig 7. After soldering
The pump sucks the molten solder. any lug which has more than 1 wire termination (such
as lug no.44,22,9,7,6,4) get it checked by the instructor.

4 Take away the iron and pump from the lug. Check if the
solder at the joint is sucked off and the lug hole is clear.
If not repeat steps 1 to 3 till the hole is almost clear. 10 Get the wired board checked by the instructor for quality
5 Clean the tip of iron and hold at the outer face of the lug. of soldering and neatness of wire laying.
Pull out the wire from the lug as shown in Fig 6. 11 Desolder all the wires from the lug board. Clean the lug
baord and get it checked by the instructor.
Do not force the wire out as the wire may get
cut. If the wire is not coming out easily, repeat
steps 1 to 5.

On completion of this exercise, the trainees shall retain the hand held type desoldering iron as a part of
Trainees tool kit as a desoldering pump is very frequently used by Electronics related technicians.

32 IT & ITES : ICTSM - Exercise 1.2.06

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.07

Identify, find value and measure resistance of fixed value resistors

Objectives: At the end of this exercise you shall be able to
• identify different types of fixed value resistors by their appearance
• check the physical condition of fixed resistors
• determine resistance value by colour code
• determine value by typographic/numeric code.
• pick a specified value resistor from the given lot of resistors
• measure the resistance using an ohmmeter.

Requirements

Materials/Components
• Assorted types & values of fixed
value resistors - as reqd.

PROCEDURE

TASK 1 : Identify resistors by their appearance and check physical defects

1 Take a resistors from the given lot and compare its 6 For the same resistor, check for clear visibility of colour
approximate physical appearance with the resistors bands or printed resistor value on the body of the
shown in Chart 1 of lesson 1.2.07 Identify type name resistor. Tick the appropriate statement in record sheet.
and record it in Table 1 of record sheet.
7 From the conditions of the resistor noted in record sheet
2 Repeat step 1 for the remaining given resistors. give your conclusion about the usability of this resistor
3 Get your work checked by your instructor. in record sheet.
4 Take a resistor. Refer Chart 1 at the end of this exercise 8 Repeat steps 4 to 7 for the remaining resistors and get
and check for lead damages if any. Record the identified your work checked by the instructor.
lead defect code in record sheet.
5 For the same resistor, refer Chart 2 at the end of this
exercise and check for physical damages, if any, on the
body of the resistor. Record the identified defect code
in record sheet.

TASK 2 : Calculate resistor value from colour bands

1 Take a colour coded resistor from the given lot and

identify the colours of bands starting from one end of the
resistor as shown in Fig 1. Record the colours of the
bands in Table 2 of record sheet.
2 Refer appendix D of this book and calculate the nomi-
nal, minimum, maximum value of the resistor. Record
values in Table 2 of record sheet.
3 Repeat steps 1 & 2 for the remaining colour coded
resistors and get your work checked by your instructor.

33
TASK 3 :- Interpret typographically coded resistors.

1 Take a typographically coded resistor from the given lot. 3 From the tolerance value noted, calculate and record
Record the printed codes value of resistance and the minimum and maximum value of the resistor.
tolerance in Table 3 of record sheet.
4 Repeat steps 1 to 3 for the remaining typographically
2 Check if the recorded code match with any of the types coded resistors and get your work checked by your
of resistor value codes given in appendix D of this book. instructor.
From the examples given in appendix D, interpret the
nominal value of the resistor and record in record sheet.

If none of the given codes in appendix D of this

book match, the codes may be the
manufacturer’s specific. Consult your instructor.

TASK 4: Pick specific value resistors

1 For the resistor value at Sl.No.1 of Table 4 in record 3 Check if there are more number of resistors matching
sheet, write the colour bands. the colour band. If yes, pick them and place them
Refer appendix D of this book for colour code values. separately. Record the number of resistors matching
the required colour bands in record sheet.
2 In the given lot of resistor, pick a resistor matching the
colour bands recorded. 4 Get your work checked by the instructor.

If no matching resistor is found mark suitably in coloumn 5 Repeat steps 1 to 3 for other values of resistors listed
7 of Table 4. in the table and get it checked by your instructor.

TASK 5: Measure fixed value resistance using ohmmeter/multimeter.

1 Check the physical condition of the given resistors one 5 Repeat steps 2 to 4 for the remaining given resistors.
by one and discard the defective resistors.
6 Connect prods to the ohmmeter/multimeter terminals.
2 Take a resistor from the assorted lot. Find and record Set the meter to the suitable resistance range so as to
its standard, min. and max. resistance values in the measure the resistance value of group 1 resistors of
appropriate group of Table 5 in record sheet. Table 5.
3 Scrap the resistor leads using a knife as shown in Fig 7 Short meter prods as shown in Fig 3. Adjust the zero set
2 to remove the oxide /varnish layers on the leads. knob of the meter and carry out resistance zero setting
of meter.
The oxide/varnish layers behave as insulators. If the
leads are not scraped before measuring the resistor The position of zero set knob may be different in your
values, the meter may show very high resistance meter.
instead of the actual resistance of the resistor.
9 Clip the resistor at Sl.no.1 of group 1 to the crocodile
4 Using a cloth or paper, wipe the leads to make them free clips as shown in Fig. 4
from moisture, oil etc.

34 IT & ITES : ICTSM - Exercise 1.2.07

 Do not touch the leads of the resistor while
measuring. This will make the meter show your
body resistance and not the resistor under
measurement.

9 Record the value shown by the meter in the appropriate

column of table 5.
10 Repeat steps 8 and 9 for all the resistors under group
1.
11 Repeat steps 6 to 10 for the different groups of resistors
recorded in Table 5.

Resistance zero setting must be done, every

time the measuring range of ohmmeter is
changed.
Retain the resistors used in this exercise as the
12 For the entries made in Table 5, for different groups, same resistors are used in further exercises.
check if the measured value and the calculated value
of the resistors are matching. Enter your observations
in the last column of the Table.
13 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.2.07 35

 CHART 1

LEAD DEFECTS DEFECT REMARKS USABILITY

CODE

Shake at NECK JOINT May become

(Lead Shakey)
electrically open,
while handling, UNFIT

LS
bending.

Lead with WEAK POINTS Lead may get

cut while
WEAK POINTS

(Lead Weak)
handling, UNFIT
Bending.

LW

Strong NECK JOINT &

(Strong Leads)

no WEAK POINTS
----- FIT
SL

CHART 2

PHYSICAL DEFECT DEFECT CODE REMARKS USABILITY

Skin coating peeled off SPE Value might have deviated UNFIT
Body cracked BCR May be open or value deviated UNFIT
CAP Shacking /cracked CSH May be open or loose contact UNFIT
Body charred or BCH May be open, short, UNFIT
become blackish value deviated
None of the above defects NIL ----- FIT

36 IT & ITES : ICTSM - Exercise 1.2.07

 Record Sheet for Exercise 1.2.07

1 Table 1
Resistor's Type name Lead Physical Resistor value Overall usability
label No. defect code defect code visibility of resistor
Sample Ceramic LW BCH Visible unfit
entry with
Axial leads √ Not visible

Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible
Visible
Not visible

2 Table 2

Resistor Colour Colour Colour Colour Percentage Standard Minimum Maximum

label of of of of tolerance value of value of value of
number 1st Band 2nd Band 3rd Band 4th Band resistor resistor resistor
Sample entry yellow violet red silver 10% 4.7K Ω 4230 Ω 5170 Ω

IT & ITES : ICTSM - Exercise 1.2.07 37

3 Table 3
Resistor Printed Printed Standard Minimum Maximum
label value tolerance value value value
number code code in ohms in ohms in ohms

Sample 6 KΩ 5% 6.8KΩ 6460Ω 7140Ω

4 Table 4
Sl. Required Colour of the bands should be Availablity Numbers
No. value
1st 2nd 3rd 4th

(1) (2) (3) (4) (5) (6) (7) (8)

Sample 47Ω 10% Yellow Violet Black Silver 3
√

1 2.2 k ohms
± 10 %

2 220 k ohms
± 20 %

3 330 ohms
± 10 %

4 82 ohms
±5%

5 1 M ohms
± 10 %

38 IT & ITES : ICTSM - Exercise 1.2.07

5 Table 5
Sl. Standard % tolerance Calculated value Measured Values matching
No. value Min. Max. value (Yes/No)

GROUP - 1 (Values < 100 Ohms)

Sample 47 Ω 10% 42.3Ω 51.7Ω 55 Ω No

GROUP - 2 (Values between 100Ω to 1000Ω )

1

GROUP - 3 (Values between 1KΩ to 10 KΩ )

1

GROUP - 4 (Values > 10 KΩ )

1

Space for recording additional Information:

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.2.07 39

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.08

Verification of Ohm's Law

Objectives: At the end of this exercise you shall be able to
• solder resistors on lugboard
• measure current in resistive circuits
• verify Ohm’s Law.

Requirements

Tools/Equipments/Instruments • Hook-up wires - 20 cms.

• Patch cords - as reqd.
• Trainees kit
• Lug board - 1 No.
• Milliammeters
• Resistors
0 - 30 mA - 1 No.
1K, 1/2 watt - 4 Nos.
0 - 10 mA - 1 No.
2.2 K, 1/2 watt - 1 No.
• Dual Variable DC (PSU)
3.3 K, 1/2 watt - 1 No.
0 - 30V,1A - 1 No./batch of 2.
4.7K, 1/2 watt - 1 No.
Materials/Components • Rosin cored solder, 18 gauge - 10 gms
• SPST toggle switch, • Soldering flux - as reqd.
1 Amps rating - 1 No.

PROCEDURE

TASK 1 : Solder resistors on Lug board

1 Switch-on soldering iron and prepare it for soldering. 5 Solder the resistors on the lug board in the order as
2 Clean and tin the lugs on the lug board. shown in Fig 1.

3 Check the physical condition of the given resistors. 6 Inspect the soldered points and fill up the Inspection
Exchange resistors found defective. sheet given in record sheet.

4 Check the resistance of the given resistors using meter. 7 Get your work checked by your instructor.
Exchange resistors found having abnormal values.
Value of some resistors will be abnormally different from
the colour coded values printed. This is due to manufac-
turing error. Therefore, check resistor values with meter
before using the resistors.

TASK 2 : Measure current in the circuit with one resistor.

1 Check physical and electrical condition of the given

milliammeters, meter prods, patch cords, toggle switch
soldered on the lug board.
2 Measure and record the resistance value of the first 1 K
resistor (soldered on lug board) in Column 2 of Table 1
in record sheet.
3 Refer the circuit and wiring layout diagrams given in Fig
2 and wire the circuit using suitable patch cords.

While making connections, keep the power

supply and the SPST switch in OFF position.
If the meter terminal connections are reversed
the current meter will deflect below zero and
may get permanently damaged.

40
4 Calculate the theoretical current that is expected to flow 8 Switch ON SPST. Measure and record the circuit
in the circuit for a dc supply of 6 volts. Record the current in Table 1 of record sheet.
calculated value in Column 3 of Table 1.
9 Get the reading checked by your instructor.
5 Knowing the expected circuit current from step 4,
10 Put SPST to OFF. Increase the output of the PSU to 9
Check if the measuring range of the milliammeter
volts. Repeat steps 4,5,7 & 8 for the set PSU output
connected in the circuit can safely measure the circuit
voltage of 9V.
current. If necessary, replace the connected milliam-
meter by a suitable lower or higher range meter. Record 11 Put SPST to OFF. Increase the output of PSU to 12
the range of meter connected in Column 4 of Table 1. volts. Repeat steps 4,5,7 & 8 for the set PSU output
voltage of 12V.
6 Get the wired circuit checked by your instructor.
12 Switch OFF SPST and PSU.
7 With SPST in OFF condition, switch ON PSU. Set the
output voltage to 6V. 13 Get the readings checked by your instructor.
14 Remove the clips connected across resistor R1.
The voltmeter available on PSU may not show
accurate reading in low voltages. Check for the Do not disconnect the interconnections
correct voltage setting using multimeter. made with PSU, meter and switch as the
same is required for Task-2.

TASK 3 : Measure circuit current with varying circuit resistances.

1 Measure and record (in Table 2) the values of all 1 K 14 Disconnect the circuit connections including the wires
resistors soldered on the lug board. soldered across the 1 K resistor ends.
2 Solder wires at the ends of resistors on the lug board as 15 From the recorded readings in Table 2, plot a graph of
shown in Fig 3. circuit current versus circuit resistance in the graph
given in record sheet.
This makes all 1K resistors to be in series.
16 From the readings noted in Tables 1 & 2 and from the
3 Connect the clips across series combination of R1 and
graph plotted, complete the sentences given in the
R2 as shown in Fig 4.
record sheet. Get your work checked by your instructor.
Keep the SPST in the OFF position while making circuit
connections. Do not de-solder the resistors from the lug
board as the board with soldered resistors is
5 Calculate the theoretical circuit current and record in
required for subsiquent exercises.
the appropriate column of Table 2.
6 If found necessary change the milliammeter connected
in the circuit to measure the calculated circuit current
at step 5.
7 Switch ON PSU and set output to 12V. Switch ON
SPST switch. Measure and record the circuit current in
Table 2. Switch OFF the SPST switch.
8 Change the position of the clip(P) such that three 1K
resistors are in series (R1+R2+R3).
9 Repeat steps 5, 6,and 7 and record the readings in the
appropriate column of Table 2.
10 Change clip(P) in circuit to its next position such that
four 1K resistors are in series(R1+R2+R3+R4).
11 Repeat steps 5, 6,and 7 and record the readings in the
appropriate column of Table 2.
12 Switch OFF SPST and PSU.
Always make it a practice to switch OFF power supply
to the circuit once the work is completed.
13 Get your readings checked by your instructor.

IT & ITES : ICTSM - Exercise 1.2.08 41

 Record Sheet for Exercise 1.2.08

1 Instructors remark on the quality of soldered joints made

2 Solder joint inspection report sheet:

FEATURE LIMITS PASS FAIL
No of points No of points

Wetting - 95% of soldered joint covered by solder,

- No sign of de-wetting.
Fillets - Concave and even
- No solder stepping (dihedral angles less
than 20 degrees).
- No signs of peaking.
Solder quantity - Fillet tapers to meet the end of the lead.
- No overlap from lead or solder pad.
Solder surface - Smooth and shiny.
- Light grey in colour.
- No signs of surface cracking.
Flux - Removed completely.
- No sign of flux trapped in joint.
Leads and solder - Undamaged.
tracks - Clean.
- Free of excess flux or solder.

3 Table 1
Set output Measured Calculated Range of Measured Difference
of power resistance theoretical Milliammeter circuit between
supply unit value circuit current range chosen current Col(3) and Col(5)
(1) (2) (3) (4) (5) (6)

3
3 volts 995Ω = 0.003015 0-10 mA 2.95 mA 0.05 mA
995
= 3.01mA

6 volts

9 volts

12 volts

42 IT & ITES : ICTSM - Exercise 1.2.08

4 Table 2
SET SUPPLY VOLTAGE TO 12volts CONSTANT
Sl. VALUE OF RESISTANCE THEORETICAL MEASURED
NO. RESISTORS IN CIRCUIT CIRCUIT CURRENT CIRCUIT CURRENT
1 R =
1
2 R +R =
1 2
3 R +R +R =
1 2 3
4 R +R +R +R =
1 2 3 4
NOTE: For Sl.No.1 of Table 2, copy the corresponding reading recorded in Table 1.

5 GRAPH

6 Refer Table-2 and the Graph plotted above while completing the sentences given below;

i) Keeping the circuit voltage constant, the current in a iii) The graph shows a __________ relationship between
resistive circuit becomes half, when the circuit resis- resistance and current. This also indicates that the
tance is ___________. resistor is a _________ device.

ii) The higher the resistance of the circuit, ________ is the

current through the circuit.

7 Space for recording additional informations if any:

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.2.08 43

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.09

Verification of Kirchhoff’s Current and Voltage law

Objectives: At the end of this exercise you shall be able to
• simplify a given circuit and calculate the circuit current
• wire a circuit given the circuit diagram
• verify Kirchhoff’s current law
• verify Kirchoff’s voltage law.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Lug board soldered with resistors
• Variable DC power supply unit (end product of Ex.1.2.08)
0-30V/1A - 2 Nos./batch. • Toggle switch, SPST , 1amp. - 2 Nos.
• Milliammeters • Patch cords - as reqd.
0 - 10 mA - 3 Nos./batch.
0 - 30 mA - 1 No./batch..

PROCEDURE

TASK 1: Verify Kirchhoff’s Current Law with two branch currents.

1 Connect the PSU, milliammeters, SPST switch and Keep the SPST and PSU in the OFF position while
resistors as illustrated in the circuit schematic and the making circuit connections.
layout diagram as shown in Fig 1.
2 Switch ON PSU and set output to 12 volts.
3 Simplify the circuit at Fig 1 and calculate the theoreti-
cal total circuit current and branch currents of the
circuit for a set dc supply of 12 volts. Record values in
Table 1 of record sheet.
4 Check if the current meters connected are suitable to
measure the calculated current. Change the meter if
necessary.
5 Get the circuit connections checked by your
instructor.
6 Switch ON SPST. Measure and record the total
circuit current (IT) and branch currents IB1 and IB2 in
Table 1.
7 Switch OFF the SPST. Set the output of the RPSU to
9 volts.
8 Calculate the theoretical circuit currents for the set
supply voltage of 9V. Record values in Table 1 of record
sheet.
9 Repeat steps 4 & 6.
10 Switch OFF SPST and PSU.
11 Write Kirchhoff’s current equations for the nodes P and
Q in the record sheet. Verify the equation substituting
measured current values.
12 Get your readings and equations checked by your
instructor.

44
TASK 2 : Verify Kirchhoff’s current Law with three branch currents

1 Make circuit connections on the lug board as per the

schematic in Fig 2.
Make it a practice to keep the SPST and PSU switches
in the OFF position while making circuit connections.
2 Get the wired circuit checked by your instructor.
3 With the SPST in OFF position, set the output of PSU
to 12 volts.
4 Switch ON the SPST switch. Measure and record
currents IT, IB1, IB2 and IB3 in Table 2 of O&T sheet.
5 Switch OFF SPST and PSU.
6 Write Kirchhoff’s current equations at nodes P and Q
in the record sheet. Verify the equation using meas-
ured current values.
7 Get your readings and equations checked by your
instructor.

TASK 3 : Verify Kirchhoff’s Voltage Law with one voltage source

1 Measure and record in Table 3, values of resistors R4, 4 Get the circuit connections and polarities marked,
R5 and R6 soldered on the lug board. checked by your instructor.
5 Switch ON PSU and set output to 12V. Switch ON
SPST. Following the voltage polarities marked across
the resistors in record sheet, measure and record the
voltage drop across resistors R4, R5 & R6 in Table 3.

Use the multimeter of trainees kit for measuring

voltage drops. While measuring, if the meter
deflects below zero, recheck the polarity
marked at step 3 and repeat step 5.

6 Switch OFF SPST and PSU.

7 Write Kirchhoff’s loop equations for the closed paths a-
2 Make the circuit connections as shown in Fig 3. c-d-b-a, a-e-f-b-a and c-e-f-d-c in record sheet. Substi-
3 Mark the polarity of the voltage drops across resistors tute the voltage readings recorded in Table 3 in the
R4, R5 and R6 in the copy of Fig 3 given in the record equations for verification.
sheet. 8 Get your readings and equations checked by your
instructor.

TASK 4: Verify Voltage Law with two voltage sources

1 Modify the circuit connections made in Task 3, to

obtain a circuit as shown in Fig 4.
Keep both the PSU’s and the two SPST’s in OFF
position while making circuit connections.
2 Mark the polarity of the voltage drops across the
resistors R4, R5 and R6 in the copy of Fig 4 given in the
record sheet.

IT & ITES : ICTSM - Exercise 1.2.09 45

3 Set the output of PSU-1 to 12 volts and PSU-2 to 6 5 Switch OFF the SPSTs and PSUs.
volts.
6 Write Kirchhoff’s voltage equations for the closed
4 Switch ON both SPSTs. Following the voltage polarities paths a-c-d-b-a, a-e-f-b-a and c-e-f-d-c in the record
marked across the resistor, measure and record the sheet.
voltage drop across the resistors R4, R5 & R6 in Table
7 Get your readings and equations checked by your
4.
instructor.
While measuring voltage across resistor, if the 8 Reverse the polarities of PSU 2 in the circuit at Fig 4
meter deflects below zero, recheck the polarity and repeat step 1 to 7.
marked at step 2 and repeat step 4.

Important procedural information to be noted after completion of this exercise and while making circuit connections
and testing circuits in further exercises; These general points will not be repeated in future exercise.

1 While making circuit connections, always ensure that

(i) The power supply AC or DC to the circuit is kept OFF.
(ii) All the switches in the circuit should be kept in OFF position.

2 After taking readings, before you leave the testing table, ensure that, the power supply is switched OFF.

3 After completing the experiment get it checked by your instructor carry out the following;

(i) Ensure that the output voltage control of PSU is adjusted to zero volts output position and then PSU is
switched OFF.
(ii) Mains supply to PSU is switched OFF.
(iii) Soldering iron connection to mains supply is removed.
(iv) All the path cords are removed and kept in its storing place.
(v) Working table is clean from solder globules, flux, wire pieces etc.

46 IT & ITES : ICTSM - Exercise 1.2.09

 Record Sheet for Exercise 1.2.09

TASK 1
1 Table 1
Set Calculated values of circuit current Measured values of circuit currents
circuit
voltage Total circuit I I Total circuit I I
B1 B2 B1 B2
current current

12V

9V

2. For Fig1 Kirchhoff’s current equation at,

(a) node P for set circuit voltage of 12 V:

(b) node Q for set circuit voltage of 12 V:

(c) node P for set circuit voltage of 9V:

(d) node Q for set circuit voltage of 9V:

TASK 2

1 Table 2
Set circuit Total circuit Branch currents
voltage current (I )
T
I I I
B1 B2 B3
12 V

2 For Fig 2 Kirchhoff’s current equation at,

(a) node P

(b) node Q

IT & ITES : ICTSM - Exercise 1.2.09 47

TASK 3

1 Table 3
Set circuit Measured values of Voltage measured across
voltage R R R VR4 VR5 VR6
4 5 6

2 Mark the polarity of voltage drops across resistors 3 Krichhoff’s loop equations for;
in the circuit given below:
(a) The closed path a-c-d-b-a

(b) The closed path a-e-f-b-a

(c) The closed path c-e-f-d-c

TASK 4
1 Table 4
Set output of Set output of Voltage measured across
RPSU 1 RPSU 2 VR4 VR5 VR6

2 Mark the voltage drop across resistors in the circuit 3 Kirchhoff’s voltage equation for,
given below;
(a) the closed path a-c-d-b-a

(b) the closed path a-e-f-b-a

(Trainee) (Instructor)

48 IT & ITES : ICTSM - Exercise 1.2.09

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.10

Measure power directly and indirectly

Objectives: At the end of this exercise you shall be able to
• identify the terminals and connect a wattmeter in a circuit
• connect a voltmeter in a circuit (R)
• connect an ammeter in a circuit (R)
• determine the power consumed by a component/circuit by indirect method (voltmeter, ammeter)
• measure power consumed using a wattmeter.

Requirements

Tools/Instruments Equipments/Machines
• Cutting pliers 150 mm - 1 No. • Heater 230V - 1000W - 1 No.
• Knife/wire stripper - 1 No. • Rheostat 5A, 10 ohms - 1 No.
• Wattmeter 250V, 5A, 1250W
Materials/Components
(Dynamometer type) - 1 No.
• Voltmeter 0-300V M.C. - 1 No. • Lamps 500W, 230/250V - 1 No.
• Ammeter 0-5A M.C. - 1 No. • Lamps 200W, 230/250V - 1 No.
• Lamp-holder BC & Goliatic type - 2 Nos. each
• Flexible cable 80/0.2 of 250V grade - as reqd.
• SPT switches 6A 250V - 1 No.

PROCEDURE

TASK 1: Indirect method of power measurement

1 Connect the voltmeter rheostat, heater and ammeter TABLE 1

as shown in Fig 1.
Reading of Reading of Calculated Reading of
V A Power in walts Wattmeter

3 Read the meters and record the values in Table 1.

4 Open the switch (OFF) and disconnect the circuit.
5 Calculate the power using the formula
Power = Voltage V x Current I i.e. P = VxI watts.

2 Close the switch and adjust the variable resistance VR Indirect power measurement is suitable for DC
to set the voltage indicated by the voltmeter to an exact circuits, and for AC circuits comprising of pure
division of scale. resistive loads.

TASK 2 : Direct method of power measurement

1 Identify the terminals of a wattmeter. 4 Read the wattmeter and record the value in the table.
2 Connect the wattmeter, voltmeter, ammeter, rheostat 5 Open the switch and disconnect the circuit.
and load as shown in Fig 2.
6 Compare the power calculated by the indirect method
3 Close the switch and adjust the variable resistance to with the wattmeter reading.
set the voltage across load L (indicated by voltmeter)
7 Repeat the experiment for 500W and 200W lamps
equal to the value recorded in the indirect method.
loads and note down the values in Table 1

49
 8 Results

50 IT & ITES : ICTSM - Exercise 1.2.10

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.11

Identification and testing of special type of Resistors

Objectives: At the end of this exercise you shall be able to
• identify and test the NTC and PTC Thermistor
• identify and test the LDR.

Requirements

Tools/Equipments/Instruments • Heater, dry blower, or any type of

heating device - 1 No.
• NTC Thermistor - 1 No.
• Multimeter - 1 No
• PTC Thermistor - 1 No.
• Group board - 1 No.
• VDR - 1 No.

PROCEDURE

TASK 1: To identify and test NTC and PTC Thermistor (Fig 1)

1 Set the multimeter im resistance range

2 Connect the multimeter across the Thermistor as
shown in (Fig 2).

3 First, before applying any heat to the thermistor, check

its rated value. For example, the thermistor may be
100Ω, 1KΩ, 10KΩ, 100KΩ, etc.
4 Record the cold resistance of Thermistor
5 Before any heat is applied to the thermistor, its resist-
ance value should be very closely near its rated resist-
ance value.
Use the tips given below for making conclusion
6 This is the first preliminary test to check whether a
thermistor is good. If it is near its rated resistance value, When you apply heat to the body of a thermistor, its
then so far, it is good. If it is very far or much different resistance should begin to steadily decline within seconds
than its rated value, then the thermistor is faulty and after heat is applied. If the NTC thermistor follows this
should be discarded. behavior, then it is good. If it does not, it is faulty and should
be discarded.
7 Then apply heat to the thermistor. (This can be done
either by a heater, dry blower, or any type of heating First check, with an ohmmeter, the thermistor without any
device.) heat applied. With a PTC thermistor at room temperature
or below, the thermistor should measure a very low
8 Observe the resistance value. resistance.
9 Repeat the above steps for testing of PTC Thermistor. When you apply heat to the body of, to the thermistor's
10 First check, with an ohmmeter, the thermistor without body. The resistance of the PTC thermistor should gradually
any heat applied. With a PTC thermistor at room and steadily rise, within seconds of being applied.
temperature or below, the thermistor should measure a If the resistance increases steadily, then the PTC thermistor
very low resistance. is good. If it does not, it is faulty and should be discarded.
11 Observe the resistance value

51
TASK 2: To identify and test LDR

Test 1
1 Keep the multimeter at Ohms mode.
2 The LDR must be subjected to a bright light source
(day light is enough).
3 Connect the LDR leads to the multimeter terminals as
shown in the Fig 3.
4 Observe resistance value
5 Now the multimeter will show a low resistance reading
around 500 Ohms.
Test 2
1 Keep the multimeter at Ohms mode.
2 The LDR must be subjected to darkness by covering it
with an opaque paper.
3 Connect the LDR leads to the multimeter terminals as
shown in the figure. 5 Now the multimeter will show a high resistance reading
4 Observe resistance value around 200K.
If both of the above tests are positive then we can conclude
that the LDR is healthy.

52 IT & ITES : ICTSM - Exercise 1.2.11

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.12

Measuring AC and DC wave parameters using CRO

Objectives: At the end of this exercise you shall be able to
• set controls of CRO for waveform parameters measurement
• connect AF signal generator to CRO input
• measure amplitude and frequency of the waveforms using CRO.

Requirements

Tools/Equipments/Instruments 1:10 probe - 1 No./ batch.

• AF signal generator - 1 No./ batch.
• Oscilloscope 20 MHz - 1 No./ batch.
• CRO probes1:1 probe - 1 No./ batch.

PROCEDURE

1 Without feeding any signal to the input of CRO, adjust

the CRO controls such that a fairly bright, well focussed
straight beam (called raster) is seen on the CRO screen
as shown in Fig 1.

2 Get the adjusted raster and controls set check it by

your instructor.
3 As demonstrated by your instructor connect the output
of the AF signal generator to one of the channel input of
the oscilloscope using a 1:1 CRO probe. Get the
connections checked by your instructor.

While making connections ensure that the AF

generator is powered OFF.

4 Ask your instructor to set the output level and frequency

of the AF signal generator to some value. 8 Calculate and record the frequency of the AF signal and
5 Adjust CRO controls such that one or two cycles of the rms value of the signal.
the waveform is seen on the CRO screen as shown 9 Get the work checked by your instructor.
in Fig 2.
10 Repeat steps 4 to 9 for atleast five different settings of
6 Record the volts/div and time/div setting made. Record the AF signal generator output.
the number of divisions occupied by the signal in volt/
div axis (Y-axis) and time/div axis (X-axis) on the Try one or two measurements using 1:10 probe.
graticule scale of the CRO screen.
7 Calculate and record the peak, peak-to-peak and time
period of the waveform seen.

53
54
Record Sheet for Exercise 1.2.12

1 Instructor’s remarks on;

a) Initial CRO raster and control settings
Very good Good Satisfactory Poor/Redo

b) Connections made between AF signal generator output-to-CRO input.

2 Table - 1
Sl. Set Set position Number of Number of No. of time Positive Negative Peak to Time Frequency RMS value
No. position of Time/div divisions divisions divisions occupied peak value peak value peak value Period in Hz Vrms in
of occupied in occupied in on x-axis for in volts in volts in volts (T) volts
Volt/div +ve y-axis -ve y-axis one cycle in sec.

IT & ITES : ICTSM - Exercise 1.2.12

4

(Trainee) (Instructor)
IT & ITES
ICTSM - Basic Electrical Exercise 1.2.13

Identify, find the value of inductors & measure inductive reactance

Objectives: At the end of this exercise you shall be able to
• identify different types of Inductors by their appearance
• check the physical and electrical condition of inductors
• measure value of inductance using RLC bridge and Digital LCR meter.
• measure the impedance Z of a coil at different frequencies
• calculate value of inductive reactance XL at different frequencies
• calculate power factor Cos ø
• calculate inductance L of a given inductor
• calculate current lagging angle ø.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Assorted types and values of Inductors, - 16 Nos.
• LCR bridge of any type - 1 No./batch • Hook up wires - as reqd.
• Digital LCR meter - 1 No./batch • Inductor coil of 1500 turns of 36 SWG - 1 No.
• AC milliameter, 0-300mA - 1 No./batch • Inductor - 2 Nos.
• AF signal generator - 1 No./batch
• Regulated DC PSU, 0-30V, 1A - 1 No./batch

PROCEDURE

TASK 1: Identify and Measure value of Inductance

1 Take any one inductor from the given assorted lot.

Compare it’s physical appearance with inductors shown Since training institutes have different types of
in Chart 2 of lesson 1.2.13. Identify the type name, LCR bridges, and as each bridge has its own
symbol and record it in Table 1 of record sheet. specific type of controls/switches/jumpers,
procedure for setting up of bridge and
2 Check for any of the physical defect listed below in the measurement are not given here.
chosen inductor. Record the observed defect(s) if any.
A) Conductor broken in the winding 6 Take any one of the inductor used in previous steps.
Connect the chosen inductor across the test terminals
B) Coating on copper wire peeled off of the LCR bridge.
C) Core cracked
If necessary solder hook up wires at the
D) Former broken terminals for ease of connecting the inductor
3 Using a multimeter in low resistance range, measure across the test terminals. Use minimum lead
and record the resistance across inductor terminals. length for connection as lead length will add
up inductance value.
If the resistance measured is very high or if the
meter shown open circuit, the inductor may be 7 Balance the bridge as demonstrated by your instructor
defective; in such a case, consult your instructor. and show it to your instructor before taking readings.
8 Record the measured value of the inductor in Table 1 of
4 Repeat steps 1 to 3 for atleast 5 different types of record sheet. Remove the inductor connected to the
inductors and get your work checked by Instructor. LCR bridge.
5 As demonstrated by your instructor, carry out neces- 9 Set the given Digital LCR meter controls for measuring
sary settings on the given LCR bridge to measure inductance. Connect the same inductor used in steps
Inductance of an unknown inductor. Use internal 1KHz 6,7&8 across the Digital LCR meter. Record the induct-
AC source of the bridge for inductance measurement. ance value shown by the digital meter.

55
 11 Repeat steps above and measure inductance of atleast
Procedure for Digital LCR meter set-up and
five different types of inductors and get your work
measurement is not given due to various
checked by your instructor.
varieties of Digital Meters used in different
training institutes.

10 Compare the measured value of the inductor using LCR

bridge and Digital LCR meter. Record the difference in
Table 1. Discuss reasons for difference in reading (if
any) with your instructor.

TASK 2: Measuer value of L,Z,XL and Cos ∅ of a given inductor

1 Measure and record the internal DC resistance of the (i) DC resistance (ohmic resistance) R of the coil
given coil using multimeter.
(ii) Impedance Z of the coil
2 Measure the inductance (L) of the coil using digital RLC
(iii) Inductive reactance XL of the coil
meter and record its value in record sheet.
(iv) Inductance L of the coil
3 Connect the coil across a 6V DC supply. Measure and
record the DC current drawn by the coil in Table 1 of (v) Power factor Cosø of the coil
record sheet. (vi) Angle by which the current lags the voltage.
4 Connect the coil across the output terminals of a AF 7 Compare the value of L measured using digital RLC
signal generator. Set signal generator output to 6 Vrms, meter in step 2 and that calculated at step 6.
at 1KHz. Measure and record the AC current drawn by
the coil. If there is large difference in the value of L
For more accurate measurement of AC currents at high found by the two methods, consult your
frequencies, special meters are available. However at instructor.
this stage, trainees can measure these high frequency
currents using the multimeter itself. 8 Write the value of L of the coil on a small piece of paper
and paste it on the solenoid.
5 Change the output frequency of the signal generator in
steps as shown in Table 1, retaining the output level at 9 Get your work checked by your instructor.
6V. Measure and record the AC current drawn by the 10 Repeat steps 1 to 9 for at least two other inductor coils
coil at each frequency setting. given to you by your instructor.
6 From the recorded readings in record sheet, calculate
and record the following;

56 IT & ITES : ICTSM - Exercise 1.2.13

 Record Sheet for Exercise 1.2.13

Table - 1
Label Type/name Symbol Physical Resistance Inductance value Difference
No. of defect(s) across using using in reading
inductor noticed coil LCR digital between
terminals bridge meter bridge and
digital meter
(if any)

IT & ITES : ICTSM - Exercise 1.2.13 57

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.14

Determine Mutual inductance (M) and Coefficient of coupling(k) of Coils

Objectives: At the end of this exercise you shall be able to
• measure the total inductance of coils
(i) in series aiding
(ii) in series opposing
• measure XL of coils in series
• determine mutual inductance M between coils
(i) placed far apart on a rod
(ii) placed close to each other on a rod
(iii) placed on the arms of a closed U core
• determine the coefficient of coupling (k) between coils.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Inductor coils - 2 Nos.
• A.C milliammeter 0-300mA - 1 No./batch.
• A.F signal generator - 1 No./batch.
• Soft iron rod, round/square 10mm,
length 150mm - 1 No./batch.
• U & l core of soft iron - 1 set/batch.
(Refer Fig 4 for dimensions)

PROCEDURE
1 Connect the given two inductors L1 and L2 in series.
Connect it to 6volts DC power supply. Measure DC
current by the coils. Calculate and record the total
ohmic resistance (RT) of the coils in series.
2 Insert the coils over a round soft iron rod and position
them as shown in Fig 1. Connect the two inductors in
series and apply 6 volts, 1KHz, ac to the series coils
using a signal generator as shown in Fig 1.
The position of the inductor coils is important. Therefore
position the coils at the ends of the iron rod as shown
in Fig 1.
3 Measure and record voltage across the coils VLT and
circuit current I in Table 1 of record sheet.
4 Move the coils close to each other as shown in Fig 2.
Measure and record the voltage across coils VLT and
circuit current I in Table 1.
5 Change the connections between the coils such that
the coils are in series but with opposing field as shown
in Fig 3. Measure and record the voltage across the
coils VLT and circuit current I.

Note: Keep the position of coils 1 and 2 close to

each other as in Fig 2.

6 With the coils connected in series opposing, push the

coils to the extreme position of the soft iron rod as in
Fig 1. Measure and record the voltage across the coil
VLT and circuit current I.
58
7 Make a set-up as shown in Fig 4. Connect the coils in
series aiding. Measure and record the voltage across 9 From the recorded values of voltage across inductors
the inductor VLT and circuit current I. (VLT) and currents calculate values of XL, L, M and K and
record in Table 1 of record sheet.
8 For the set-up made as in Fig 4 change the coil
connections such that the coils are in series-opposing. 10 Get your work checked by your instructor.
Measure and record the voltage across the inductor VLT
and circuit conductor I.

Record Sheet for Exercise 1.2.14

1 Total ohmic resistance (DC resistance) of coils L and L in series: _____________________

1 2
2 Table - 1
VLT X LT
X LT = X T =
Connection of Frequency Voltage Current I 2πf For series aiding K
L + L2
coils L and L
1 2
f across through M = 1 M
coils coils I (X =X +X ) (L = L + L ) 4 k=
LT L1 L2 T 1 2 L1. L 2
V For series-opposing
LT L1 – L 2
M =
4

L & L in series
1 2
fields aiding.
Coils placed far
apart on an iron rod

L & L in series
1 2
fields aiding.
Coils placed
close on an iron rod

L & L in series
1 2
fields-oppsoing.
Coils placed
close on an iron rod

L & L in series
1 2
fields-opposing.
Coils placed far
apart on an iron rod

L & L in series
1 2
fields aiding.
Coils on the two
arms of a closed
U core
L & L in series
1 2
field opposing
Coils on the two
arms of closed U
core.

IT & ITES : ICTSM - Exercise 1.2.14 59

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.15

Find Transformation ratio and conduct OC , SC test for Transformer

Objectives: At the end of this exercise you shall be able to
• identify the type of given transformer
• identify primary and secondary windings
• connect transformer to mains and measure voltages and currents
• calculate voltage and current transformation ratios
• calculate power consumed in primary & secondary windings
• find the approximate transformer loss
• find the iron loss and copper loss of the transformer
• find the efficiency of the transformer.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Mains transformer 240:12V, 3 amps - 1 No.
• AC milliammeter, 0-500 mA - 1 No./batch. • Resistor, 220Ω, 1Ω, carbon - 1 No.
• AC ammeter, 0-5A - 2 Nos./batch. • Resistor, 100Ω, 2Ω, carbon - 1 No.
• Wattmeter 250V, 1A, 250 watts - 1 No./batch. • Two-core mains power cord with - 1 No.
2 pin plug(End product of previous exercise)
• Patch cords - as reqd.

PROCEDURE

TASK 1: Measure the Transformation ratio of Transformer

1 For the given transformer, from its appearance, shape

Ideally when no power is consumed in the
of core etc., identify the type of the transformer and
secondary, primary should also not consume
record details in record sheet. Get it checked by your
power. However, for transformer losses the
instructor.
primary will consume power.
2 As demonstrated by your instructor identify the
primary and secondary winding terminals or terminal 7 Solder two patch cords (plain end-crocodile clip end) to
wires of the transformer. Write a sketch of the the secondary winding terminals. Clip a 220W, 1watt
transformer windings and write the colour code of the resistor across the secondary.
primary and secondary windings in record sheet. Get
Ensure that the AC mains connection to the
it checked by your instructor.
transformer is disconnected before soldering.
3 Measure and record the DC resistance of the primary
and secondary windings using multimeter. 8 With 220W, 1watt load across secondary, measure
and record Vpri, Vsec, Ipri and Isec.
4 Solder the 2 core mains power cord to the primary
winding terminals of the transformer. 9 From the recorded readings in step 8, calculate and
record the voltage-transformation ratio (Vpri/Vsec) and
5 Connect primary winding to AC mains supply. Meas-
current transformation ratio (Isec/Ipri).
ure and record AC mains supply voltage across pri-
mary (Vpri), primary current (Ipri) and no-load secondary 10 Repeat steps 8 and 9 by changing the secondary load
voltage. resistance to 100Ω, 2watts.
11 From the recorded readings calculate and record the
The secondary voltage is referred to as no-
energy consumed by the primary and secondary in all
load secondary voltage because, there is no
cases.
load connected across the secondary winding
of the transformer. 12 From the tabulated results check to confirm the following;

6 From the recorded readings calculate and record the Vpri I sec
(i) = is same with 220Ω and 100Ω load.
primary to secondary voltage transformation ratio and Vsec I pri
the power consumed by the primary winding of the
transformer. (ii) Power consumed in primary > power consumed
in secondary.
60
 13 Get your work checked by your instructor.
Note: Consult your instructor for clarifications
if any.

TASK 2: Find Iron loss of the given transformer [This test is popularly known as OPEN CIRCUIT or OC TEST]

1 Record the specifications/rating of the given transformer

in record sheet.
2 Measure and record the ohmic resistance of primary
and secondary windings in record sheet.
3 Connect the test set-up for OC-test as shown in Fig 1.
Get it checked by your instructor.
4 Switch ON mains. Measure and record primary power
(WI), primary voltage(Vp), primary current (IP).
5 From the recorded values, calculate and record the
transformation ratio K of the transformer and power
factor cosø in table 1.
6 Get your work checked by your instructor.

TASK 3 : Find Copper loss of the given transformer [This test is popularly known as SHORT CIRCUIT or SC test]

1 Connnect the test set-up for SC-test as shown in Fig 4 Increase the output voltage of VARIAC till 100%
2 and get it checked by your instructor. rated secondary current flows through the second-
ary winding.
Make sure that the auto-transformer (VARIAC)
is at zero volt output position otherwise the 5 Record readings of Wc, IP, VP and IS in Table 2.
transformer under test may get damaged 6 Switch OFF mains and disconnect the set-up.
permanently.
7 Calculate and record the current transformation ratio
2 Slowly increase the output of VARIAC till 50% of rated using the recorded values of IP and IS.
secondary current(IS) flows in the secondary winding. 8 From the readings recorded in Table 1 and 2. Calculate
and record
Rated secondary current will flow at a very
low primary voltage (Vp) itself. Hence take care (i) Total transformer losses
not to increase the output of auto transformer (ii) Efficiency of the transformer at 50% of rated load
abruptly. This will damage the transformer
permanently. (iii) Efficiency of the transformer at 100% of rated
load
3 Record readings of Wc, IP, VP and IS in Table 2. 9 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.2.15 61

 Record Sheet for Exercise 1.2.15

1. The transformer under test is (Choose the correct type from each category),
Note: Tick item (vi) while doing the exercise
(i) Air-core/ferrite-core/iron-core transformer

(ii) Core type/sheel type/ring type transformer

(iii) Mains frequency/audio frequency/high frequency transformer

(iv) Single phase/poly phase transformer

(v) Voltage/current transformer

(vi) Step-up/step-down/isolation transformer

2. Sketch the transformer windings and indicate wire colours

3. a Resistance of primary winding (N ) : _______________________ W

p
b Resistance of secondary winding (N ) : _______________________ W
s
4.
Load across Primary voltage Secondary Primary Secondary Transformation Power
secondary (V ) voltage current current ratios consumed
pri
(V ) (I ) (I ) V I Primary Secondary
sec pri sec pri sec

V I pri
sec

NO LOAD

220W

100W

5. Power loss in the transformer under no-load condition: ____________________

62 IT & ITES : ICTSM - Exercise 1.2.15

Record sheet for OC and SC tests

1. Transformer specifications:

(i) Type of transformer : Single phase/Three phase

(ii) Rated primary voltage : Frequency :

(iii) Rated secondary voltage : volts

(iv) Rated secondary current : Amps

(v) VA rating of transformer : VA

2.
(i) Resistance of primary winding : Ohms

(ii) Resistance of secondary winding : Ohms

3. Table - 1
(Results of OC-test)
Transformation ratio K Power factor
V I Iron loss V
P P S
Vs W
W I K = Cos φ = I

Vp Vp . I p

Rated
primary
Voltage
(230 V )
rms

4. Table - 2
(Results of SC-test)
Secondary winding Primary winding Copper loss Transformation ratio Total transformer losses
current current Ip W =W +W
I C
IS IP WC (W)
Is

[50% of rated current]

Amps

[100% of rated current]

Amps

5 Efficiency(h) of the transformer

(i) At 50% of rated load:
(ii) At 100% of rated load:

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.2.15 63

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.16

Testing transformers Voltage regulation and Efficiency

Objectives: At the end of this exercise you shall be able to
• measure tranformer regulation at resistive and reactive loads
• measure the efficiency of transformer with resistive and reactiive loads.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Mains transformer 240:12V, 3A
• AC ammeter 0-5 amp - 1 No./batch. (used in Ex.No.1.2.15) - 1 No.
• AC milliammeter, 0-500 mA - 1 No./batch. • DPST switch (5 Amps rating) - 1 No.
• Wattmeter, 100 Watts - 1 No./batch. • Patch cords - as reqd.
• PowerFactor meter 0.5lag-1-0.5lead - 1 No./batch.
• Rheostat 100Ω, 50 watts - 1 No./batch.
• Tube light choke 40 watts (inductor) - 1 No./batch.

PROCEDURE

TASK 1: Finding transformer regulation and efficiency with resistive loads

1 Connect the test set-up as shown in Fig 1 and get it 6 Adjust rheostat such that different % of rated current as
checked by your instructor. listed in Table 2 of record sheet flows in transformer
2 With SW-1 in OFF condition (NO-LOAD to secondary). secondary. At each setting record the corresponding
Switch ON mains supply. meter readings in Table 1.

3 Record readings of Ip, Vp, Cosø and Vs in Table 1 of 7 Reduce secondary current to near zero and switch OFF
record sheet. SW-1 and AC mains supply.

4 Set the Rheostat to maximum resistance position and 8 From the reading recorded in Table 1, calculate and
put SW-1 to ON. record the regulation and efficiency of the transformer at
different resistive loads.
Now the secondary is connected to a resistance load.
9 Get your work checked by your instructor.
5 Adjust Rheostat such that 25% of rated transformer
current flows in secondary. Record all the meter readings
in Table 1.

64
TASK 2 : Finding transformer regulation and efficiency with inductive loads

1 Remove the Rheostat connected across the secondary.

Connect a tube light choke or any other inductive load
as shown in Fig 2.
2 Switch ON mains supply. Put SW-1 to ON. Record
readings of all the meters in Table 2.
Now the secondary has inductive load.
3 Switch OFF SW1 and AC mains supply.
4 From the recorded readings in Table 2, calculate the
regulation and efficiency of the transformer with 5 Get your work checked by your instructor.
inductive load.

Record Sheet for Exercise 1.2.16

1 TABLE 1
(Resistive Load)
Power %Regulation %Efficiency
Load V I P.F W = V I Cosφ φ V I W Ws
VNL – VL
P P

φ)
(Cosφ P P P
(at primary)
S S S
x100% η = x 100%
VL Wp

Open (V )
NL
or
No-load

25% of
rated
load

50% of
rated
load

75% of
rated
load

100% of
rated
load

NOTE:V = Secondary voltage at No-load and V = Secondary voltage at any % of Full load.
NL L
2 TABLE 2 (Inductive Load)
Power %Regulation %Efficiency
Load V P I P P.F φ V
WP = VP IP Cosφ S
I S
W
S

φ)
(Cosφ VNL – VL Ws
(at primary) x100% η = x 100%
VL Wp

Choke
as
load
(inductive)

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.2.16 65

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.17

Winding low VA rating mains transformer

Objectives: At the end of this exercise you shall be able to
• wind a low VA transformer given the specifications using a transformer winding machine
• test the wound transformer for its rating and efficiency.

Requirements

Tools/Equipments/Instruments Note 2 : The specifications of the transformer

to be made by trainees is left to the choice
• Trainees kit
of the instructor. However a sample design
• Transformer handwinding - 1 No./batch.
data of a transformer is given below: the
machine
instructor may use this data if he so wish.
• Ball pein hammer, 0.5 kg - 1 No./batch.
• Spanner set (5mm to 20mm) - 1 No./batch. Specifications:
Materials/Components
1 Rated primary voltage: 240V,
• Bobbin stampings (see note-1) - 1 set./batch. Rated secondary voltage : 6volts,
• Super enameled copper wire Rated primary frequency : 50Hz,
(see note-2) - as reqd. Rated secondary current : 2.5Amps,
• Air dry varnish - as reqd. Volt-ampere rating : 15VA,
• Rosin cored solder - 10 cm/batch. Assumed efficiency : 80%
• Terminal lugs - 5 Nos/batch.
2 Core area : 20 x 21mm
Bobbin dimensions :
Note 1: Breadth : 20.6mm,
Height: 21mm
1 The bobbin dimensions depends on the Length : 26.7 mm,
transformer rating. This will be given by your Total height of flange : 42.7 mm
instructor.
3 Wire size and no. of turns
2 The gauge and length of wires required Primary: 3200 turns of 0.16mm or 37 SWG
depends on transformer voltage and current Secondary: 88 turns of 1.00mm or 19 SWG
rating. This will be indicated by your instructor.
4 EI stamping: EI 60/20 type 55 numbers having
thickness of 0.35 mm each.

Detailed winding procedure is not given in this exercise to the trainees as different training centers use
different type of winding machines. Hence, the instructor shall demonstrate winding of a transformer
preferably in stages listed below;

1 Fixing spares and making the bobbin.

2 Fixing the bobbin on wooden block and clamping it on the winding machine.
3 Feed and transverse feed adjustments based on the gauge of selected wire.
4 Winding and insulating windings.
5 Stacking EI laminations and clamping the assembly
6 Varnishing the transformer.

PROCEDURE
1 Obtain the specifications/rating of the transformer to be 3 Get the assembled bobbin checked by your instructor.
wound from your instructor and record details in record
sheet. 4 Fit the bobbin on a wooden block or on to a suitable
mandrel of the winding machine. Clamp it to the winding
2 Collect the bobbin components. Assemble the bobbin machine as demonstrated by your instructor.
components as demonstrated by your instructor.
5 Get the clamped mandrel/wooden block checked by
Fig 1 shows the spares of bobbin and its final your instructor.
assembled shape.
66
6 Carryout necessary feed adjustments and counter
adjustments as demonstrated by your instructor.
7 Wind the HV/primary winding layer by layer as
demonstrated by your instructor.
8 After completing specified number of turns of the
primary winding, wrap it with insulator as demonstrated
and get it checked by your instructor.
9 Select specified gauge enameled copper wire for LV/
secondary winding and carryout necessary feed
adjustments. Get it checked by your instructor.
10 Wind the secondary winding layer by layer. After
completing winding required number of turns, insulate
the secondary by wrapping it using suitable insulating
tape/paper.
11 Remove the transformer coil from winding machine and
wooden block. Solder the primary and secondary
terminals on the terminals provided on the bobbin
flange.
12 Stack the E & I core laminations as shown in Fig 2 and
as demonstrated by your instructor. After inserting all
the laminations get it checked by your instructor.
13 Fix the clamp(s) and fixing bolt if any on the assembly.
Get it checked by your instructor.
14 Varnish the transformer as demonstrated by your
instructor. Allow it to dry.
15 Get your work checked by your instructor.
16 Test the wound transformer as done in previous exercises
and record the test data in record sheet.

Space for recording

additional practical tips given by your instructor:

IT & ITES : ICTSM - Exercise 1.2.17 67

 Record Sheet for Exercise 1.2.17

1
i Rated primary voltage :
ii Rated primary supply frequency :
iii Rated secondary voltage :
iv Rated volt-ampere :

2 Bobbin dimensions :
Breadth :
Height :
Length :
Total flange height :

3 Wire size and number of turns :

Primary : ________________ Turns of _________________ SWG
Secondary : ________________ Turns of _________________ SWG

4 Details of stampings :
Type :
Number of stampings :

5 Instructor remarks on the transformer wound by the trainee/trainees group:

6 Test results:
OC - Test SC - Test
V V
P P
V I
S P
I I
P S
W W
I c
Cosø Cosø

Voltage transformation ratio

Current transformation ratio

Total losses (Cu + Iron)

Efficiency of transformer
At 50% rated load
At 100% rated load

(Trainee) (Instructor)

68 IT & ITES : ICTSM - Exercise 1.2.17

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.18

Identify and test fixed value capacitors

Objectives: At the end of this exercise you shall be able to
• identify the different types of fixed value capacitors by their appearance
• check the physical condition of fixed value capacitors
• determine the capacitance value by colour code/other codes.
• carry out a quick test on capacitors using ohmmeter/ multimeter
• carry out charge holding test on capacitors.

Requirements

Tools/Equipments/Instruments Materials/Components
• Regulated Power supply, 0-12V, 1A - 1 No. • Assorted types of fixed capacitors - 20 Nos.
/16 trainees.
• Patch cords - as reqd.

PROCEDURE

TASK 1: Identify & find value of fixed value capacitors

1 Pick any one capacitor from the lot. Identify the type of 3 From the physical condition of the capacitor recorded,
capacitor by comparing its physical appearance with give your conclusion about the usability of the capacitor
the those shown in Chart 3 of lesson 1.2.18. Record the in Table 1.
identified capacitor type name in Table 1 of the record
sheet. 4 Refer colour code/typographic code chart for capaci-
tors given in tables at appendix D. Find and record the
2 In the chosen capacitor, check for any of the physical Capacitance value, Tolerance, Voltage rating(DCWV)
damages listed below. Record the defect(s) found in and Temperature coefficient of the capacitor in Table 1
Table 1. of the record sheet.
(a) Terminal(s): loose/broken/weak points. 5 Repeat steps 1 to 4 for atleast ten more different
(b) Body: charred/burnt/melted/bulged. types of given capacitors.

(c) Body: punctured/broken/cracked. 6 Get the work checked up by the instructor.

(d) Sticky liquid oozed out.

(e) Value and rating not visible.

TASK 2: Quick test using ohmmeter/multimeter

1 Take a capacitor, identify and record the type of

capacitor, marked/coded capacitance value and voltage
rating in Table 2 of the record sheet.
2 Using a patch cord with crocodile clips, short the
terminals of the capacitors for 1 to 2 seconds as shown
in Fig 1a.
3 Set the multimeter/ohmmeter to available highest ohms
range. (generally x1000Ω range)

Shorting capacitor terminals discharges stored

charges, if any, in the capacitor. While
discharging high voltage rating capacitors as
shown in Fig 1b use a small resistor in series
with the shorting cord and do not touch the
metallic parts of the clip.
69
4 Connect/hold one of the meter probe to one of the
If the observation was not clear, discharge the
terminals of the capacitor.
capacitor as shown in Fig 1 and redo steps 4
5 Touch the other meter probe to the other terminal of the and 5.
capacitor, and simultaneously observe the meter pointer
movement. 7 Repeat steps 1 to 6 for atleast ten more
different types of given capacitors.
6 From the observed meter pointer movement, refer the
table given below and identify the condition of the 8 Get your work checked by your instructor.
capacitor under test. Record the identified condition in
Table 2 of record sheet.
NOTE:
TABLE 1 To observe deflection more clearly, use lower
range ohms for high value capacitors and higher
Meter deflection Probable defect Usability range for small value capacitors.

Initially pointer moves NO DEFECTS FIT 2 Normal resistance values shown by different types
quickly towards zero [Capacitors in of capacitors while testing condition using ohm-
ohms and then moves good condition] meter.
slowly towards high Electrolytic Ω minimum
: 500 KΩ
resistance/infinity and
settles there.
Paper, Mica,
Pointer goes to zero SHORTED UNFIT Ceramic & Polyster Ω minimum
: 500 MΩ
ohms and remains there. CAPACITOR
3 If you are testing an electrolytic capacitor the
Pointer does not move OPEN UNFIT defect OPEN CAPACITOR is true. If you are testing
at all from infinite ohms CAPACITOR a non-electrolytic capacitor, since the charging
position. Not even (See Note-3) action cannot be seen clearly. This observation as
slightest deflection of MAY BE OPEN. This can be confirmed or otherwise
pointer observed. (See in charge-holding test at Task 3.
Note 1)

Initially pointer moves LEAKY UNFIT

towards zero ohms and CAPACITOR
quickly moves towards
high resistance. But the
final resistance reading
is less than normal.
(See Note 2)

TASK 3 : Charging test using DC supply and voltmeter

1 Mark the test setup as shown in Fig 2a. 5 When the meter pointer becomes stable, record the
2 Take any one of the capacitors checked in Task 2 and voltmeter reading in Table 2 of record sheet.
discharge the capacitor by shorting its terminals.
With SW ON, if the meter shows 0 volts reading
3 Connect the capacitor across points A and B of the test even after 5 to 10 seconds record the reading of
set up as shown in Fig 2b. voltmeter in Table 1 and skip steps 6 and 7.
4 Switch ON SW such that the capacitor gets charged
6 Switch OFF SW. Wait for 10 seconds. After 10 sec-
upto dc supply voltage.
onds record the voltmeter reading in Table 2.
Observe the rising voltmeter reading when the The voltage across the capacitor (shown on voltmeter)
capacitor is charging. When the capacitor gets starts decreasing soon after SW is put OFF. If 10
charged to DC supply voltage, the voltmeter seconds is found too large, take reading after 2 or 3
reading becomes steady. seconds or as found suitable and record it in Table 2 of
record sheet.

70 IT & ITES : ICTSM - Exercise 1.2.18

 7 Take out the capacitor from the test set up. Dis-
charge the capacitor by shorting the terminals of the
capacitor.
8 Repeat steps 2 to 7 for the remaining capacitors.
9 From the recorded readings, conclude the usability of
the capacitors and record in Table 2.
10 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.2.18 71

72
Record Sheet for Exercise 1.2.18

Task 1: Table - 1
Label No. Type of capacitor Lead Physical defect(s) Usability Capacitance Tolerance Rated Temperature
Type (Fit/Unfit) value voltage coefficient

IT & ITES : ICTSM - Exercise 1.2.18

 TASK 2: Table - 2
Label Type of Capacitance Tolerance Voltage Measured Measured Difference Difference
No. capacitor value rating capacitance value capacitance value of measured of identified & ave.
DCWV using RLC Bridge using digital LCR meter values measured value

IT & ITES : ICTSM - Exercise 1.2.18

(Trainee) (Instructor)

73
IT & ITES
ICTSM - Basic Electrical Exercise 1.2.19

Measure C, find XC and Z of a RC circuit

Objectives: At the end of this exercise you shall be able to
• measure the capacitance of a capacitor using a RLC bridge
• measure capacitance of a capacitor using digital capacitance/RLC meter
• find the capacitive reactance of a capacitor
• measure the impedance of a RC circuit
• find the capacitance of an unknown capacitor.

Requirements

Tools/Equipments/Instruments Materials/Components
• LCR bridge - 1 No./batch. • Assorted values and types of fixed
• AC Milliammeter, 0-10mA - 1 No. value capacitors - 20 Nos.
• AF Signal Generator/Function • Patch cords/hook-up wires - as reqd.
generator • Lug board - 1 No.
• Digital LCR meter - 1 No./batch. • Capacitors 10μF, 25V,Non-polar. - 1 No.
• Capacitor of unknown value,
DCWV>12V,Non-polar. - 2 Nos.
• Resistor, 1KW, 1/4W - 1 No.
• S.P.S.T switch (any type) - 1 No.
• Patch cords - as reqd.

Note: In task 1, capacitor with its printed value covered will be given by your instructor for you to find its
capacitance value from this exercise.

PROCEDURE

TASK 1: Measure capacitance value using LCR meter

1 Pick any one capacitor from the given lot. Find and 4 Set up the given digital capacitance/LCR meter for
record its type, capacitance value, DCWV and tolerance capacitance measurement. Connect the capacitor
in Table 1 of record sheet. across the meter terminals for measurement.
2 Carry out the necessary settings on the given RLC The procedure for instrument set up and measurement
bridge to measure the capacitance of the chosen is not given because of the variety of digital meters used
capacitor. Use the internal 1KHz ac source of the bridge in different training institutes. This will to be demonstrated
for capacitance measurement. by the instructor before starting this exercise.
Since different training institutes have different types of 5 Measure and record the value of the capacitance in
RLC bridges and as each bridge has its own type of Table 1 of record sheet.
controls/switches/jumpers, the procedure for setting 6 Compare the value of capacitor measured using RLC
up of the bridge and measurement is not given here. bridge with that measured using digital capacitance
This will be demonstrated by the instructor before meter. Record the difference in record sheet.
starting this exercise.
7 Compare the value of capacitance found from colour
3 Connect the capacitor across the test terminals of the code with the average of the measured capacitor value.
bridge. Balance the bridge as demonstrated by your Record the difference in record sheet.
instructor and show it to your instructor before taking
readings. Record the measured value of the capacitor 8 Repeat steps 3 to 7 for atleast ten different type and
in Table 1. Remove the capacitor connected at the test value capacitors.
terminals. 9 Get your work checked by your instructor.

74
TASK 2: Measure capacitive reactance and impedance of RC circuit

1 Measure and record values of R and C in Table 2 of

record sheet.
2 Connect the given resistance R and capacitance C in
series and make the test set-up as shown in Fig 1.
3 Set the output of signal generator to sine wave, 12
Vrms, at 1 KHz.
Use a CRO to set frequency exactly to 1 KHz if
necessary.
4 For the set frequency of 1 KHz, calculate and record
theoritical values of XC and Z using formulae;

1 2 2
XC = ohms Z = R + XC
2πfC
5 Put SW to ON. Record the output voltage(VS) of the
signal generator in Table 2 of record sheet. 9 Change the output frequency of the signal generator to
frequencies given at Sl.Nos. 2 and 3 of Table 2. At each
The output voltage level of the signal generator may
setting repeat steps 6 to 8.
come down when connected to the external circuit due
to impedance mismatch. Hence adjust output level of 10 Take one of the given capacitor of unknown value.
signal generator after switching on SW. Connect it in series with the test setup in place of the
10μF capacitor.
6 Measure and record, the circuit current(I), voltage drop
across the capacitor(VC) and voltage drop across the 11 Repeat steps 3,5,6 and 7 to find the capacitance of the
resistor(VR) in Table 2 of record sheet. unknown capacitor. Record value in record sheet.
Unlike in DC series circuits, VC + VR will not be equal 12 Check the capacitance of the capacitor using digital
to VS because VC and VR are out-of-phase. LCR meter. Compare with the value found at step 11 and
record the difference.
7 From the recorded values of VS, VC, VR and I, calculate
and record the values of XC, C and Z using the formulae, 13 Repeat steps 10, 11 and 12 for the other given capacitor
of unknown value.
VC Vs 1
XC = , Z = and C = 14 Get your work checked by your instructor.
IC I 2πfX C

Note: In this case IC = I, because it is a series

circuit.

8 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.2.19 75

76
Record Sheet for Exercise 1.2.19

Table - 1
Label Type of Capacitance Tolerance Voltage Measured Measured Difference Difference
No. capacitor value rating capacitance value capacitance value of measured of identified & ave.
DCWV using LCR Bridge using digital LCR meter values measured value

IT & ITES : ICTSM - Exercise 1.2.19

 Task 2: Table - 2
Serial Measured Measured Set frequency Calculated Set level Measured values Calculated values Difference in
Number value of value of f in Hertz Theoritical of V value of C
S(rms)
resistance capacitor values of

R C X Z I V V X Z C
C C R C

1 1 KHz

2 10 KHz

ohms
µFarads
3 100 KHz

4 1 KHz

IT & ITES : ICTSM - Exercise 1.2.19

5 1 KHz

6 1 KHz

(Trainee) (Instructor)

127
77
IT & ITES
ICTSM - Basic Electrical Exercise 1.2.20

Characteristics of Series & Parallel Resonance Circuit

Objectives: At the end of this exercise you shall be able to
• determine the resonance frequency of a given LC series and LC parallel circuit
• determine the circuit current at different frequencies
• plot a graph of frequency versus circuit current
• find the value of an unknown L using LC series resonance
• find the values of an unknown C using LC parallel resonance.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit - 1 No. • General purpose Lug board - 1 No.
• CRO, 20 MHz - 1 No./batch. • Capacitor 0.1 μF - 1 No.
• Function generator - 1 No./batch. • Inductor coil, around 40mH - 1 No.
• Unknown value Inductor - 1No.
• LED with holder - 1 No.
• Hook-up wires - as reqd.

PROCEDURE

TASK 1: Finding Resonance frequency and circuit current

1 Measure and record the inductance of the coil. 5 Increase the frequency gradually and record the
2 Solder the components as shown Fig 1 to obtain a resonance frequency f at which the circuit current
r
simple series resonance circuit. Connect instruments becomes maximum(LED glows brightly).
as shown in Fig 1. This is the resonance frequency of the series resonance
The LED in the circuit is to get a visual indication of the circuit because at series resonance, current I through the
current through the circuit at different frequencies. LC circuit will be maximum.
6 Compare and record the difference in the resonance
Fig 1 frequency calculated at step 3 and that measured in
step 5.
C = 0.1μ F L = 40mH

LED
7 Vary the input frequency in steps of 500 Hz around the
SIG resonance frequency as indicated in O&T sheet and in
GEN
each step record the value of circuit current.
8 From the recorded readings of current in step 6, plot a
0-30 graph of frequency versus current and mark the
mA resonance frequency of the LC series circuit.
9 Get the working of the circuit, recorded readings and the
3 Knowing the values of L and C, calculate and record the graph checked by your instructor.
resonance frequency of the series resonance circuit.
4 Set the output of the signal generator to 10V and
rms
frequency to 1KHz. Record the current, I through the
circuit.
LED may not be glow or may be very dim, because the set
frequency of 1 KHz may not be the resonance frequency of
the circuit.

78
TASK 2: Finding Inductance value of an unknown Inductor

3 Knowing the value of C and f , calculate and record the

Note: You may use the solenoid coil used by r
another trainee in task-1 as an unknown value inductance value of the unknown inductor using the
inductor. formula given below;
At resonance, X = X
1 Connect the unknown value inductor in place of the coil L C
connected in the LC series circuit at Fig 1.
1 1
or 2πfr L = 2πf C or L = 2 2
2 Set the output level of the of signal generator to 10V . r 4π fr C
rms
Increase the output frequency gradually and record the
resonance frequency f at which the circuit current 4 From the found value of L recalculate the resonance
r frequency f to reconfirm the found value of L.
becomes maximum(LED glows brightly). r
This is the resonance frequency of the series resonance
circuit formed by the unknown value of C and unknown
value of L.

TASK 3: Finding Parallel resonance frequency and circuit current

1 Measure and record the inductance of the coil. 5 Increase the frequency gradually and record the reso-
2 Solder the components as shown Fig 2 to obtain a nance frequency f at which the circuit current becomes
r
simple parallel resonance circuit. Connect instruments minimum(LED does not glows or glows very dim).
as shown in Fig 2. This is the resonance frequency of the parallel resonance
The LED in the circuit is to get a visual indication of the circuit because at parallel resonance, current I through the
current through the circuit at different frequencies. parallel LC circuit will be minimum.
6 Compare and record the difference in the resonance
frequency calculated at step 3 and that measured in
step 5.
7 Vary the input frequency in steps of 500 Hz around the
resonance frequency as indicated in O&T sheet and in
each step record the value of circuit current.
8 From the recorded readings of current in step 6, plot a
graph of frequency versus current and mark the reso-
nance frequency of the LC parallel circuit.
9 Mark the -3dB points on the plotted graph. Find
bandwidth(BW) and quality factor Q.
3 Knowing the values of L and C, calculate and record the
10 Get the working of the circuit, recorded readings and the
resonance frequency of the parallel resonance circuit.
graph checked by your instructor.
4 Set the output of the signal generator to 4V and
rms
frequency to 1KHz. Record the current, I through the
circuit.
Ensure that the current through the circuit is around 10 to
12 mA and not more. If more current is flowing, reduce the
output level of the signal generator. LED will glow at all
frequencies other than at the resonant frequency.

IT & ITES : ICTSM - Exercise 1.2.20 79

TASK 4: Finding Inductance value of an unknown Inductor

3 Knowing the value of C and f , calculate and record the

Note: You may use the solenoid coil used by r
another trainee in task-1 as an unknown value inductance value of the unknown inductor using the
inductor. formula given below;
At resonance, X = X
1 Connect the unknown value inductor in place of the coil L C
connected in the LC parallel circuit at Fig 2. 1 1
or 2πfr L = 2π f C or L = 2 2
2 Set the output level of the of signal generator to around r 4π fr C
4V .Increase the output frequency gradually from 50 4 From the found value of L recalculate the resonance
rms
Hz and record the resonance frequency f at which the frequency f to reconfirm the found value of L.
r r
circuit current becomes minimum(LED does not glow
or glows very dim). 5 Get your work checked by your instructor.
This is the resonance frequency of the parallel resonance
circuit formed by the unknown value of C and unknown
value of L.

Lab Assignment : Connect a known value inductor in circuit at Fig 1 and an unknown value capacitor.
Repeat task 2 to find the unknown capacitor value.
Note: An unknown capacitor value can also be found using series resonance circuit.

80 IT & ITES : ICTSM - Exercise 1.2.20

 Record Sheet for Exercise 1.2.20

TASK 1:- Reasonance frequency and circuit current of series LC

1 Measured value of Inductance (L) used :

2 Value of capacitance (C) used :

3 Calculated series reasonance frequency f :

r
4 Measured values at resonance
(a) Reasonance frequency, f :
r
(b) Circuit curent, I :

5 Difference between calculated and measured f :

r
6 Circuit current at different frequencies
(Note: Knowing the valuesof f at item 4 above, enter frequency values in the Table given below):
r

Frequency f –2KHz f –1.5KHz f –1KHz f –500Hz f f +500Hz f +1KHz f +1.5KHz f +2KHz

r r r r r r r r r
= = = = = = = = =

7 Frequency versus current of series LC TASK 2: Finding unknown value of L.

1 2 3 4 5 6 7 8 91 2 3 4 5 6 7 8 91 2 3 4 5 6 7 8 91
1 Value of capacitor used :

2 Measured reasonance frequency f :

r
3 Calculated value of L using the :
1
formula, L = 2
4π fr 2 C

4 Calculated value of f from :

r
calculated value of L

8 Instructor’s remarks:
Very good Good Satisfactory Poor

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.2.20 81

TASK 3:- Reasonance frequency and circuit current of Parallel LC

1 Measured value of Inductance (L) used :

2 Value of capacitance (C) used :

3 Calculated Parallel reasonance frequency f :

r
4 Measured values at resonance
(a) Reasonance frequency, f :
r
(b) Circuit curent, I :

5 Difference between calculated and measured f :

r
6 Circuit current at different frequencies

Frequency f –2KHz f –1.5KHz f –1KHz f –500Hz f f +500Hz f +1KHz f +1.5KHz f +2KHz

r r r r r r r r r
= = = = = = = = =

7 Frequency versus current of parallel LC

1 2 3 4 5 6 7 8 91 2 3 4 5 6 7 8 91 2 3 4 5 6 7 8 91

8 Bandwidth (BW) :

9 Quality factor Q :

10 Instructor’s remarks :

(Trainee) (Instructor)

82 IT & ITES : ICTSM - Exercise 1.2.20

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.21

Identify and measure voltage of dry cells/battery

Objectives: At the end of this exercise you shall be able to
• identify types of cells from their size and printed data
• identify the +ve and -ve terminals of cells
• measure voltage of dry cells using single range voltmeter
• identify available ranges in the given multimeter
• set controls, choose suitable range for measurement
• measure voltages and currents.

Requirements

Tools/Equipments/Instruments D size - 2 Nos.

• DC voltmeter C size - 2 Nos.
0-5 volts ( per batch) - 1 No AA size - 2 Nos.
0-10 volts ( per batch) - 1 No AAA size - 2 Nos.
• Multimeter with Probes - 1 No (b) Rectangular battery (9 volts) - 2 Nos.
• Regulated DC power supply(0-24V) - 1 No. (c) Button cells
Mercury cell - 2 Nos.
Materials/Components Silver oxide cell - 2 Nos.
• Assorted dry batteries/cells of Lithium cell - 2 Nos.
different types, sizes, voltages as Nickel-cadmium cell - 2 Nos.
listed below. (d) Nickel-cadmium rechargeable
(a) Cylindrical cells battery AA size - 2 Nos.
(Rechargeable,non-chargeable, • Banana-to-crocodile patch cords - 2 Sets.
non-alkaline and alkaline)

PROCEDURE

TASK 1 : Identify type, size, terminals and measure battery/cell voltage

1 Take any one of the labeled dry cell. Enter its label 3 Get the recorded details checked by your instructor.
number in table-1 of record sheet.
4 Repeat steps 1 to 2 for the remaining cells.
2 From the information printed on the cell, identify the cell
5 Get your work checked by your instructor.
type, size/size code and its rated voltage. Record the
identified details in the corresponding columns of
table-1.

TASK 2 : Measure dry cell voltage using single range volt meter

1 Identify the specification of the meter from the dial scale 5 Take one of the cell from the given lot. Identify the +ve
markings on the meter and get it checked by your and -ve terminals of the cell. Clean its terminals using
instructor. cloth/paper.
2 Check if the single range meter given to you is the 6 Check if the meter chosen is suitable to measure the
correct choive for measuring DC dry cell/battery pack voltage of the chosen cell. If found not, consult your
voltage ranging from 1.5 volts to 9 volts. instructor.
3 Carryout mechanical zero setting of the single range 7 Hold the -ve test prod(black) of the meter at the -ve
meter as practiced in previous exercise and get it terminal of the cell as shown in Fig 1.
checked by your instructor.
8 Touch the +ve prod (red) of the meter to the +ve terminal
4 Connect te meter prods of the meter observing +ve and of the battery as shown in Fig 1, observing the pointer
-ve terminals of the voltmeter and the colour of the deflection.
prods. Get it checked by your instructor

83
If the pointer deflects below ‘0’ of meter, the identified cell
1
polarity or meter terminal is wrong polarity. Recheck the
polarities and interchange connections. Repeat steps 8
and 9.
9 Holding the meter prodes at the cell terminals, read and
record the voltage of the battery shown by the meter in
column-5 of table-1.
10 Repeat steps 5 to 9 for the remaining cells.
11 From the measured output voltage of the cells, con-
clude the usability of each cell and note down your
conclusion in column-6 of table-1.
12 Get your work checked by your instructor.

TASK 3 : Preparing to measure dc voltage using a Multimeter

1 In the given multimeter, check the available dc ranges, 4 Connect the meter prodes ensuring proper colour of
scales and other information. Record these details in prod at meter terminals.
Table 2 and 3 of record sheet.
5 Get your work done in Steps 1,to 4 checked by your
2 Check the symbol on meter dial and identify the instructor.
position in which it has to be palced while using it.
3 Carryout mechanical zero setting of the meter if found
necessary.

TASK 4 : Measuring dc voltage of dry cells using Multimeter

1 Record the type, size/size code and the rated 8 Set the meter range to measure the unknown DC
voltage of the given pentorch (AA size) cells in O&T voltage from the regulated DC power supply unit (RPSU)
sheet. set by your instructor.
2 Set the multi meter dc voltage range switch to measure
rated cell voltage. Identify the scale to be observed for The set voltage is DC and can be any value
taking readings. between 1volt to 24 volts.

3 Measure and record the voltage of the cell. 9 Measure the output voltage of RPSU. Reduce the set
4 Repeat steps above to measure and record the voltage measuring range of the meter if found necessary to
of the given dry cells and cell packs/battery. measure the voltage more accurately. Record the
measured voltage in O&T sheet. Get it checked by our
5 Place the two given AA cells a cell holder instructor.
In the cell holder, the cells will be in series. Readings taken on meter will be more accu-
Therefore across the terminals of the cell holder, rate, when the range selected is such that the
the voltage will be sum of the voltages of each pointer is pointing around the middle of the
cell. scale.
6 Set the multimeter in dc voltage range suitable to 10 Ask your instructor to change the set output voltage of
measure the cell pack voltage. Get it checkes by your RPSU and repeat steps 8 and 9.
instructor.
11 Get your work checked by your instructor.
7 Measure and record the voltage of the cell pack and get
it checked by your instructor.

84 IT & ITES : ICTSM - Exercise 1.2.21

TASK 5: Measure DC current using multimeter

The procedure given below should be carried 3 Measure and record the readings shown by the meter.
out only after your instructor connects a Change the set range if necessary to measure value of
component known as Resistor at the one of the current more accurately.
terminal of the RPSU. Details about this resistor Readings taken on meter will be more accurate, when
which is used to limit current is discussed in the range selected is such that the pointer is pointing
further lessons around the middle of the scale.
Never connect a current meter directly across 4 Ask your instructor to change the value of resistor such
the output terminal of RPSU. This will damage that a different value of current flows. Repeat steps 1,2
the meter permanently as well as the RPSU. and 3.
5 Repeat steps above to measure at least ten different
1 Set the multi meter dc current range switch to measure values of dc current.
unknown value of DC current .
6 Get your work checked by your instructor.
2 Connect the meter terminals as shown in Fig 2.

IT & ITES : ICTSM - Exercise 1.2.21 85

 Record sheet for Exercise 1.2.21
1 Table 1
Cell Type of Size Rated Measured Usability
Label cell Code Output Output voltage Fit / Unfit
No. voltage of cell

(1) (2) (3) (4) (5) (6)

SAMPLE Zinc D 1.5 V 1.1 V Unfit

Carbon

10

2 Name of the given multimeter & model number :

3 Manufacturers name :
4 Position in which the meter should be kept during measurement :
5 List the input sockets available on the meter.
i
ii
iii

6 List the available measuring ranges and scale marking on the meter:

Table 2: DC voltage ranges 8 Give the maximum and minimum DC current

No. of Range Suitable meter Value of that can be measured using the given meter:
ranges setting scale marking one SSD
Max. Min.
Sample 1V 0-100 0.2 Volts
9 Measured voltage of AA cells :
Cell 1 : _______ V Cell 2 : _______ V
10 Measured voltage of cell pack : _______ V

11 Measured voltages of RPSU output:

First setting : _______ V
Second setting : _______ V
7 Give the maximum and minimum DC voltage
that can be measured using the given meter. 12 Measured currents:
Max. Min. First setting : _______ V
Second setting : _______ V

86 IT & ITES : ICTSM - Exercise 1.2.21

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.22

Form a DC source 6V/500 mA using 1.5V cells

Objectives: At the end of this exercise you shall be able to
• identify the polarity of a cell (R)
• measure the voltage of each cell
• connect cells in series
• connect cells/battery in parallel
• measure internal resistance of a primary cell.

Requirements

Tools/Equipments/Instruments Materials/Components
• Ammeter 0 to 1A - 1 No. • Cells 1.5 V - 8 Nos.
• Ammeter 0 to 500mA - 2 Nos. • SP switch 6A 250 V - 4 Nos.
• Voltmeter 0 to 15V - 1 No. • Connecting leads, assorted -10 Nos.
• Multimeter - 1 No. • Resistor 10 ohms 5W -1 No.
• Rheostat 200 ohms 3.7A - 1 No. • Resistor 5 ohms 10W -1 No.
• 4-cell battery pack -2 Nos.
• Miniature lamp 6V/9V 300 mA -1 No.
• Resistor 3 ohms 5W -1 No.

PROCEDURE

TASK 1: Determine the internal resistance of primary cells

1 Observe the polarity marking of the cell on the body. To 4 If the deflection is reversed as shown in Fig 1(b),
ensure correctness of marking, go to step 2. interchange the prods touching the cell and observe for
2 Establish connection of the given cell to a moving coil the correct deflection. Mark/note the cell's polarity.
voltmeter as shown in Fig 1. 5 Form the circuit as shown in Fig 2.
3 Observe the meter deflection. Correct deflection indi-
cates that the polarity of the cell is the same as that of
meter polarity.

6 Keep the switch open and measure the voltage across

the cell terminal. Record the reading in Table 1.
7 Close the switch S. Measure the terminal voltage and
load current.
8 Record the readings in Table 1.
9 Determine the internal resistance using the formula
E - V
Ri = IL ohms and record it in Table 1.

10 Repeat the steps 5 to 9 for different makes and sizes

(Type No.) of primary cells.

87
 TABLE 1

E - V
Type cell Voltage 'E' without Voltage 'V' Voltage drop in Load current Ri = Ω
IL mΩ
load with load cell = E – V in mA IL

Conclusion If a load is connected to a cell, the terminal voltage of

The open circuit voltage of the cell is called . the cell .
The change in terminal voltage is due to .

TASK 2: Series connection

1 Check the individual cells for their condition.

– Select 500mA DC current range in multimeter or 500mA
DC ammeter.
– Connect the cell across the meter in series with a 3 ohm
resistor.
– Watch the deflection. Full deflection shows good con-
dition of the cell. Low deflection shows discharged
condition of the cell.

Cells having a higher internal resistance should

not be used for series connection.
Care should be taken for the cell's polarity.

2 Connect the cells as shown in Fig 3. 5 Record your observations under the columns 3 & 4 in
3 Measure the voltage of one cell V1, two cells V2, three Table 2.
cells V3 and four cells V4 connected in series. Record Conclusion
your observations in the first and second columns of
Table 2. The effect of connecting cells in series is to
the terminal voltage that
4 Contact the terminal `G' to the terminal A and observe the is equal to
ammeter reading and the glow condition of the lamp.
Change the contact of terminal `G' to terminals B, C and To obtain a higher voltage, cells should be
'D' in succession.

TABLE 2

Sl.No. No. of cells in series Voltmeter reading I Glow

1
2
3
4

88 IT & ITES : ICTSM - Exercise 1.2.22

TASK 3: Parallel connection

1 Check the voltage of each cell. TABLE 3

2 Form the circuit as shown in Fig 4.
S.No. No.of cells in parallel V I
3 Close the switch S1 and measure voltage and current.
Record the values in Table 3, under columns 1, 2 and
3.
4 Observe and record the readings of V and I after closing
switch S2, then S3, and S4 in succession.

Unequal voltage cells cannot be connected in

parallel.

Conclusion
When cells of equal voltage are connected in parallel the
terminal voltage is equal to

As the load current is shared by the cells in parallel, the

terminal voltage across the load is
when compared to a
single cell supplying current to the same load.
The effect of a number of cells in parallel to a given load.

TASK 4: Grouping of cells

Series parallel combination for higher voltage and higher

current

1 Set the movable arm of 20 ohms 3.7A rheostat to get

12 ohms with the help of an ohmmeter.
2 Connect four 1.5 V cells in series to form one group.
Form one more similar group of 4 cells. (Fig 5)
3 Connect two series groups of 4 cells and form the
circuit as shown in Fig 5.

4 Close switch S1, observe the voltmeter and ammeter.

Record the values in row 1 of Table 4.
5 Keep the switch positions S1, S2 and S3 as indicated
in row 2 of Table 4. Record V and I in the respective
columns.
6 Repeat step 5 for different combinations of switch
positions as indicated in rows 3 to 6 of Table 4.
Both the open circuit voltages of group (a) and group (b) Conclusion
should be the same, or more correctly their TPD should
be the same when supplying the same load current. When group `A' alone supplies the load current, the fall
in voltage (EMF - TPD) is

IT & ITES : ICTSM - Exercise 1.2.22 89

 When group `B' alone supplies the load current, the fall The no-load voltage in series-parallel combination
in voltage (EMF - TPD) is

The total current drawn by the load is equal to the sum

This indicates that the internal resistance of group `A' of the
is the internal resistance of
group `B'.

TABLE 4
Row Position of the switches I1 I2 V
S1 S2 S3
1 Close Open Open
2 Close Open Close
3 Open Close Open
4 Open Close Close
5 Close Close Open
6 Close Close Close

90 IT & ITES : ICTSM - Exercise 1.2.22

IT & ITES
ICTSM - Basic Electrical Exercise 1.2.23

Routine maintenance of Lead-acid battery

Objectives: At the end of this exercise you shall be able to
• identify the rated output voltage and Ah capacity of given battery
• clean the terminals and supports
• check and top up the electrolyte level
• measure the specific gravity of the electrolyte and voltage of the cells
• conclude if the battery is ready for use or needs recharging.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Sandpaper - as reqd.
• Battery hydrometer - 1 No./batch. • Cleaning cloth - as reqd.
• Lead-acid storage battery, 6V or • Baking soda - as reqd.
12V 80Ah - 1 No./batch. • Petroleum jelly - as reqd.
• 12 volts, Battery charger - 1 No./batch. • Distilled water - as reqd.
• Cleaning brush, 2 inch - 1 No./batch.

PROCEDURE

TASK 1: Check the initial condition of a lead-acid battery

1 From the name plate or from the code number on the 3 Check for the presence of vent plugs. If any of the vent
cell identify and record the following in record sheet; plug is broken or absent record in record sheet.
– Manufacturer 4 Unscrew/open all the vent plugs of the battery. Check
and record if the level of electrolyte is normal or low.
– Output voltage
5 Using battery hydrometer, check and record the spe-
– Number of cells
cific gravity of electrolyte in each cell. Put back the vent
– Type number plugs.
– Ah capacity 6 Measure and record the voltage across each cell and
2 Check the battery terminals and metal links for the the total voltage across battery terminals.
following defects if any, and record defects if found; 7 From the readings recorded in steps 4,5 and 6 record
– Broken or lifted terminals your conclusion about the condition of cells and the
battery.
– White or grey colour sulphation on and near the
terminals If cell voltage is less than 1.6, that cell is called
– Salt formation on the battery top Dead cell.

– Cell links cracked 8 Get the recorded readings checked by your instructor.
– Cracked or warping of battery top

TASK 2: General Lead-acid battery maintenance

1 Close the vent holes fully. Clean the battery terminals 2 Clean the battery top using moist cloth, baking soda
and metallic links using sand paper. Brush the dirt from and water. Dry the battery top using a dry cloth.
battery top.
3 Open the vent plugs of the battery. If the level of
If vent holes are not closed while cleaning dust/ electrolyte is low, top-up using distilled water till the
dirt may fall inside the battery and damage/ level of electrolyte is 10-15mm above the plates. Get it
reduce life of the battery. checked by your instructor.

91
4 After topping-up all cells measure and record the 7 Compare the calculated voltage of each cell (at step-
specific gravity of the electrolyte of each cell. 5) and the measured voltage of cells (at step-6). Check
if both values are almost same. If the values are found
5 From the measured values of the specific gravity of each
very different, consult your instructor.
cell, calculate and record the approximate output volt-
age of each cell using the formula, 8 Measure and record the total battery voltage.
Vout = Specific gravity + 0.84. 9 From the cell voltages and battery voltage recorded,
record your conclusion on the condition of the battery
6 Measure and record the voltage of each cell.
in the record sheet.
If any cell voltage is still found less than 1.6 V, 10 Get your work checked by your instructor.
the cells can be considered as dead.

TASK 3: Charging a 12Volt battery using a battery charger

1 Check if the battery to be charged is live and not dead. 7 Switch-off the battery charger and disconnected the
If the total voltage of the battery is less than 9.6 volts, wires connected between the battery charger and the
then the battery can be considered as dead and is not battery.
advised to charge the battery. In such a case consult 8 Measure and record the specific gravity of the electro-
your instructor before carrying out further steps. lyte & voltage of cells. Record the total voltage of the
2 Record the voltage of each cell and the total battery battery.
voltage in record sheet. 9 Get the charged battery and the recorded readings
3 Record the specific gravity of electrolyte in each cell. checked by your instructor.

4 Using the lengthy wires of the battery charger, connect 10 As demonstrated by your instructor, check the charged
the positive and Negative wires of the charger to the battery for its working voltage under load using a high
corresponding positive and negative end terminals of rate discharge tester.
the battery. Get the connections checked by the
instructor. Do Not keep the high rate discharge tester
across the battery terminal for more than 4 to 5
5 Switch-on the battery charger and record the initial seconds. Otherwise the battery will get dis-
charging current in record sheet. charged unnecessarily.
6 Allow the battery to charge and record battery voltage
and charging current at intervals of every 30 minutes. 11 Get your work checked by your instructor.
Charge the battery for a period of 60 minutes or till the
battery is fully charged whichever is earlier.

Sometimes it may take a few hours to charge a

battery. This depends both on the condition of
the battery and on the type of charger used.
Since, the practical is for a period of 5 hours
only, the charging of battery is restricted to 60
minutes. The trainees may put the battery on
charging during the next practical class if found
necessary. Consult your instructor for further
details.

92 IT & ITES : ICTSM - Exercise 1.2.23

 Record sheet for Exercise 1.2.23

TASK 1: (Initial condition - Before topping-up)

1 Battery specification :

Manufacturer Type Nominal Ah Number

Name number output voltage capacity of cells

2 Physical defects found (if any):

Normal Low Very low

3 Level of electrolyte in cells :
(Compared with top of plates) (10-15mm above) (10-15mm below) (below 15mm)

Cell-1 Cell-2 Cell-3 Cell-4 Cell-5 Cell-6

4 Measured specific gravity of cells :
(record specific gravity in box)
Total
5 Measured voltage of cells :
(record voltage level in box)
Can be serviced Dead battery
6 Trainees conclusion on the servicability of battery :

Proceed to task-2 Repeat task-1

7 Instructors remarks :

TASK 2 : (After cleaning and topping-up cells)

Good Satisfactory Poor Continue

1 Instructors remarks after topping-up:

Cell-1 Cell-2 Cell-3 Cell-4 Cell-5 Cell-6

2 Measured specific gravity of cells :

3 Calculated values of cell voltages :

Total
4 Measured voltage of cells :

5 Trainees conclusion on the condition of the battery :

Ready for use To be charged Dead battery

6 Instructors remarks on the overall work done by the trainee:

IT & ITES : ICTSM - Exercise 1.2.23 93

94
Record sheet for Exercise 1.2.23

TASK 3: (Battery charging condition)

Cell Initial condition Charged condition after

No. Specific voltage 30min 1 Hrs 1.30 Hrs 2 Hrs 2.30 Hrs 3 Hrs 3.30 Hrs 4 Hrs 4.30 Hrs 5 Hrs
gravity Sp. V Sp. V Sp. V Sp. V Sp. V Sp. V Sp. V Sp. V Sp. V Sp. V

IT & ITES : ICTSM - Exercise 1.2.23

5

(Trainee) (Instructor)
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.01

Identification of Rectifier diodes, its specifications and testing

Objectives: At the end of this exercise you shall be able to
• identify the type of package and terminals of the diode
• determine the forward to reverse resistance ratio of diodes
• identify good/bad diodes
• use a diode as a switch
• find and plot the forward characteristics of a diode.

Requirements

Tools/Equipments/Instruments • Patch cords - as reqd.

• Tag board - 1 No.
• Trainees kit.
• Semiconductor diodes,
• Regulated PSU, 0-30V, 1A - 1 No./batch.
1N4007 or BY127 or equivalent - 1 No.
• DC milliammeter, 0-500 mA - 1 No./batch.
• Lamp, 6V, 300 mA - 1 No.
• DC micro-ammeter, 0-10 μA - 1 No./batch.
• Suitable type Lamp-holder - 1 No.
• DC milli-voltmeter, 0-1000 mV - 1 No./batch.
• Resistor, 470Ω, 1/2 W - 1 No.
Materials/Components • Hook-up wires, Red, Black - 0.2m each.
• Assorted types of diodes - 30 Nos.
• Red colour sleeve wire - 10 cms.

PROCEDURE

TASK 1: Identify diode package, diode terminals and find its specifications

1 Pick any one of the labelled diodes from the given 4 Referring diode data manual, identify and record the
assorted lot. Record its label number and the type specifications of the chosen diode in table 2 of record
number (E.g., BY 127, 1N 40001, etc.,) printed on the sheet.
diode in Table 1 of the record sheet.
As a help, sample specifications for a popular diode is
2 Referring chart-1 of lesson 1.3.01, identify and record given in Table 1. Record atleast two equivalents for each
the type of package of the chosen diode. (such as diode under check.
glass/plastic/ceramic/metal etc.).
5 Get the identifed specifications checked by your in-
3 From the physical appearance of the diode or markings structor.
on the diode, identify and put a small red colour sleeve
over the anode terminal of the diode. 6 Repeat step 1 to 4 for atleast 10 different types of
diodes.
Refer chart 1 of lesson 1.3.01 for physical appearance
of a few popular types of diodes. 7 Get your work checked by your instructor.

TASK 2: Check the electrical condition of diodes using ohmmeter/multimeter.

1 Pick any one diode used in task 1. Record its label 4 Reverse the meter probes connected to the diode as
number, type number, package type in table 2 of record shown in Fig 1b. Record the reading shown by the meter
sheet. in the Table 2.
2 Set the ohmmeter/multimeter to x100 ohms range. 5 From the readings noted in steps 3 and 4, calculate and
Carryout resistance-zero-setting of meter. record the ratio of forward to reverse resistance of the
Choose other ohms range if necessary, but carryout diode.
resistance zero setting of meter for the chosen range. 6 From the recorded information give your conclusion
3 Connect the ohmmeter across the diode terminals as about the condition of the diode.
shown in Fig 1a. Record the resistance reading shown
by the meter in Table 2 of record sheet.
95
 Use the tips given below for making conclusion;
– In good diodes, resistance will be less than 100
ohms in one direction and very high or almost
infinity/open in the other direction. In the worst
cases the ratio between low to high resistance could
be at least 1:1000.
– Shorted diodes show zero or Very low resistance in
both directions.
– Open diodes shows infinity/open in both directions.
7 Get the recorded readings and conclusion checked by
your instructor.
8 Repeat step 3 to 6 for atleast ten more diodes of different
types code number.
9 Get your work checked by your instructor.

TASK 3: To test Diode function as a switch

1 Pick one of the good diode used in previous tasks.

Check to confirm the good physical and electrical
condition of the given lamp and lamp-holder.
2 Record the type number of the chosen diode in Table 3
of record sheet.
3 Identify the anode and cathode terminals of the diode.
Put a red wire sleeve to the anode terminal of the diode.
Measure and record the DC forward and reverse resist-
ance of the diode in Table 3.
4 Measure and record the resistance of the lamp in table-
3.
5 Refer Fig 2a and 2b and solder the components on the
tag/lug board.
6 Get the correctness and neatness of the wiring checked
by your instructor.
7 Switch ON DC power supply unit (DC PSU) and set
output to 6V. Check, if the lamp in the wired circuit
glows. Record your observation in Table 4.
If the lamp is not glowing, consult your instructor.
8 Measure and record the voltage across lamp VL, forward
voltage drop across diode Vd and current Id in Table 4.
9 From the recorded readings and the observed lamp
status (GLOW/OFF), record your conclusion about the
behaviour of the diode as a switch (ON/OFF).
10 Switch-off DC PSU. Reverse the diode connection in
the circuit as shown in Fig 3,. Replace the milliammeter
by a 0-10 micro-ammeter. Remove the 0-1000 mV
meter connected across the diode and connect
multimeter in 10V range across the diode.

96 IT & ITES : ICTSM - Exercise 1.3.01

 11 Repeat steps 7, 8 and 9.
Note: If you DON'T disconnect the 0-1000mV
meter, the meter will get damaged as the 12 Switch-off power to the circuit. Get your readings
voltage appearing across the diode in reverse checked by your Instructor.
bias condition will be equal to supply voltage.

TASK 4: To find Forward bias characteristics of a diode

1 Modify the diode test circuit by adding a resistor in

series with the diode as shown in Fig 4.
2 Get the wiring checked by your instructor.
3 Set output of DC PSU to 0 volts. Switch-on DC PSU and
increase the output voltage of the PSU such that the
diode drop Vf varies as given in Table 5 of record sheet.
At each step record the values of If.
4 Switch-off PSU. For each recorded set of values of Vf
and If, calculate and record the forward resistance Rf
of the diode.
5 From the recorded readings in Table 5, plot a graph of
Vf and If in record sheet. 6 Get your work checked by your instructor.

Space for recording additional tips given by the instructor

IT & ITES : ICTSM - Exercise 1.3.01 97

98
Record shet for Exercise 1.3.01

1 Table - 1: Diode Specifications and equivalents

Label Type number Material Rated peak Maximum reverse Maximuim average Forward voltage Function/ Equivalent
No. printed Si/Ge/Se/Others reverse voltage current @ VR forward current drop @ IF applica- diode
on diode VR IVr IF VF tion type(s)

IT & ITES : ICTSM - Exercise 1.3.01

TASK 2
Table 2

Resistance value in Ratio between Condition

Code Number
Label printed on Type of forward and reverse of diode
Number package one opposite resistance FIT/UNFIT
the DIODE
direction direction

IT & ITES : ICTSM - Exercise 1.3.01 99

TASK 3 and 4
Table 3

Diode Type number : ____________Ω Instructors remarks on the neatness and correct-
DC forward resistance of diode : ____________Ω ness of the wired test set-up.
DC reverse resistance of diode : ____________Ω Very good Good Satisfactory Poor/Redo

Lamp resistance : ____________Ω

4 Table 4

Type of diode Status of lamp Drop across Diode current Drop across Behaviour of diode
biasing (Glows/OFF) diode, V volts I mA lamp, V volts as a switch (OFF/ON)
d d L
Forward

Reverse

5 Table 5 : Forward bias characteristics GRAPH: Forward characteristics

Forward drop Forward Forward diode

across diode current resistance
V
V in mV I mA R = fΩ
f f f I
f

100 mV
200 mV
300 mV
400 mV
500 mV
600 mV
700 mV
800 mV
900 mV
1 Volt

6 Complete the following sentences:

(From forward characteristics)
1 From the recorded readings in Table 2, the turn on voltage of the diode is _____________ volts.
2 From the turn on voltage level of the diode, the diode is made of _____________ semiconductor material.
3 Between V = 400 mV to V = 700 mV the change in current is _____________ mA.
f f
4 The forward resistance of a diode after V = 500 mV is _____________ ohms.
f
5 The forward resistance of a diode after V = 700 mV is _____________ ohms.
f

(Trainee) (Instructor)

100 IT & ITES : ICTSM - Exercise 1.3.01

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.02

Construct and test Half-wave and Full-wave rectifiers using diodes

Objectives: At the end of this exercise you shall be able to
• construct a half-wave rectifier
• determine the output DC voltage
• measure voltage levels
• measure waveform parameters using CRO.
• construct and test a full wave rectifier using two diodes.

Requirements

Tools/Equipments/Instruments • Step-down transformer,

240V: 12-0-12V, 24VA - 1 No.
• Trainees kit - 1 No.
• Multi-strand wire, Red, Blue - as reqd.
• CRO, 20 MHz, dual trace - 1 No./batch.
• Mains cord with 2-pin plug - 1 No.
Materials/Components • Nuts, bolts and washers - as reqd.
• Tag board (soldered with diode • Hook-up wires (red and black) - as reqd.
and resistor at Ex.1.3.01) - 1 No. • Semiconductor diode, 1N 4007 - 1 No.
• BASE BOARD (Wooden) - 1 No.

PROCEDURE

TASK 1: Construct and test a half-wave rectifier

1 Test the continuity of the primary and secondary 2 Record the specifications of the tested transformer in
windings of the given transformer to confirm its satisfac- the record sheet.
tory condition.
3 Using the wired board of Exercise 1.3.01, construct a
Exchange, if the given transformer was found defective. half-wave rectifier by carrying out the necessary modi-
fication, referring to Fig 1. Follow the order of steps given
below;

101
 – Mount the tested transformer as shown in Fig 1 on 9 Set the Volt/div and Time/div of CH-1 and CH-2 such
the Tag board using suitable size nuts, washers that the two waveforms are seen clearly on the CRO.
and bolts. Get it checked by your instructor.
– Mount the wired half wave rectifier tag board using
nuts, washers and bolts.
– Solder the wire connection and the two-core power
cord as shown in Fig 1.
– Using twine, tie the power cord to the base board as
shown in Fig 1.
4 Connect the mains power cord of the wired circuit and
switch-on AC mains. Measure and record the mains
voltage across transformer primary and stepped-down
AC voltage, VS(rms) across the transformer secondary.
5 Calculate and record the expected DC voltage across
load RL using the formula,
Vdc = 0.45 VS(rms) ,
10 From the displayed waveforms on the screen,
where, VS(rms) is the AC input to rectifier.
measure and record the following parameters;
6 Measure and record the rectified DC voltage Vdc across
– Peak value of VS
load RL ( 470 ohms).
– Frequency of VS
7 Record in table the difference in calculated and meas-
ured values of rectified voltage. Get it checked by your – Peak value of pulsating Vdc
instructor.
– Frequency of pulsating Vdc
8 Connect the two channel input probes of CRO as
11 Show the wave-forms and the recorded readings to your
shown in Fig 2.
instructor.
By this you can simultaneously view input(AC) and
12 Switch-off AC mains. Disconnect mains cable and
output(DC) of the diode.
switch-off CRO.

TASK 2: Construct and test a Full wave rectifier

1 Modify the wired half-wave rectifier board at Task 1 to 4 Measure and record the rectified output Vdc across RL.
construct a full wave rectifier as shown in Fig 3. Check
5 Find and record the difference in the calculated and
the components before soldering in the circuit.
measured values of output DC voltage.
2 Power-on the circuit. Measure and record the AC input
6 Using CRO measure and record the following;
VS(rms) to the rectifier across the center-tap and any one
end of the transformer. – Peak value of VS
3 Calculate and record the expected DC voltage across – Frequency of VS
load RL using the formula given below;
– Peak value of pulsating Vdc
In a full wave rectifier, Vdc = 0.9 x VS(rms),
– Frequency of pulsating Vdc
where, VS(rms) is the voltage across the center-tap and 7 Get the waveforms and recorded readings checked by
any one end terminal of the secondary. yout instructor. Switch of Mains supply and CRO.

102 IT & ITES : ICTSM - Exercise 1.3.02

 Record Sheet for Exercise 1.3.02

Task 1

I. Transformer Specifications

Type of transformer : Type of Core :

Rated primary voltage : Rated secondary voltage :

Rated secondary current : VA rating :

II. Experimental details

(1) Mains supply voltage : V (6) Peak value of input : Volts

rms
Vs(
peak)
(2) Secondary voltage Vs( : V (7) Frequency of input signal : Hertz
rms) rms
(input to HW Rectifier)

(3) Expected DC output V : Volts (8) Peak value of pulsating : Volts

dc
DC output

(4) Measured DC output V : Volts (9) Frequency of pulsating : Hertz

dc
DC output

(5) Difference of (3) and (4) : Volts

IT & ITES : ICTSM - Exercise 1.3.02 103

Task 2
Transformer specification
(1) Rated primary voltage : (2) Rated secondary voltage :

(3) Rated secondary current or VA rating transformer :

II Readings of two-diode full-wave rectifier

V Calculated Measured Difference Peak value Frequency Peak value Frequency
s(rms)
V volts V volts of 2 & 3 of V of V of pulsating V of pulsating V
dc dc s s dc dc
1 2 3 4 5 6 7 8

(Trainee) (Instructor)

104 IT & ITES : ICTSM - Exercise 1.3.02

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.03

Construct and test a Bridge rectifier

Objectives: At the end of this exercise you shall be able to
• construct the bridge rectifier
• determine the output DC voltage
• measure voltage levels
• measure the waveform parameters using CRO.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit - 1 No. • Tag board mounted with transformer and
• CRO, 20 MHz, dual trace - 1 No./batch. wiredfullwave rectifier(2 diode) at Ex.1.3.02)- 1 No.
• Hook-up wires (red and black) - as reqd.
• Semiconductor diode,1N 4007 or Equv., - 2 Nos.
• Resistor 220 ohms, 5 Watts - 1 No.

PROCEDURE

TASK 1: Construct and test a Bridge rectifier

1 Measure the primary and secondary output voltages/ Test the two new diodes to be used before assembling.
currents of transformer. Record values in record sheet.
3 Get the wired circuit checked by your instructor.
2 Modify the two diode full wave rectifier wired in exercise
4 Power-on the wired circuit. Measure and record the AC
1.3.02 to construct a bridge rectifier as shown in Fig 1.
input VS(rms) to the rectifier in record sheet.

105
5 Calculate and record the expected output DC voltage 8 Using a CRO measure and record the peak ac input
Vdc across load RL using the formula, voltage to the rectifier, peak value of pulsuating DC
voltage and ripple frequency.
In a bridge rectifier, Vdc= 0.9 VS(rms)
9 Show the waveforms and recorded readings to your
where, V S(rms) is the AC input to rectifier(refer Fig1).
instructor.
6 Measure and record the output DC voltage Vdc across
10 Change the value of the load resistor RL from 470 ohms
the load RL in record sheet.
to 220 ohms and repeat steps 6,8 and 9.
7 Record the difference in the calculated and measured
11 Switch-off mains supply and CRO.
values. Get it checked by your instructor.

Record sheet for Exercise 1.3.03

I Transformer specifications

(1) Rated primary voltage : (2) Rated secondary voltage :

(3) Rated secondary current or VA rating transformer :

II Readings of Bridge rectifier with Load resistance of 470 Ohms.

Table 1
V Calculated Measured Difference Peak value Frequency Peak value Frequency
s(rms)
V volts V volts of 2 & 3 of V of V of pulsating V of pulsating V
dc dc s s dc dc
1 2 3 4 5 6 7 8

III Readings of Bridge rectifier with Load resistance of 220 Ohms.

Table 2
V Calculated Measured Difference Peak value Frequency Peak value Frequency
s(rms)
V volts V volts of 2 & 3 of V of V of pulsating V of pulsating V
dc dc s s dc dc
1 2 3 4 5 6 7 8

(Trainee) (Instructor)

106 IT & ITES : ICTSM - Exercise 1.3.03

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.04

Construct & test a rectifier circuit with capacitor filter

Objectives: At the end of this exercise you shall be able to
• determine value of C for a given load current
• wire and test a full wave rectifier with capacitor-input filter
• measure the ripple factor at different loads.
• identify the type, size and colour of LEDs
• identify the anode and cathode terminals of LEDs
• carry out a quick test using a meter to find its condition
• measure current and voltage drop for reasonable brightness
• calculate the required limiting resistor for a given LED as output indicator in a power supply.

Requirements

Tools/Equipments/Instruments • Electrolytic capacitor (see note) - as reqd.

• Assorted types, sizes and - 5 Nos.
• Trainees kit - 1 No.
colours of LEDs
• CRO, 20 MHz, dual trace - 1 No./batch.
• Red colour LED - 1 No.
Materials/Components (FLV117 or EQUV)
• Tag board with wired bridge • 220 Ω, 1/4 W resistor - 1 No.
rectifier at Ex.1.3.03 - 1 No. • 1KΩ, 1/4W carbon resistor - 1 No.
• Hook up wire (red, black) - as reqd. • 1KΩ potentiometer - 1 No.
• Resistors, 470Ω, 5W and • Patch cords - as reqd.
220Ω, 5W - 1 each. • Soldering paste - as reqd.
• Solder - as reqd.

Note:
In task-1, the value of capacitor should be calculated at step 1 and then to be collected for use.
In task-4 the value of resistor should be calculated at step 1 and then to be collected for use.

PROCEDURE

TASK 1:

1 To the constructed bridge rectifier in Ex. 1.3.03,

assuming a load current, IL of 80mA, calculate the
value of filter capacitor to be connected. Assume 10%
rule for ripple. Record the calculated value in record
sheet.
2 Choose a standard value capacitor whose value is
close to the calculated value of C in step 1. Get it
checked and approved by your instructor. Record the
chosen standard value capacitor.
3 Collect the chosen value of capacitor and solder it on
the tag board as shown in Fig 1.
4 Connect a DC 0-500mA in series with the load resistor
as shown in Fig 1. where, f is the supply frequency in Hz, 50Hz
5 From the values of RLand C used, calculate and record C is capacitance in μ Farads
the theoretical value of ripple factor r, using the formula, RLis resistance in ohms
1 2887 To find % ripple factor (% r), multiply calculated r by
r= or r=
4 3 fR C RC 100.
L L

Note that this formula is applicable for fullwave

rectifier.
107
6 Power-on the wired circuit. Measure and record values 8 From the measured values at step-7, calculate and record
of Vdc and IL in record sheet. From the measured value the values of Vdc and % ripple factor r using the formula;
of IL, recalculate and record the peak-to-peak ripple V
r(p – p)
Vr(p-p) using the formula, Vdc = Vout(peak) –
2
I
L
Vr(p – p)
≤ Vr(rms) V
fC %r = x100 where, Vr(rms) =
r(p – p)
r
V dc 2 3

9 Compare and record the difference in Vdcmeasured

using meter (at step-6) with the calculated value of Vdc
using Vout(peak) and Vr(p-p) (at step 8).

10 Get your readings checked by your instructor.

11 Change the value of load resistor RLfrom 470Ω to

220Ω, 5W and repeat steps 1 to 10.
7 Using CRO, referring Fig 2, measure and record the When 220Ω is connected as load, the load current will
following parameters in Table 1; be approximately, 34V/220Ω = 154mA. Hence, at step
– Peak value of pulsating Dc, Vout(peak) 1, take 160mA as load current to calculate the value of
– Peak-to-peak value of ripple Vr(peak-peak) C.

TASK 2: Identification and quick test of LEDs using ohmmeter

1 Label the given five LEDs(as 1,2,..). Take one of the

LEDs and enter its label number in Table 2 of the record
sheet.
2 Identify and record the type, size and colour of the LED.
Refer Lesson 1.3.04 for identifying the type and size of
LEDs.
3 Identify the anode and cathode leads of the LED
following the hints given in Fig 3a. Put a red sleeve wire
on the anode lead of LED as shown in Fig 3b.

A good single colour LED glows when the

meter prods are connected in one direction as
shown in Fig 4a. It does not glow when the
prods are reversed as in 4b.
4 Set multimeter in x1Ω range. Connect the meter prods A good double colour LED glows in one colour
across the LED terminals and check the condition of when the meter prods are connected in one
the LED following the hints given below. Record your direction and glows in a different colour when
observation in Table 2. the prods are reversed.
Observe the glow closely as the glow of LED may be A defective LED does not glow when the meter
dim due to weak batteries of the meter. prods are connected in either direction.

5 Repeat steps 1 to 4 for the given remaining LEDs.

6 Get your work checked by your instructor.

108 IT & ITES : ICTSM - Exercise 1.3.04

TASK 3: Measurement of If and Vf for reasonable brightness

1 Make a simple test set-up on the lug board as shown 2 Take any one of the good LED given to you in task-2.
in Fig 5. Keep in maximum resistance position. Clip it across terminals X and Y of the test set-up
Ensure that the DC supply voltage is set at 6 volts, shown in Fig 5.
as, current/voltage limiting resistor(R) value is cal- Ensure that +ve of DC supply is connected to the anode
culated assuming 6V supply. Also, if LED is con- of the LED; otherwise the LED may become defective.
nected in reverse by mistake since all LEDs gener-
ally withstand a reverse voltage < 6V, the LED will 3 Switch-on DC PSU. Adjust 1k pot such that the LED’s
not get damaged. glow is reasonably bright and visible. Record the
current If through the LED in Table 2.
4 Measure and record the voltage drop Vf across the LED.
5 Take the pot back to maximum resistance
position(minimum circuit current). Switch-off DC PSU
and take out the LED.
6 Repeat steps 2 to 5 for all the given five LEDs.
7 Get your readings checked by your instructor.

After completing this task, return the packet of

LEDs to your instructor.

TASK 4: Calculating value of limiting resistor and use of LED as output indicator

Hints to Instructor: Instructor to issue each trainee one red colour LED for this task. Note that this LED
will be used with the wired bridge rectifier power supply and hence will not be returned after this
exercise.

1 Carry out quick test on the given red LED to confirm its 5 If the calculated value of RS is not a standard resistor
satisfactory working condition. value, choose a value close to RS and recalculate LED
current. Get the calculated value of RS and standard
2 Find the current required for the LED to glow reason-
value of RS chosen checked by your instructor.
able brightness, and the voltage drop across it using
the test set-up wired at Task 3. Record values in Table 6 Collect the resistor and solder the resistor RS and LED
3. at the output of the bridge rectifier at tag points shown
in Fig 7.
3 Power-on the bridge rectifier with capacitor input filter
wired on tag board in task-1. Measure and record the Ensure that +ve of bridge rectifier output is connected
DC voltage across its output terminals. Switch-off to the anode of the LED.
power to the bridge rectifier.
7 Solder a 1KΩ, 1/4 watt resistor across the output
4 From the recorded readings, referring to Fig 6, calcu- terminal tags 29 and 30 as shown in Fig 7. This
late and record the value of the series resistance RS to resistance RB serves as a bleeder resistor.
be used along with the LED.
8 Power-on the bridge rectifier power supply. Check if the
Do the calculations in the space provided in record LED glows at reasonable brightness indicating the
sheet. presence of DC output of power supply.

9 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.3.04 109

 Record sheet for Exercise 1.3.04

1 Type of rectifier : ______________________

2
a) Calculated value of C, for a load of 80mA : ______________________

b) Nearest standard value of C chosen : ______________________

c) Recalculated value of ripple voltage V : ______________________

r(p-p)
for the chosen standard value of C
d) Calculated value of % ripple factor, r : ______________________

3 Table 1

Using meter Using CRO From CRO readings Difference Difference Difference
Load in V using in calculated in calculated
RL Ω
I
L
V
dc
V V V V
out(peak) r(p-p) r(p-p) r(rms)
V
dc dc and mea- and found
mA volts meter and sured value value of
CRO of V %r
r(p-p)

470 W

220 W

4
a) Calculated value of C, for a load of 160mA : _____________________________

b) Nearest standard value of C chosen : _____________________________

c) Recalculated value of ripple voltage V

r(p-p)
for chosen standard value f C : _____________________________

d) Calculated value of % ripple factor r : _____________________________

110 IT & ITES : ICTSM - Exercise 1.3.04

5 Table 2

Label Type of Size of Colour Observed For reasonable brightness of LED

No. LED LED condition
from quick Current through LED Voltage across LED
test (If) (Vf)

(a) Table 3 : Reading taken for red LED FLV117 or equivalent

Observed For reasonable brightness of LED

condition from
quick test Current through LED Voltage across LED

(b) Output DC voltage of Bridge rectifier with ripple filter : Volts

(c) Value of series resistor R for LED :

S

7 Space for calculating R :

S

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.3.04 111

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.05

Identification and testing zener diodes

Objectives: At the end of this exercise you shall be able to
• identify and read specifications of a zener using the data book
• check the condition of the zener using an ohmmeter
• identify the terminals of zener diodes
• check zener action varying the input voltage
• calculate the percentage regulation of the output.

Requirements

Tools/Equipments/Instruments • Resistor 47Ω, 1/2W - 1 No.

• Resistors, 2.2K, 1K, 820Ω, - 1 each.
• Trainees kit
560Ω, 1/4 W
• Power supply, 0-30V,1A - 1 No.
• Patch cords - as reqd.
• DC milliammeter,0 - 50mA - 1 No.
• Lug board (Code:103-06-LB) - 1 No.
Materials/Components • Wire sleeve, yellow - 5 Cms.
• Assorted types of zener diodes - 20 Nos. .
• 12V, 400mw, Zener diode, - 1 No.
1Z12 or equivalent

PROCEDURE

1 Take one of the given zener diodes. Record its label Zener diodes
number and the component code number in Table 1.

Zener resis-
tance in zener
Nominal Zener

Zener current

2 Check and record the working condition of the zener in

% tolerance
Max power
voltage (VZ)

a similar way as you test a rectifier diode.

Package
Number

mode RZ
Type

If you don’t know which terminal (+ve or -ve) of multimeter

( PZ)
(IZ)

is connected to the +ve of the internal battery, Check using

BZX61- 9.1 20mA ±5% 8
another voltmeter and make a mark on your meter.
BZ147 7.5 -- 250mw ±5%,±10% <40W
3 From the polarity marking on the body of the zener and BZ148 8.2V 250mw ±5%,±10% <40W
CZ6 6.8 5mA 200mw ±5%,±10% TO106
from the test carried out at step 2, identify and put a CZ9 9.1 5mA 200mw --do- TO106
yellow sleeve to the cathode terminal of the zener. CAZ3.0 3.0 20mA 400mw ±5%(Caza) 24 DO-7
CAZ5.1 5.1 20mA 400mw ±5%(Caza) 14 DO-7
4 Refer diode data Manual or PTB Table and record the CAZ6.2 6.2 20mA 400mw ±5%(Caza) 3 DO-7
following specifications of the zener diode under test; CAZ9.1 9.1 10mA 400mw ±5%(Caza) 6 DO-7
CAZ12 12 10mA 400mw ±5%(Caza) 10 DO-7
– Nominal zener voltage, V CAZ15 15 5mA 400mw ±5%(Caza) 14 DO-7
Z
ESZ9.1 9.1 200mw ±5% 12 TO106
– % tolerance ESZ12 12 200mw 12 TO106
– Maximum power dissipation, P EZ9-1D10 9.1 28mA ±10% 7
Z(max) OAZ230 12 20mA ±5% 28
– Zener current, I SZ12 12 330mw 12 TO18
Z ZC012 12v 1mA ±5% 45
– Resistance of zener in zener mode, R ZD5012 12v 200m ±10% 2.5
Z ZSD120CF 12V 50mA ±20% 2.5
– Type of package 1N709A 6.2V 24mA ±10% 4
1N716B 12 12mA ±20% 10
5 Get your work checked by your instructor. 1N716 12 12mA ±10% 10
1N759 12 20mA ±10% 30
6 Repeat steps 1 to 5 for atleast five different types of 1N936 9 7.5mA ±5% 20
zener diodes in the given lot. 1ZC12T10 12 15mA ±10% 10
1Z.9-1 9.1 10mA ±10% 30
7 Collect a 12 volt, 400mw (min) zener. Quick check its 1Z12 12 10mA ±10% 30
condition, identify and put a yellow sleeve to its cathode.
Refer data manual and record its specifications in Table
2 of O & T Sheet.

112
8 Wire a test circuit as shown in Fig 1 on a general 11 Get your recorded readings checked by your instructor.
purpose lug board
12 Switch ON PSU. Set V to 25 volts. Measure and
IN
Fig 1 0-10 V record the no-load V in Table 4.
+ -- OUT
VR
13 Connect load resistors of values given in Table 4 across
0-50 mA
470Ω + -- + the output terminals and in ease case measure and
RS mA
record I and output voltage V
L OUT.
-I
+ -Z Switch DC power supply OFF while changing the load
+ + resistors.
PSU
15-25V VIN Z VZ Vout
1Z 12
-- -- 14 Calculate and record the output % load regulation at
-- different loads using the formula,

VIN - VL
-- % Load regulation = × 100
NOTE: DO NOT EXCEED THE UPPER LIMIT OF 25V VL

9 Vary the input to zener V in steps as given in Table where, V is the output voltage on load.
IN L
3 and at each step record the values of V , V and I 15 Get your work checked by your instructor.
R Z Z
in Table 3. After taking readings, switch OFF PSU.
16 Disconnect the circuit and return the components.
10 From the recorded readings in Table 3, calculate and
record the resistance R of the zener, and power
Z
dissipated P for each set of reading taken.
Z

IT & ITES : ICTSM - Exercise 1.3.05 113

 Record Sheet for Exercise 1.3.05

1 Table - 1
Specifications
Label Zener Condition Nominal % tolerance Max.power Zener Zener Type
No. code- from zener Pz current resistance of
number quick voltage Vz Iz Rz package
test

2 Table - 2
Specifications
Code Conditon Zener Condition Nominal % tolerance Max.power Zener Zener Type
No. Code- from zener Pz current resistance of
number quick voltage Vz Iz Rz package
test

3 Table - 3 4 Table - 4

Calculated value of Vin at 25 volts constant

Vin VR Iz Vz Rz Pz RL Vz % load
dc volts volts mA volts Ω Watts volts regulator

open
15
2.2 K Ω
16
1K Ω
17
820 Ω
18
560 Ω
20

25

114 IT & ITES : ICTSM - Exercise 1.3.05

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.06

To construct a zener regulated power supply

Objectives: At the end of this exercise you shall be able to
• calculate the value of a series resistor to be used with a zener for a given load condition
• wire and test the zener regulator power supply.

Requirements

Tools/Equipments/Instruments • Resistor - 1 No.

• Tag board with bridge
• Trainees kit
rectifier, and filter - 1 No.
Materials/Components • Wires sleeve, yellow - 5 Cms.
• Zener diode, - 1 No.

The values of zener diode and the resistor will have to be calculated by the trainee in this exercise before
collecting them.

PROCEDURE

1 In the space provided in Record sheet, design a simple

Fig 1
zener regulator to be connected at the output of the
15 18 20 22 25 29
bridge rectifier with the filter wired on the tag board in R SZ
+
Exercise 9.08. The required output specifications of the LED
zener regulator are given below. +++
Z

1K Ω
26

RB
– Regulated output voltage : 12V DC ±0.5V C
16 23
R SL
– Load current : 27

--
Varying from No-load(0 mA) to 100 mA on full-load. 17 19 21 24 28 30

2 From the design calculations and referring to the diode SOLDER Rsz ACROSS POINTS 20 AND 22
data book, identify at least two types of zeners match- ZENER ACROSS POINTS 22 AND 23
AND SHORT POINTS 23 AND 24
ing the design requirement. Enter the zener type-code
in the O&T sheet.
8 Calculate and record % regulation at 50% and 100% of
3 Get your calculations checked by your instructor.
rated maximum load current.
4 Collect the zener and calculated value series limiting
9 Get your work checked by your instructor.
resistor R . Check the condition of the components.
SZ
5 Connect the series resistor, R and zener diode to the While doing the zener regulator design
SZ
power supply wired on the tag board as shown in Fig 1. calculations, the additional current through
LED was not considered. This will not adversely
6 Recalculate and replace the value of the current limiting
affect the design if the chosen zener and series
series resistor R , used along with the output indica-
SL resistor wattage ratings are slightly over rated.
tor LED.
7 Test and record the regulated output voltage V at
OUT
No-load, 50% of rated full load and at 100% rated full
load .

Use a suitable value and wattage rheostat to

load the output of power supply to 100mA.

115
 Record Sheet for Exercise 1.3.06

1 a) Space for design calculations of simple zener regulator

b) Specifications of zener diode chosen :

c) Specification of series resistor chosen :

2 Space for recalculation of the current limiting resistor R for the LED
S

Load Regulated O/P % load

V volts regulation
out
50%

100%

(Trainee) (Instructor)

116 IT & ITES : ICTSM - Exercise 1.3.06

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.07

Identify, find specifications and quick test transistors

Objectives: At the end of this exercise you shall be able to
• identify a transistor from its type-number the following informations referring to a data book;
(a) Silicon or Germanium (b) PNP or NPN (c) Package type (d) Base, Emitter,Collector pins.
• test the condition of a given transistor using ohmmeter.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Assorted type of transistors - 20 Nos./batch
• International transistors data book - 1 No./batch • Sleeve wires of Red,Yellow,
• Ohmmeter - 1 No. Blue and Black colours - 10 cm each

PROCEDURE

TASK 1: Identifying transistor type and leads, referring to data manual

1 Take any one transistor from the given assorted lot,

enter its label number and transistor type number in
Table 1 of record sheet.
2 Refer to transistor data manual and find and record the
following details of the transistor in Table 1 of record
sheet.
– Whether silicon or germanium
– Whether NPN or PNP
– Type of packaging or case outline (Example:
TO5,TO7 etc.) Collector - Yellow colour sleeve
3 From the type of package recorded, refer to Chart 1 Shield - Black colour sleeve
given at the end of lesson1.3.07 or the transistor data
manual and draw the pin diagram indicating base, In some power transistors, the metal body
emitter and collector for the transistor, in Table 1 of itself will be the collector. In such cases mark
record sheet. ‘C’ on the metal body using a pencil. All
transistors will not have shield pin.
4 Put sleeves of suitable length, as shown in Fig 1, to the
identified pins of the transistor using the colour scheme 5 Repeat steps 1 to 4 for atleast ten transistors of different
given below; types in the given lot and get your work checked by your
Base - Blue colour sleeve instructor.
Emitter - Red colour sleeve

TASK 2: Find Specifications of Transistors

1 Take any one of the transistors used in task-1. Enter – Maximum permissible collector-emitter voltage, VCE
its label number and type number in Table-2 of record (Max.)
sheet.
– Maximum permissible collector-base voltage, VCB
2 Look for the chosen transistor type number in the given (Max.)
transistor data manual and record the following speci-
fications in Table-2 of record sheet. – Maximum permissible collector-current, IC (Max.)

– Maximum permissible emitter-base voltage, VEB – Typical current gain, bdc or HFE
(Max.) – Typical use or application
117
 4 Repeat steps 1 to 3 for atleast 8 transistors of different
If minimum value of bdc is given in the data
package type and ratings.
manual, multiply it by 2 to get typical value of
bdc. 5 Get your work checked by your instructor.
The recorded data in this exercise will relieve you from the
3 Find at least one European, one USA and one Japa-
need of an exclusive transistor data book during the
nese equivalents for the chosen transistor and record in
training.
Table-2.

TASK 3 : Testing transistor junctions using ohmmeter

1 Identify which terminal of the ohmmeter being used is

connected to the +ve terminal of the internal battery of
the meter. Set the meter range to Rx100Ω.
Ohmmeters in very low ohms range can produce excessive
current/voltage and may damage low power transistors
while testing.
2 Take a transistor whose pins are identified and sleeved
at Task 1. Depending on whether the chosen transistor
is NPN or PNP, clip/hold the +ve or -ve of the meter prod
to the base of the transistor as shown in Figs 2a and 2b.
3 Clip the other meter prod to the emitter. Check if the
base-emitter junction diode of transistor shows low
resistance (few tens of ohms) or very high resistance
(few tens of kiloohms). Record your observation in Table
1 of record sheet.
4 Reverse the polarity of the prod connected across the
base-emitter and check if the base-emitter junction
diode of transistor shows low resistance or very high
resistance. Record your observation in Table 1 of record
sheet.
5 From the recorded observations in steps 3 and 4, and
referring to the table given below, conclude and record,
the condition of the base-emitter junction diode of the If the resistance of the junction measured in
transistor as GOOD, open or shorted in Table 1 of both directions is high, in addition to the
record sheet. condition of the junction given in table, one
other possibility is, your identified base pin
may be wrong. You may be measuring
resistance across emitter-collector. In case of
doubt, recheck the identified pins of the
transistor and repeat steps 2, 3 and 4.

Resistance of P-N Resistance of P-N Condition of P-N

junction with meter junction with meter junction
prods in one direction in reversed direction
LOW VERY HIGH GOOD
LOW LOW SHORTED
VERY HIGH VERY HIGH OPEN(See note above)

6 Repeat steps 2,3,4 and 5 and check the condition of the In a good transistor the resistance between the
base-collector junction diode of the transistor. emitter and collector will be very high. A low
7 Measure the resistance across the emitter-collector resistance indicates that the transistor is leaky.
and record the observation as V-HIGH (> 1MΩ) or LOW
(< 500Ω).

118 IT & ITES : ICTSM - Exercise 1.3.07

8 Clip the meter across the emitter-collector with correct
polarity as shown in Fig 3. Touch the base-collector
with moist fingers as shown in Fig 3 and check if the
resistance shown by the meter decreases indicating
that the transistor is turning ON. Record your observa-
tion as YES or NO in Table 1 of record sheet.
9 From the observations recorded at steps 5,6,7 and 8,
give your conclusion on the overall condition of the
transistor under test.
10 Repeat steps 1 to 9 for atleast ten more transistors of
different types and get it checked by your instructor.

IT & ITES : ICTSM - Exercise 1.3.07 119

120
Record Sheet for Exercise 1.3.07

Table - 1

Label Transistor Silicon/ NPN/ Type of Pin diagram Junction Condition Junction Condition Resistance Turn-ON Condition
No. Type- Germa- PNP package In one In reverse of B-E In one In reverse of B-C across test result of
number ium direction direction junction direction direction junction emitter- OK? transistor
collector Yes/No Fit/Unfit

Sample BC107 Silicon NPN TO18 Low Very high Good Low High Good Veryhigh Yes Fit

IT & ITES : ICTSM - Exercise 1.3.07

 Table - 2: Transistor specifications/data

Label Transistor VEB (Max) VCE (Max) VCB (Max) IC(Max) bdc or HFE Use/ Equivalents
No. Type Number typical application European USA Japan

Sample BC108 5V 20V 30V 100mA Min. 120 Low current General BC107 2N929 ----
Typ: 240 purpose Amplifiers

IT & ITES : ICTSM - Exercise 1.3.07

(Trainee) (Instructor)

121
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.08

Find & Plot static characteristics of a transistor amplifier

Objectives: At the end of this exercise you shall be able to
• forward-bias a given PNP/NPN transistor
• measure and plot the input characteristics of a CE amplifier
• measure and plot the output characteristics of a CE amplifier
• find HFE of a transistor using characteristic curves.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Tag board code no.:110-03-TB - 1 No.
• Regulated DC dual Power supply - 1 No. • Transistors, SL 100, SK 100 - 1 each.
• DC milliammeter, 0-100mA - 1 No. • Resistors
• DC microammeter, 0-500mA - 1 No. 47KΩ, 1/4 - 1 No.
• DC millivoltmeter, 0-1000mV - 1 No. 120Ω, 1/4 - 1 No.
• Regulated DC dual power supply - 1 No. 10K, 1/4W - 1 No.
(0-30V, 0-30V - 1 amps) - 1 No. 3.3K, 1/4W - 1 No.
120Ω, 1/4 - 1 No.
1 K Pot, linear - 1 No.
• LED, Red colour - 1 No.
• Hook up Wires and patch cords - as reqd.

PROCEDURE

TASK 1: Forward Bias a given transistor

1 Take one of the given transistors. Refer data book and 6 Using the tested transistor, referring to the circuit at Fig
identify the type of transistor (NPN or PNP), type of 3 of record sheet wire a simple test circuit on the tag
package and its pin layout. Record the details in Table board.
1a of record sheet.
7 Use the outputs of a dual power supply for V1 and V2. Set
2 Carryout quick test and turn-on tests to confirm the the levels of V1 and V2 as given in Serial No.1 of Table1b
good working condition of the given transistor. Record in record Sheet. Check if the LED glows and record your
checked condition in Table 1a of record sheet. observation in the Table.

Take a fresh transistor and repeat step 2, if the 8 From the set values of V1 and V2 and the recorded glow
given transistor is found UNFIT. or no-glow of LED, complete the sentence given in the
remarks column at Table 1(b) of record sheet.
3 In Fig 3 given in record sheet, mark an arrow indicating 9 Repeat steps 7 and 8 for the condition given in Table 1(b)
the type of transistor. Mark the polarities of the power and 3 of Table1b in record sheet.
supplies V1 and V2 such that the transistor is forward
biased. 10 Get your work checked by your instructor.

4 Calculate and write the values of VRB, VBE and IB in Fig 11 Repeat steps 1 to 10 for the other given transistor.
3 of record sheet. Record your observation in the Tables 2a and 2b
provided in the record sheet.
5 Get your marked polarities and values of VRb, VBE and
IB checked and approved by your instructor.

TASK 2: Measure and plot input characteristics or V versus I characteristics of a CE amplifier

BE B

1 Take the NPN transistor used in task-1. Record the 2 Identify the transistor leads and put sleeves following
details and condition of the chosen transistor in table 3 the colour code.
of record sheet.
3 Refer Fig 1 and construct the test circuit.

122
 In this exeperimental setup, for the given transistor , you 7 Set VBE = 0 volts by adjusting the pot. Set VCE to 6 volts.
will observe the variation of IB for variations in VBE. This
8 Repeat step 6 and record readings in Table 5 of record
is referred to as the input characteristics of transitor.
sheet.
4 Set the DC supply VBB to 6 volts and adjust 1K pot such
9 Set VBE = 0 volts. Set VCE to 12 volts.
that VBE = 0V.
10 Repeat step 6 and record the readings in Table 6 of
record sheet.
11 Get your recorded readings checked by your instructor.
12 From the recorded readings in Tables 2, 3 and 4 of
record sheet, plot the input characteristics curves (VBE
versus IB) for the different sets of readings taken with VCE
at 0, VCE at 6V and VCE at 12 V.

Refer Lesson 1.3.08 for sample input characteris-

tic curves.

13 Get the graphs plotted, checked by your instructor.

5 Adjust the DC supply for VCC to 0 volts such that VCE
= 0 volts.
6 Vary the position of 1 K pot to set VBE at different levels
as given in Table 4 of record sheet. At each setting
record value of base current IB.

TASK 3: Find and plot output characteristics or V versus I characteristics of a CE amplifier

CE C

1 As shown in Fig 2 modify the wired test circuit wired in

Task-1 to observe variations in IC for variations in VCE
(output characteristics) of the transistor for different
values of IB.
2 Set VCC to 0V such that VCE = 0V.
3 Adjust the supply VBB such that IB = 100 μA.
4 Vary VCC such that VCE is set at values given in Table
7 of record sheet. At each setting record the value of
IC.
5 Set IB to values 200 μA, 300 μA, 500 μA and at each
setting repeat step 4. Record the readings in Table 8,
9 and 10 of record sheet respectively. 9 Get the plotted graph checked by your instructor.
6 Get your recorded readings checked by your instructor. 10 From the graph plotted/recorded readings, find the dc
7 From the recorded readings in Tables 6, 7 and 8, plot the current gain b of the transistor in the interval of IB
output characteristics graph (VCE versus IC) for different = 100μA and IB = 300μA at VCE of 6V. Record the
sets of readings taken at IB = 100μA, IB = 200μA,IB calculation and result in the record sheet.
= 300μA andIB = 500μA.
Refer of Lesson 1.3.08 in case of difficulty.
8 From the recorded readings in Tables 7, 8,9 and10, find
bdc of the transistor at different VCE voltages and tabulate 11 Compare the calculated value of b in step 10 and value
the readings in Table 11 of record sheet. noted from the data book at step 1. Record the differ-
ence.
12 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.3.08 123

 Record Sheet for Exercise 1.3.08

FOR TASK 1
For Ist Transistor
1 Table - 1a

Transistor type number

NPN/PNP

Pin layout

Condition of transistor

2 Table - 1b

Sl.No. Condition LED glows? (YES/NO) Remarks

1 V1 = 0V LED does not glow because the transistor is not ON. This is
V2 = 6V because the _____________ junction is not forward biased,
although the BC junction is correctly biased.
2 V1 = 3V LED glows because the transistor is ON. This is because the
V2 = 6V _____________ junction is forward biased and the base -
collector junction is reverse biased.
3 V1 = 3V LED does not glow because the transistor is not ON. This is
V2 = 0V because the base - collector junction is not _______________
biased although the base - emitter junction is forward biased.

For 2nd Transistor

1 Table - 2a

Transistor type number

NPN/PNP

Pin layout

Condition of transistor

2 Table - 2b

Sl.No. Condition LED glows? (YES/NO) Remarks

1 V1 = 0V LED does not glow because the transistor is not ON. This is
V2 = 6V because the _____________ junction is not forward biased,
although the B-C junction is correctly biased.
2 V1 = 3V LED glows because the transistor is ON. This is because the
V2 = 6V base-emitter junction is _______________ and the base -
collector junction is _______________.
3 V1 = 3V LED does not glow because the transistor is not ON. This is
V2 = 0V because the base - collector junction is not _______________
biased although the base - emitter junction is forward biased.

124 IT & ITES : ICTSM - Exercise 1.3.08

TASK 2: Input characteristics of transistor

1 Table - 3

Type Number b or HFE Condition

of transistor (typical) from quick tests

2 Table - 4

VCE set at 0 volts, constant

VBE 0 200 300 400 500 600 700

in mV mV mV mV mV mV mV
IB
mA

3 Table - 5

VCE set at 6 volts constant

VBE 0 200 300 400 500 600 700

mV mV mV mV mV mV
IB
mA

4 Table - 6

VCE set at 12 volts constant

VBE 0 200 300 400 500 600 700

mV mV mV mV mV mV
IB
mA

5 Graph 1
[Input characteristics]

IT & ITES : ICTSM - Exercise 1.3.08 125

TASK 3: Output characteristics of transistor

6 Table - 7

IB set at 100 mA constant

VCE 0.2V 0.4V 0.6V 0.8V 1V 2V 3V 4V 5V 6V 7V 8V

IC

7 Table - 8
IB set at 200 mA constant

VCE 0.2V 0.4V 0.6V 0.8V 1V 2V 3V 4V 5V 6V 7V 8V

IC

8 Table - 9

IB set at 300 mA constant

VCE 0.2V 0.4V 0.6V 0.8V 1V 2V 3V 4V 5V 6V 7V 8V

IC

9 Table - 10

IB set at 500 mA constant

VCE 0.2V 0.4V 0.6V 0.8V 1V 2V 3V 4V 5V 6V 7V 8V

IC

10 Table - 11

11 Graph 1
Current gain, Bdc at, [Output characteristics]

VCE IB = 100 mA IB = 200 mA IB = 300 mA IB = 500mA

1V

2V

4V

6V

Space for other entries

(Trainee) (Instructor)

126 IT & ITES : ICTSM - Exercise 1.3.08

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.09

Find Voltage gain,Power gain, Input /Output impedance and Phase

relationship of a Common Emitter amplifier
Objectives: At the end of this exercise you shall be able to
• measure the voltage gain of a CE amplifier
• measure the input and output impedance of a CE amplifier
• measure the power gain of a CE amplifier
• measure the phase relationship between input and output.

Requirements

Tools/Equipments/Instruments • Capacitor, 100 μF/25 V,electrolytic,

• Trainees kit - 1 No. axial - 1 No.
• Oscilloscope, 20 MHz, Dual trace - 1 No. • Capacitor, 25 μF/25 V,electrolytic,axial - 2 Nos.
• AF Signal generator - 1 No. • Potentiometer, 10 KΩ, carbon - 1 No.
• Regulated DC power supply,0-30V,1A - 1 No. • Resistors 1/4W, carbon
• DC microammeter, 0-500μA - 1 No. 120Ω - 1 No.
• DC milliammeter, 0-30mA - 1 No. 470 Ω - 1 No.
1 KΩ - 1 No.
Materials/Components 1.2KΩ - 1 No.
• Tag board - 1 No. 5.6KΩ - 1 No.
• Transistor, SL100 or equivalent - 1 No. • Hook-up wires - 20 Cms.
• Diode 1N914/OA79 - 1 No. • Rosin-cored solder, 22 gauge - 10 Cms.

PROCEDURE

TASK 1: Current gain A of CE amplifier

i
1 Construct the circuit of a CE amplifier as shown in
Fig 1.
2 Apply VCC. Measure and Record IC and IB in Table 1 of
record sheet.
3 Calculate and record the values of current gain Ai of the
amplifier. Get it checked by your instructor.

TASK 2: Voltage gain A of the amplifier

V

1 Construct a CE amplifier as shown in the schematic 3 Set the output of the Sig. Gen. to 1 KHz, sine wave.
diagram at Fig 2. Adjust the signal generator output level such that the
output wave-form seen on CRO is maximum and is
2 Get the wired circuit checked by your instructor before
undistorted. Get it checked by your instructor.
applying voltage to the circuit.

127
 4 Measure the peak-to-peak values of input ac Vin and
output ac Vout of the circuit. Record your readings in
record sheet.
5 From the recorded readings, calculate and record the
voltage gain AV of the amplifier.
6 Get the readings checked by your instructor.

TASK 3: Measuring the input and output impedance - Calculating power gain A of the amplifier
P

1 Using CRO, measure the input voltage(peak) VX at point At this stage DON’T change the input signal level Vin to
X and VY at point Y. Record your readings in the record the amplifier.
sheet.
6 Adjust 10K pot such that the output level Vout seen on
2 Find the input current iin using Ohm’s law as given CRO, shows half the value of Vout measured and
below, recorded at step 4.

V X – VY 7 Switch OFF DC supply to the circuit. Remove the pot

iin = . from the circuit without disturbing the adjusted value of
R1
the pot. Measure the adjusted resistance value of the
3 Calculate and record the input impedance Zin of the pot. Record this value as the output impedance Zout of
amplifier using the formula, the amplifier in the record sheet.
8 From the recorded readings, calculate the power gain
Vin
Input impedance, Z in = . of the CE amplifier using the formulae,
iin

Vin is nothing but the voltage VY measured at step 1. 2

Vin
Input power to the amplifier, Pin =
4 Measure the value of amplified ac Vout(p-p) at the output Z in
of the amplifier and record in the record sheet.
Vout 2
5 Connect temporarily a 10 K pot across the output of the Output power of the amplifier, Pout =
amplifier as shown in Fig 3. Z out

Pout
Amplifier power gain A P =
Pin

Pout
Amplifier power gain A P in decibels (dB) = 10 log .
Pin

9 Calculate amplifier power gain Ap from the calculated

values of Ai and Av at tasks 1 and 2. Record the power
gain Ap of the amplifier.
10 Get your work checked by your instructor.

128 IT & ITES : ICTSM - Exercise 1.3.09

TASK 4 : Input-output phase relationship

1 Modify the circuit as shown in Fig 4.

2 Adjust the signal generator output for maximum
undistorted Vout.
3 Connect Ch-1 of CRO at the input point X of the circuit
and Ch-2 at the output point Z of the circuit as shown
in Fig 4.
4 Switch ON DC supply to the circuit. Observe and
sketch the wave-form at the input and output of the
amplifier in the record sheet.
If a store button is available on the CRO use it while
sketching wave-forms.
5 Give your remarks on the phase relationship between
the input and output wave-forms in the space provided
in the record sheet.
7 Desolder and remove only R1, D1 and R2. Rest of the
6 Get the readings and sketched wave-forms checked by circuit component should not be removed as the same
your instructor. circuit is required in Ex.1.3.10.

Retain the wired CE amplifier circuit as the same is required to carry out exercise 1.3.10.

IT & ITES : ICTSM - Exercise 1.3.09 129

 Record sheet for Exercise 1.3.09

TASK 1: Current gain Ai of CE amplifier

1 Transistor used : ______________ Typical bdc : ______________

2 Table - 1
Collector current IC Base current IB Current gain Ai

TASK 2 : Voltage gain Av of CE amplifier

1 Remarks of Instructor on correctness and neatness of the wired circuit:

Very good Good Satisfactory Poor/Redo

2 Vin(peak-to-peak) : ___________ Vout(peak-to-peak) : ___________ Calculated AV : ___________

(Refer Fig -2) (at point Z of circuit)

TASK 3 : Input impedance Zin, output-impedance Zout and power gain Ap of CE amplifier

1 VX(peak-to-peak) : ___________ VY(peak-to-peak) : ___________ Calculated iin : ___________

(at point Y of circuit) (at point X of circuit)
2 Calculated input Impedance, Zin : ___________ Ω
3 Vout (Peak-to-peak) : ___________
(at point Z of circuit)

4 Half power point of Vout(peak-to-peak) : ___________

5 Output impedance, Zout : ___________ Ω
(Refer Step 6 of Task 2)
6 Input power to the amplifier, Pin : ___________
7 Output power of the amplifier, Pout : ___________
8 Amplifier power gain, Ap : ___________
9 Amplifier power gain Ap in dB : ___________ dB
10 Amplifier power gain Ap = Ai . Av : ___________

TASK 4 : Phase relationship of input and output in a CE amplifier

Note: Make only a rough pencil sketchs of wave-forms.

Input wave-form Output wave-form Remarks on

(at point X of circuit) (at point Z of circuit) input-output
phase relationship

(Trainee) (Instructor)
130 IT & ITES : ICTSM - Exercise 1.3.09
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.10

Construct and test a Common Collector or Emitter follower amplifier

Objectives: At the end of this exercise you shall be able to
• construct an emitter follower amplifier and measure
– current gain, Ai – output impedance,Zout
– voltage gain, AV – power gain, AP
– input impedance,Zin – input - output phase relationship.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit • Tag board - 1 No.
• DC microammeter 0-500 μA - 1 No. • Transistor, SL100 or equivalent - 1 No.
• DC milliammeter 0-1 mA - 1 No. • Resistors, 1/4 W, carbon
• Regulated power supply, - 1 No. 120 Ω - 1 No.
0-30V, 1A 100 KΩ - 1 No.
• A.F Signal generator - 1 No./batch.
• Preset, 470Ω - 1 No.
• Oscilloscope, 20 MHz - 1 No./batch.
• Capacitors, 0.47 μF - 2 Nos.

PROCEDURE

TASK 1: Finding Current gain and voltage gain

1 Check the given components and wire an emitter

follower circuit as shown in Fig 1.

2 Measure and record the values of IB and IE, in Table 1 of

the record sheet. Assuming IC » IE, calculate and record
the b of the transistor using the formula, Refer lesson 1.3.10 for other formulae.
4 Modify the wired circuit to that shown in Fig 2. Get the
correctness and neatness of the wired circuit checked
by your instructor.
3 Using the value of IE and b from step 2, calculate and 5 Connect the signal generator to the input of the emitter
record the theoretical values of voltage gain Av, input follower amplifier. Set the signal generator output to
impedance Zin, output impedance Zout and current gain sine wave, 1 KHz.
Ai of the amplifier.
6 Adjust the signal generator output level such that the
AC input Vin(p-p) = 500 mV. Measure and record the
To calculate the value of r'e use the formula,
corresponding output Vout(p-p) of amplifier in record sheet.
7 From the measured values of Vin and Vout, calculate and
record the voltage gain AV of the circuit.
131
8 Compare the values of calculated voltage gain Av of the 9 Get your work checked by your instructor.
amplifier in step 3 and that found in step 7. Record the
difference in record sheet.

TASK 2: Measuring input and output impedance of emitter follower

1 Set the output of the signal generator to sine wave,

1 KHz, 500 m Vin(p-p) and record Vin and Vout levels.
2 Measure voltages VXG and VYG on either side of the 1K
resistor. Record readings in the record sheet.
3 From the recorded values of VXG and VYG, calculate the
input signal current iin to the amplifier using Ohms law
as given below,

V XG - VYG
iin =
1KΩ

4 From the values Vin and iin, calculate and record the 8 Measure the adjusted value of the preset and record it
input impedance Zin using the formula as the amplifier’s output impedance Zout in record sheet.
Vin 9 From the values recorded the calculate and record,
Z in = current gain Ai, and power gain AP of the amplifier, using
Iin
the formulae
10 Get your work checked by your instructor.
5 Connect a 470Ω preset across the output of the
amplifier as shown in Fig 3. Keep the preset in the
maximum resistance position before switching ON DC Z in
supply to the circuit. Ai = A V
RE
Since there is no limiting resistor in the collector, if the 2
preset is set at zero or low resistance heavy current Vin
Pin =
may damage the transistor. Z in
6 Adjust the pot until Vout is half the value measured at Vout 2
Step 1. Pout =
R out
Do not adjust the output level of sig. gen. set at step 1 Pout
Power Gain of amplifier A P =
of this task. Pin
7 Switch OFF dc supply to the circuit. Take out the preset Pout
Power Gain AP in decibel = 10 log
from the circuit without disturbing its adjusted value. Pin

TASK 3 : Phase relationship between input and output of emitter follower

1 Modify the circuit as shown in Fig 4. 4 Switch ON DC supply to the circuit. Observe and
2 Adjust the signal generator output for maximum sketch the wave-form at the input and output of the
undistorted Vout. amplifier in the record sheet.

3 Connect Ch-1 of CRO at the input point X of the circuit If a store button is available on the CRO use it while
and Ch-2 at the output point Z of the circuit as shown sketching wave-forms.
in Fig 4.

132 IT & ITES : ICTSM - Exercise 1.3.10

 5 Give your remarks on the phase relationship between
the input and output wave-forms in the space provided
in the record sheet.
6 Get the readings and sketched wave-forms checked by
your instructor.

IT & ITES : ICTSM - Exercise 1.3.10 133

 Record sheet for Exercise 1.3.10

TASK 1
1 Table - 1
2 Values calculated using circuit component
IB IE Current gain values
Ai = IE/IB»b
Av Zin Zout Ai r'e

3 Instructor's remarks on correctness and neatness 4

of wired circuit (a) Measured value of Av
Very good Good Satisfactory Poor/Redo
Frequency set to 1 KHz

Vin(p-p) V out(p-p) AV

500 mv

(b) Difference between calculated (at spte-3) and

measured value of Av (at step-7):

TASK 2

1 Table - 2

Frequency set to 1 KHz

Vin(p-p) V out(p-p) VXG VYG iin Input impedance Output impedance
Zin of amplifier Zout of amplifier

500 mV

2 Current gain Ai using the formula Ai = Av(Zin/RE) : __________

3 Power gain Ap of emitter follower/CC amplifier : __________
4 Power gain Ap of emitter follwer/CC amplifier in dB : __________

TASK 3
1 Note: Make rough pencil sketches of wave-forms

Amplifiers Amplifiers Remarks on input-output

input wave-form output wave-form phase relationship

(Trainee) (Instructor)
134 IT & ITES : ICTSM - Exercise 1.3.10
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.11

Construct and test a common base amplifier

Objectives: At the end of this exercise you shall be able to
• construct a common base test amplifier and measure,
– current gain, α of the amplifier
– voltage gain AV of the amplifier
– input-impedance of the amplifier
– output-impedance of the amplifier
– power gain AP of the amplifier.

Requirements

Tools/Equipments/Instruments • Resistors, 1/4 W, carbon

1 KΩ - 1 No.
• Trainees kit
1.2 KΩ - 1 No.
• DC milliammeter, 0-10mA - 2 Nos.
2.2 KΩ - 1 No.
• Regulated power supply, 12V, 100mA - 1 No.
3.3 KΩ - 1 No.
• Oscilloscope, 20 MHz - 1 No.
6.8 KΩ - 1 No.
Materials/Components 10 KΩ - 2 Nos.
• Potentiometer 10 KΩ, carbon - 1 No.
• Tag board - 1 No.
• Electrolytic capacitors 25V,
• Transistor, SL 100 - 1 No.
25 μF - 2 Nos.
100 μF - 1 No.

PROCEDURE

TASK 1: Measuring a, Av, Zin and Zout in CB amplifier.

1 Test the given components and construct a common

base amplifier as given in Fig 1. Use the value of a found in step 3. Find the
value of r'e using the formula, r'e = 25mV/IE.

2 Switch ON DC supply to the circuit. Measure and

record the dc voltage levels of VBG, VBE, VCB and VCE. 5 Modify the circuit as shown in Fig 2.
From the readings, conclude whether the transistor is
6 Set the output of the Signal generator to Sine wave,
working or not.
1KHz at 500mV. Measure and record Vin and Vout of the
3 Record the values of input current IE and output current amplifier. Calculate and record the voltage gain AV of the
IC. Calculate and record the current gain a of the amplifier.
common base amplifier.
7 Measure and record the input impedance Zin of the
4 From the component values given in Fig 2, referring to common base amplifier in the same way as found in
lesson 1.3.11, calculate and record values of, input common emitter/common collector amplifiers.
impedance Zin, output impedance Zout, voltage gain Av.

135
8 Measure and record the output impedance Zout of the 10 Compare the calculated readings at step 4 and the
common base amplifier in the same way as found in actual values measured. Record the difference in record
common emitter/common collector amplifiers. sheet.
9 From the above recorded readings find and record the
power gain of the common base amplifier.

TASK 2:- Phase relationship between input and output

1 Find the phase relationship between input and output of 3 Get your work checked by your instructor.
the common base amplifier in the same way as was
done for CE and CC amplifiers. You can use the recorded comparative table as a ready
reference.
2 Complete the comparative table given in record sheet
using the tabulated results of Exercises 1.3.08, 1.3.09
and this exercise.

136 IT & ITES : ICTSM - Exercise 1.3.11

 Record sheet for Exercise 1.3.11

TASK 1
1 Current gain Ai or a of CB amplifier

VBG VBE V CB VCE Condition IE IC Current gain

of transistor Ai (or) a

2 Calculated values using given circuit component values:

r'e Zin Zout Av Ap

3
Frequency set to 1 KHz , sine wave

Vin V out Voltage gain Input impedance Output Impedance Power gain Power gain
AV Zin Zout AP AP in dB

4 Input/output phase relationship

Make only rough sketches of wave-forms using pencil.

Amplifiers Amplifiers Remarks on input-output

input wave-form output wave-form phase relationship

5 Comparative table of CE, CC and CB amplifiers using tabulated results of Exercises1.3.08, 1.3.09 & 1.3.10
Common emitter Common collector Common base
or emitter follower
Current gain
Voltage gain
Power gain
Input impedance
Output impedance
Phase relationship
between input & output
(Trainee) (Instructor)
IT & ITES : ICTSM - Exercise 1.3.11 137
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.12

Testing of JFET, JFET amplifiers

Objectives: At the end of this exercise you shall be able to
• find the specifications of a given JFET using data manual
• identify the terminals of the given JFET
• quick test N-channel JFET
• construct a voltage amplifier using a JFET
• find the gain of JFET amplifier
• find and plot the gain of the amplifier at different frequencies.

Requirements

Tools/Equipments/Instruments • Capacitors
5.6 nF, Disk - 1 No.
• Trainees kit
270 nF, Disk - 1 No.
• Regulated d.c power supply,
6.8 μF/24V, electrolytic - 1 No.
24 Volts/1 A - 1 No.
• Resistors, carbon film, 1/4w
• Function generator - 1 No./Batch of 2
10 KΩ - 1 No.
• 100 MHz Oscilloscope - 1 No./Batch of 4
12 KΩ - 1 No.
Materials/Components 47 KΩ - 1 No.
1 MΩ - 1 No.
• Assorted types of N-channel
• Solder, flux - as reqd.
JFET - 4 Nos.
• Hook up wires - 1 Meter.
• Sleeves
Red, Green, Yellow, Black - 4 Nos. One of the given JFET should be a BF 245B or
(each of 10mm length) (in each) BFW 10 or equivalent.

PROCEDURE

TASK 1: Identify the leads of given JFET’s and find specifications of JFET using Data manual

1 Take a JFET from the given assorted lot. Record the – Maximum power dissipation, Pmax
Type number of the JFET and enter it against its label
number in Table 1 of Record sheet. – Package type

2 Referring to data manual/pocket table book, identify – Pin diagram

and record the following important specification of the 3 From the identified package type, identify the leads of
JFET based on its Type Number; the JFET and put sleeves of suitable length to the leads
– Polarity of the device(N-type/P-type) following the colour scheme given below;

– Maximum drain-source voltage, VDS Drain - Red

– Maximum gate-source voltage, VGS Source - Green

– Maximum drain current, ID Gate - Yellow

– Maximum forward gate current, IG Shield - Black

– Pinch-off Voltage(at ID=0), VP 4 Repeat steps 1 to 3 for the remaining JFETS.

5 Get your work checked by your instructor.

138
TASK 2: Quick Testing N channel JFET using ohmmeter

1 Identify the internal polarity of the terminals of the 2 Set the meter to Rx100Ω range. Refer table given below
ohmmeter/multimeter and insert the red prode to the and test the given JFET. Record the readings taken for
meter terminal connected to +ve of internal battery and each JFET in Table 2 of Record sheet.
black prode to -ve of the internal battery.

Measured Resistance

GATE SOURCE DRAIN GOOD FET BAD FET

1 OPEN - Ve + Ve Very Low High/VH

2 OPEN + Ve - Ve Very Low High/VH

3 - Ve OPEN + Ve Very High Low/VL

4 + Ve OPEN - Ve Very Low High

5 - Ve + Ve OPEN High Low

6 + Ve - Ve OPEN Low High

3 From the recorded resistance readings in table 2, give 5 Repeat steps 2 and 3 for the remaining N-channel
your conclusion on the condition of the JFET in the JFET’s and get it checked by your instructor.
Table 2 of Record sheet.
4 Get your work checked by your instructor.

TASK 3:- Construct and test a a.c FET amplifier

1 Refer Fig 1 and construct an AC voltage amplifier using 2 Get the wired circuit checked by your instructor.
a N-channel FET.
3 Power-on wired circuit. Feed input, at 10Khz and level
Construct the circuit on a bread board or on a GPCB. If you from 1mv to 1V in steps of 100mV. Measure the
are wiring the circuit on a GPCB use base for the FET to corresponding output levels by using CRO and record
ensure that it does not get damaged. in Table 3.
4 From the recorded readings at step 3, calculate and
record gain of the amplifier.
5 Get the recorded readings checked by your instructor.
6 Calculate the gain of the amplifier with an input of 400
mV at frequencies 40Khz, 80 Khz, 100Khz, 120 Khz
and at 150 KHz in Table 4 in record sheet.
7 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.3.12 139

 Record Sheet for Exercise 1.3.12

1 Table 1

FET No. Type Polarity VDS VGS ID IG VP Pmax Pin diagram

2 Table 2

FET Gate Source Drain Measured Condition

No. resistance good/bad

open -ve +ve

open +ve -ve
-ve open +ve
+ve open -ve
-ve +ve open
+ve -ve open

3 Table 3 4 Table 4
Input frequency : 10 KHz
Output voltage Input volt
Sl. Input O/R voltage Gain=
No. voltage Input voltage Output voltage
Frequency Gain =
1 100 kHz Input voltage
2 200
3 300 40
4 400 80
5 500 100
6 600 120
7 700 150
8 800
9 900
10 1V

140 IT & ITES : ICTSM - Exercise 1.3.12

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.13

Construct and test a relaxation oscillator using UJT

Objectives: At the end of this exercise you shall be able to
• find the specification of a given UJT
• identify the terminals of UJT
• quick test given UJT
• construct and test relaxation oscillator using UJT
• measure time period and frequency.

Requirements

Tools/Equipments/Instruments • Sleeves (in red,black and blue - 100 cm each.

colour
• Trainee tool kit
• Resistors
• UJT data book - 1 No./batch.
16Ω (½W) - 1 No.
• CRO - 1 No./batch.
330Ω (½W) - 1 No.
Materials/Components 100K (¼W) - 1 No.
• Potentiometer 470K (500mw) - 1 No.
• General purpose PCB - 1 No.
• Capacitor 100mF - 1 No.
• UJTs, 2N 2646 and 2N 2160 - 2 Nos.

PROCEDURE

TASK 1 : Find specifications of UJT, identify and sleeve leads

1 Refer UJT data manual to find and reciord the specification Base 1 - blue
of the given UJTs in Table 1 of record sheet (Column 1
to 7). Base 2-black

2 From the package type of the given UJTs, referring to Emitter - red
the data manual, identify and put sleeves to its leads 3 Get your work checked by the instructor.
following the colour sequence given below;

TASK 2 : Test a UJT using ohmmeter

1 Identify and mark the internal battery polarity at the 3 From the recorded observations, referring to lesson
terminals of the ohmmeter/multimeter used for testing 1.3.13 assess and record the condition of the UJT in
the UJT. Set the meter range to R x 100 or R x 1000 record sheet (Column 8).
ohms.
4 Repeat steps 2 and 3 for other given UJTs.
Very low ohms range can produce excessive current
through the UJT and damage it. 5 Get your work checked by your instructor.

2 For one of the given UJT, test and record the resistance
across the UJT terminals(forward bias/reverse bias)
using the ohmmeter.
Refer lesson 1.3.13 for details of forward/reverse bias.

141
TASK 3 : Construct and test relaxation oscillator using a UJT

1 Test the components to be used for wiring a UJT 4 With the postion of Pot-R1 in one extreme, check,
relaxation oscillator shown in Fig 1. Clean and tin the observe and sketch the waveform across the capacitor
PCB to be used for wiring. (C1) in record sheet.
2 Refer circuit schematic shown in Fig 1 and construct 5 Measure duration of T in the wave form observed at the
the circuit of relaxation oscillator using UJT. Get the emitter (across C1). Calculate and record the frequency
wired circuit checked by your instructor. of oscillations from the measured value of T.
3 Give 12 V DC supply to the circuit. Check and confirm 6 Repeate steps 4 & 5 with the Pot R1 in other extreme
that no circuit components are excessively getting position.
heated-up. If so consult your instructor.
7 From above readings, record the range of frequency of
osciallation of the relaxation oscillator.
8 With the position of pot R1 in minimum resistance
position, check and sketch the waveform at test-point
TP-2 in record sheet.
9 Repeat step 8 with Pot-R1 in maximum resistance
position.
10 Get your work checked by your instructor.

Record sheet for Exercise 1.3.13

1 Table 1

Type Device IP IV RBBO h Package Condition of

type UJT
1 2 3 4 5 6 7 8

2 Waveforms at TP1 and TP2 (ii) Keeping pot R1 in maximum resistance position.

(i) Keeping pot R1 in minimum resistance position.

AT TP1 AT TP1

AT TP2 AT TP2

142 IT & ITES : ICTSM - Exercise 1.3.13

Space for recording additional information

IT & ITES : ICTSM - Exercise 1.3.13 143

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.14

Identify and test SCR, TRIAC and DIAC

Objectives: At the end of this exercise you shall be able to
• identify the specifications of SCR referring to data book
• identify the anode, cathode, gate pins of the given SCR
• conduct quick-test to find the condition of the given SCR
• test SCRs using SCR test-jig
• find the specifications of a given TRIAC using data manual
• identify the terminals of the given TRIAC
• find VGT and IGT of a TRIAC in different triggering modes
• find the specifications of a given DIAC using data manual
• test a given DIAC.

Requirements

Tools/Equipments/Instruments • General purpose PCB - 1 No.

• LED
• Trainees tool kit
Green - 1 No.
• Dual DC supply - 1 No./batch.
Red - 1 No.
0-30V, 1 Amp
• Resistors
• DC milliammeter, 0 to 5 mA - 1 No./batch.
470 Ohms, ¼W - 1 No.
• Isolation transformer 230V 50Hz - 1 No./batch.
1Kilo Ohms, ½W - 2 Nos.
• Variac - 1 No./batch.
• Potentiometer 1kilo ohm, ¼W - 1 No.
• CRO dual trace 20 MHz - 1 No./batch.
• Single pole single way switch - 2 Nos.
• International SCR data book - 1 No./batch.
• Sleeve wires Red, Blue, -
Materials/Components Yellow, Black - 10 cms each.
• Diac DB3 or equivalent - 1 No.
• Assorted type of SCRs - 20 Nos.
• Resistor 1K, ½W - 1 No.
• Triac BT136, 2N6071 or
equivalent - 1 No. each.

PROCEDURE

TASK 1: Identify SCR type and leads referring to data manual

1 Pick any one SCR from the asorted lot. Enter the picked Anode : RED sleeve
SCR label number and its Code/type number (printed
Cathode : YELLOW sleeve
on the SCR) in Table 1 of record sheet.
In some power SCRs, the metal case itself will act as
2 Draw a pencil sketch of the SCR pin diagram. Identify
anode. In such a case mark ‘A’ on the case using a pencil
and record the Anode, Cathode and Gate pins of each
or put a RED colour dot using colour marker pen.
SCR referring to the data manual.
5 Get your work checked by your instructor.
3 Put sleeves of suitable length to the identified pins of the
SCR using the colour scheme given below: 6 Repeat steps 1 to 5 for atleast five different types of
SCRs from the assorted lot.
Gate Pin : BLUE sleeve

TASK 2: QUICK test SCRs using an ohmmeter

1 Pick anyone SCR used in Task 1 whose terminals are 3 Test the picked SCR following the table below and
identified. record the measured resistances in table 1.
2 Identify and mark the internal battery polarity at the – Between Anode - Cathode
terminals of the ohmmeter/multimeter (in ohms range)
to be used for Quick-testing SCRs. Select Rx100 Irrespective of polarity
range.

144
 – Between Gate - Cathode – Connect positive lead of multimeter to the anode and
the negative lead to the cathode. Measure and
(i) Forward biased
record resistance.
(ii) Reverse biased
– Short anode and gate of SCR using a piece of wire.
– Between Gate - Anode Measure and record resistance between Anode and
Irrespective of polarity Cathode.

4 From the recorded readings, record your conclusion – Disconnect the shorted anode-gate, measure and
about the working condition of the SCR. record resistance between Anode and Cathode.

Refer lesson 1.3.14 for assistance in making your conclu- 6 From the recorded readings in step 5 and from the
sion about the condition. knowlege aquired about working of SCR in lesson
1.3.14 conclude the condition (GOOD/ OPEN/
5 For the picked SCR carryout the following steps to SHORTED) of the SCR under test.
check the gating effect of SCRs;
7 Repeat steps1, 3 to 6 for atleast two more SCRs.
– Set multimeter to low resistance range (Rx1 or
Rx10). 8 Get your work checked by your instructor.

TASK 3: Test SCRs using SCR test jig

A SCR test jig whose circuit schematic is shown in Fig 1 4 Refer lesson 1.3.14 and test the given SCR for its
will be given to a batch of trainees by the instructor to test working condition using the SCR testing jig. Record the
SCRs. test result in record sheet.
1 Trace and check if the given test jig is similar to that 5 Repeat steps 3 and 4 to test atleast 3 different types of
given in Fig 1. If it is different consult your instructor for SCRs.
modified steps of this task. 6 Get your work checked by your instructor.
2 Pick any one SCR used in Task 2 of this exercise.
3 Clip the test probes of the jig to A,K G pins/terminals of
the SCR to be tested.

TASK 4: Identify the specifications and leads of a TRAIC

1 Refer to the data manual and identify and record the 3 Get your work checked by your instructor.
specifications of the given Triacs in record sheet.
For package type in which sleeves cannot be
2 Refer data manual and identify the terminals of the given
put, mark the terminals as M1, M2 and G using
Triacs. Put sleeves to the identified leads of the Triac
a permanent marker or 2HB pencil.
following the colour scheme given below;
– Main Terminal-1 (MT1) - Red colour sleeve.
– Main Terminal-2 (MT2) - Blue colour sleeve.
– Gate (G) - Yellow colour sleeve.

IT & ITES : ICTSM - Exercise 1.3.14 145

TASK 5:- Quick test TRIAC using ohmmeter

1 Identify the internal battery polarity of the terminals of 4 From the recorded reading and referring to lesson
the ohmmeter/multimeter and mark it on the meter 1.3.14 record your conclusion about the condition of
using pencil or sketch pen. the traic tested.
2 Set the meter to Rx1 ohms range for testing the Triac. 5 Get your work checked by your instructor.
The Rx1 ohm range is commonly used to carry out quick 6 Repeat steps 3 to 5 for the other given TRIAC.
test on Triacs because it usually provides the necessary
holding current to latch this device into conduction.
3 Pick anyone of the given TRIAC, refer lesson 1.3.14and
test the triac giving suitable bias polarities. Record the
measured resistance in the table provided in the record
sheet.

TASK 6:- Find VGT and IGT of a Triac in different triggering modes

A TRIAC test jig whose circuit is shown in Fig 2 will be given By this, the gate voltage VGT is made negative.
to you by your instructor.
6 Put S1 and S2 to ON position. Vary position of POT R4
1 Connect any one of the given TRIAC in the test jig and slowly, such that the applied - ve gate voltage to triac
get it checked by your instructor. increases. Increase -ve gate voltage until LED-1 just
turn-ON. Measure and record VGT under triggering
mode-II in record sheet.
In this mode, MT1 is +ve and VG is -ve.
7 Continue to increase the -ve gate voltage until LED-2
just turns-ON. Measure and record VGT under triggering
mode-III in record sheet.
In this mode, MT1 is -ve with respect to VG, and VG is -ve.
8 Get your recorded readings checked by your instructor.
2 In the given test jig, keep POT R4 in minimum resistance
9 Put S1 and S2 to OFF position. Set POT R4 to minimum
position. Connect +12V gate voltage to point X.
resistance position. Connect back +12V gate supply to
3 Put S1 and S2 to ON position. Vary position of POT R4 point X.
slowly, such that the applied triac gate voltage in-
By this, the gate voltage VGT and MT1 both are made
creases. Increase gate voltage until LED-1 just turn-
positive bringing back the condition to mode - I.
ON. Measure and record VGT under triggering mode-I in
record sheet. 10 Connect a 0-50 mA d.c milliammeter in series with the
gate circuit as shown in fig 2 to measure gate current
In this mode, MT1 is +ve and VG is +ve.
IGT.
4 Continue to increase the gate voltage until LED-2 just
11 Repeat steps 3 to 9 and measure the gate trigger
turns-ON. Measure and record VGT under triggering
current (IGT) in all the four different triggering modes.
mode-IV in record sheet.
Record values of gate current IGT in table.
In this mode, MT1 is -ve with respect to VG, and VG is +ve.
12 Compare the experimentally found values of VGT and
5 Put S1 and S2 to OFF position. Set POT R4 to minimum IGT in different modes with the manufacturers specifica-
resistance position. Connect -12V gate supply to point tion. Record the identified difference.
X.
13 Get your recorded reading checked by your instructor.

TASK 7 : Identify and quick test given DIAC

1 Record the type code number of the given DIAC. 2 From the measured resistance in both directions of the
Measure & record the resistance of the DIAC in both the DIAC record your conclusion about the condition of the
directions in Table 3. DIAC.
Refer lesson 1.3.14 for assistance to give conclusion.
3 Get your work checked by your instructor.

146 IT & ITES : ICTSM - Exercise 1.3.14

TASK 8 : Find the break-over voltage of the DIAC

1 Wire a simple Diac test circuit as shown in Fig 3. Get 3 Measure & record the initial voltage across TP1 and
it checked by your instructor. across the DIAC in Table 4.
4 Observing the voltage across the TP1 and across the
Do not connect the variac to AC mains.
DIAC, slide the variac knob such that the output of
variac increases till the point(VBO) at which, the increas-
ing voltage drop across the Diac suddenly drops to a
very low value. Record the voltage across TP1 and
across the DIAC(VBO).
5 Switch-off AC mains supply. Repeat steps 2 to 4 to
confirm break-over voltage of the DIAC under test.
6 Get your work checked by your instructor.

2 Keep the Variac in minimum output voltage position.

Connect the primary of the isolation transformer. Switch-
on mains AC supply to the primary of the isolation
transformer.

IT & ITES : ICTSM - Exercise 1.3.14 147

 Record sheet for Exercise 1.3.14

1 Table 1

Label No. Code No. Measured resistance between Conclusion

A&K G&K G&A
Forward Reverse Forward Reverse Forward Reverse

2
a) Resistance between anode and cathode before shorting the anode with gate ______________.
b) Resistance between anode and cathode with anode to gate shorted ______________.
c) Resistance between anode and cathode after removing the short between anode and cathode ______________.
d) Condition of SCR after testing with jig ______________.

3 Specifications of the chosen triac

a) IT ______________.
b) VGT ______________.
c) VDRM ______________.

4
Triac Resistance Conclusion
No. MT2 & MT1 MT2 & Gate MT1 & Gate
Forward Reverse Forward Reverse Forward Reverse

5 Table 2

Type number of TRIAC:

Gate Trigger VGT IGT

mode volts mA

Mode I
MT2(+) VG(+)

Mode II
MT2(+) VG(-)

Mode III
MT2(-) VG(-)

Mode II
MT2(-) VG(+)

148 IT & ITES : ICTSM - Exercise 1.3.14

6 Table 3

Code Number of Diac Resistance in one Resistance in other

direction direction
(between two terminals of
DIAC)

7 Table 4

Sl.No. VTP1 Vdiac

(VBO)

IT & ITES : ICTSM - Exercise 1.3.14 149

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.15

Construct and test Crow bar protection circuits using SCR(s)

Objectives: At the end of this exercise you shall be able to
• construct a crow bar protection circuit for a 5V DC supply
• construct a crow bar protection circuit for AC mains supply.

Requirements

Tools/Equipments/Instruments 4K7,¼W - 1 No.

1K,¼W - 1 No.
• Trainees kit - 1 No.
220 Ohms,¼W - 1 No.
• Variable DC PSU 0-10V,1A - 1 No.
• General purpose PCB - 1 No.
Materials/Components • Two point terminal strips for mains - 2 Nos.
• Flexible wire,5A,240V - 2 mts each
• General purpose PCB - 1 No.
(Red and Black)
• Semiconductors
• Semiconductors
SCR of 50 volts rating - 1 No.
SCRs of 400 volts rating - 2 Nos.
Transistor 2N 3702 or equivalent - 1 No.
Diodes, 1N4007 - 4 Nos.
Zener, 4V7, 400mW - 1 No.
Zener, 120V/1W - 1 No.
LED, Red colour 5mm - 1 No.
• Resistors 22K, 3W - 1 No.
LED, Green colour 5mm - 1 No.
(or 2 Nos. of 47K, 2W in parallel)
• Resistors
• 240V, 3Watts lamp - 1 No.
100 Ohms, 2W - 1 No.

For satisfactory performance of circuit given in Fig 2, it is advised to use SCRs whose gate current(min)
is 6mA.

PROCEDURE

TASK 1: Wire and test a 5 Volts DC crow-bar circuit using an SCR

1 Clean the general PCB strip on which the crow bar 4 Vary the input voltage from 4 volts to 8 volts in steps of
circuit is to be wired. Test the components to be wired. 0.5 volts. At each step record the input and load
voltages and status of the LEDs.
2 Wire the DC 5 volts crow bar circuit on the cleaned
general purpose PCB strip referring to the circuit 5 Decrease the input voltage to 4 volts in steps of 1 volt
schematic shown in Fig 1. Get the wired circuit checked and at each step record the input and output voltage and
by your instructor. status of LEDs.
6 Temporarily disconnect DC supply connected to the
crow bar circuit and reconnect it again. Measure and
record the input, and load voltage and status of LEDs.
This temporary disconnection is required to turn off the
SCR.
7 Vary the input DC supply to the crow bar circuit
gradually and identify & record the input voltage at
which the load voltage becomes almost zero. (Red LED
glows and green LED turns off)
8 Decrease input voltage to 4 volts. Repeat steps 6 and
7 a few more times to confirm the input voltage at which
the load voltage becomes zero.
9 Get your work checked by your instructor.
3 Connect a variable DC supply (0 to 10V) for giving DC
input to the wired circuit.

150
TASK 2: Wire and test a over voltage protection circuit for mains AC supply.

1 Wire the circuit shown in Fig 2 on a general purpose tag/ 3 Keep AC mains ON/OFF switch to OFF. Connect the
lug board. Without connecting the mains supply and output of variac to the wired circuit input and AC mains
the load, get the wired circuit checked by your instructor. to input of variac.

Since 240 V mains supply will be on the wired 4 Set the output control knob on variac to 200 Volts
circuit, use insulated multistrand wire for circuit without switching on the mains AC.
interconnections. Make sure there is sufficient 5 Switch-ON mains. Measure and record the input
(5 cms) gap between the soldered live and voltage,output voltage and status of lamp load.
neutral wires coming from mains and going to
the load. For safe working you are advised to 6 Increase the AC input to the wired circuit in steps of 5
mount the wired strip inside a wooden junction volts up to 250 volts observing the output voltage and
box with input and output wire pairs coming status of the lamp load. At each step record the input
out of the box through two point terminal strips. & output voltages and the status of the lamp load.
Once the input rises above 240 Volts the output voltage is
2 Connect a lamp load to the wired circuit. expected to become zero and hence the lamp will turn off.
You may use the mains lamp tester itself as a load. If this does not happen even at 250 volts input, consult your
instructor.
7 Switch- OFF mains supply. Repeat steps 4 and 5.
8 Increase gradually the AC input voltage to the wired
circuit till such point at which the load lamp just turns-
OFF and record the input voltage.
9 Repeat steps 7 and 8 a few more times to identify a
more closer input voltage at which the output voltage
becomes zero.
10 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.3.15 151

 Record sheet for Exercise 1.3.15

TASK 1 TASK 2

1 Instructors remarks on the neatness and correctness 1 Instructors remarks on the neatness and correctness
of the circuit wired. of the circuit wired.

Very good Good Satisfactory Poor Very good Good Satisfactory Poor

2 2

DC DC Status of LEDs Input Output Status of lamp

input output Red Green voltage, AC voltage, AC load (ON/OFF)
voltage voltage (ON/OFF) (ON/OFF)
200
4.0V
205
4.5V
210
5.0V
215
5.5V
220
6.0V
225
6.5V
230
8.0V
235
7.5V
240
8.0V
245
7.0V
250
6.0V

5.0V
3 AC input voltage at which output
4.0V voltage become zero : volts
(lamp load turns-OFF)

Input voltage at which output

voltage becomes zero : volts
(RED-ON, GREEN-OFF)

(Trainee) (Instructor)

152 IT & ITES : ICTSM - Exercise 1.3.15

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.16

Construct and test a Lamp dimmer/fan motor speed regulator using TRIAC
and DIAC
Objectives: At the end of this exercise you shall be able to
• assemble and test a lamp dimmer cum fan speed regulator using TRIAC and DIAC
• test the circuit using lamp and domestic fan.

Requirements

Tools/Equipments/Instruments • Neon indicating lamp 240V - 1 No.

(Jeweled type)
• Trainees tool kit
• Gang box, 150 x 100 mm - 1 No.
• Lamp load (60 watts 230V) - 1 No.
(used for open conduit wiring)
• Table Fan, 80 watts - 1 No.
• Hylum board 150 x 100 mm - 1 No.
Materials/Components • Self tapping screws 3mm x 10mm - 6 Nos.
(for fixing hylum board on gang box)
• Printed circuit Board, Code. No:5 - 1 No.
• 5 amps, 240V flush type socket - 1 No.
(Refer appendix for PCB
• SPST switch flush type, 5 amps, 240V - 1 No.
design drawing)
• Terminal strip (3 point) - 1 No.
• Resistors 180 ohms 1w ±5% - 1 No.
• Spacers 3mm x 10mm - 4 Nos.
4K7 1/4w 5% - 1 No.
(To separate PCB from gang box)
470 K Ohms 1/4w 5% - 1 No.
• Knob (for potentiometer) - 1 No.
• Potentiometer
• 3 core mains cord, 240V, 5 amps - 1 No.
250K, 16 mm plastic shaft - 1 No.
• Soldering lead and Flux - as reqd.
• Capacitor 0.1 μFD 400 volts - 3 Nos.
• Fuse 500 mA - 1 No.
• Traic BT136 or equivalent - 1 No.
• Diac D3202 or equivalent - 1 No.
• Inductor - 1 No.
(25 SWG,40 turns on 10mm ferrite rod
with former made of leatheroid paper)

PROCEDURE

1 Clean the PCB. Check the circuit components and 2 Assemble the Lamp dimmer/Fan controller circuit refer-
confirm their working condition. ring to the circuit schematic diagram shown in Fig 1 &
PCB layout diagram shown in Fig 2.
3 Get the wired circuit checked by your instructor.

153
4 Mount the POT, POT Knob, SPST mains switch, 3 pin Light intensity may be recorded as very dim, off or such.
mains socket and the neon lamp on the 150X100 mm
13 Increase the intensity of lamp gradually by turning the
hylam board. Get it checked by your instructor.
POT from minimum position to maximum position.
5 Fix the 3 point terminal strip inside the wooden gang Check and record the light intensity at other extreme
box near the hole through which the mains cord is to be position of the POT.
laid.
Light intensity may be recorded as bright, very bright or
6 Prepare a power cord with one end terminated to a 3-pin such.
mains plug and the other end is skinned and tinned.
14 Repeat steps 12 and 13 a few more times to confirm that
7 Take the power cord through the side hole of the wooden the wired lamp dimmer circuit is working satisfactorily.
gang box. Solder one end of the mains power cord at the Get it checked by your instructor.
terminals of the terminal strip.
15 Switch-off AC mains supply to the circuit and remove
8 Keeping the PCB close to the gang-box, solder wires the plug connection from mains supply.
between,
16 Fix the PCB to the gang box. Get it checked by your
– mains to switch and fuse mounted on the gang box instructor.
– fuse to Neon lamp 17 Fix the hylam board mounted with switch, socket,
potentiometer and neon indicating lamp, to the gang
– fuse to PCB, at points marked on PCB
box.
– PCB/mains(ground line) to 3-pin socket
18 Repeat steps 10 to 14 to confirm satisfactory working
– PCB to POT of the circuit after fixing it in the gang box.
Use multistrand flexible insulated wire for these connections 19 Remove the lamp load connected at the controlled
as these wires will carry a.c mains voltage and large current output of the lamp dimmer circuit. Connect a table fan
of the order of a few hundred milli ampers. to the controlled AC output of the wired circuit.
9 Keep the PCB on any insulated material. Keep the POT 20 Swich-on AC mains supply to the circuit. Vary the POT
in mid position. Put A.C mains SPST switch mounted from one end to the other, observe and record the speed
on the gang box to OFF. of the fan at min, middle and max position of the POT.
10 Connect a test lamp at the mains output socket(mounted You may use a non-contact type tachometer to record
on the gang box). speed of fan.
11 Connect a.c mains supply to the wired circuit. Put the 21 Get your work checked by your instructor.
SPST switch mounted on the gang box to ON. Check
22 Write your name on a piece of paper and paste it on the
if the lamp glows.
gang box.
If the lamp is not glowing, switch off mains supply and
consult your instructor. The Lamp dimmer cum Fan speed controller is
a very versatile and a very useful gadget. You
12 Vary POT position such that, the light intensity of the
can make use of this project constructed for
output lamp gradually decreases and becomes mini-
any useful purpose.
mum/zero. Record the status of the lamp intensity at
one extreme position of the POT.

Record sheet for Exercise 1.3.16

1 Neatness and correctness of the wired circuit on PCB 3 Status of the lamp intensity when the pot VR1 is at other
extreme position _____________________.
Very Good Good Satisfactory Poor
4 Instructors remarks on the performance of the circuit

2 Status of the lamp intensity when the pot VR1 is at one

extreme position _____________________.

154 IT & ITES : ICTSM - Exercise 1.3.16

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.17

Construct and test series voltage regulator circuit

Objectives: At the end of this exercise you shall be able to
• construct a given simple series regulator circuit
• measure output voltage and current
• measure the ripple at input and output of the regulator and find ripple factor RR
• construct a series regulator with voltage-feedback
• test the regulator and find its percentage regulation and ripple rejection.

Requirements

Tools/Equipments/Instruments 220 Ω - 1 No.

330 Ω - 1 No.
• Trainees kit
• Capacitor, 10μF, 25 V - 1 No.
• Unregulated dc power supply,
• LED, Red colour - 1 No.
17VDC - 1 No.
• Hook up wires (Red and Black) each - 3 Mts.
• CRO, 20 MHz - 1 No./batch.
• Rosin core solder - 30 gms.
Materials/Components • Series regulator wired in Task-1 - 1 No.
• Transistor, BC147 or equivalent - 1 No.
• Tag board - 1 No.
• Zener diode, 9.1V, 1/4W - 1 No.
• Transistor SL100 or equivalent - 1 No.
• Resistors
• Zener diode, 12V, 1/4W - 1 No.
1.5 kΩ, 1/4 W - 1 No.
• Resistors, carbon, 1/4W, 10%
3.3 kΩ, 1/4 W - 1 No.
180 Ω - 1 No.
820 Ω, 1/4 W - 1 No.
1K Ω - 1 No.
330 Ω, 1/4 W - 1 No.

PROCEDURE

TASK 1: Construct and test a simple series regular circuit

1 Refer data book and record the required details of the 4 Connect an unregulated dc voltage of 17V to the input
given transistor(SL 100 or equivalent) in Table 1 of terminals of the wired series regulator board.
record Sheet.
5 Get the interconnections made checked by your
2 Test to confirm good working condition of the given instructor.
transistor and other circuit components.
6 Switch-on the ac mains supply to the unregulated dc
3 Solder the components on the given Tag board as per supply.
the schematic diagram and layout shown in Fig 1 and
7 Measure and record the input voltage and output voltage
2 respectively. Get the wired circuit checked by your
of the series regulator.
instructor.
8 Measure and record the following voltage levels in
Note that the tag board is already wired with bridge
record Sheet.
rectifier with filter in earlier exercises.
a) Voltage across zener, VZ
Fig 1
SL100 OR EQUV + b) VCE of the transistor Q1
C E
RED
c) VBE of the transistor Q1.
Q1
LED
9 Using a CRO, measure and record the peak - peak
330Ω

R SZ
B ripple voltage at the input and output of the regulator.
REGULATED DC, 12V
UNREGULATED

10 μ F/25V
10 Switch off mains supply. Replace the 220 Ω load
15V - 18V

220 Ω

C RL
DC

resistor RL by a 180 Ω resistor.

R SL
1KΩ

Z 12V VZ

--

155
 With RL = 180W, the load current will increase from the
Ω, this
Do not use RL of value lower than 180Ω
earlier 55mA to 66mA. This results in a total load of
will load the regulator beyond is designed
10.3mA through LED, plus, 66mA through RL (10.3mA
load current which will damage the pass
+ 66mA = 76.3mA). By doing this, you are still in safe
transistor.
loading the regulator because the regulator was de-
signed for a load of <100mA. (Refer lesson 1.3.17 step 11 With increased load current, repeat steps 7, 8 and 9.
3, note)
12 Get your work and recorded readings checked by your
instructor.

Fig 2 12
1 5 9 22 28 34 41 47 51 55

1 13 14 RED
B 15 SL 100 LED
Q1 29 48
330 Ω

RSZ 23
30 31 35
RSL 1KΩ 52
+

REGULATED DC,12V
16 42
+
UNREGULATED

10 32
2 17 56
15 TO 18V

36 43

10μ F/25V
25

220Ω
6 18 19 37 RL
49
7 38 44
3 53 57
-- 20
39 45
26 --
VZ

Z 12V

4 8 11 21 27 33 40 46 50 54 58

TAG BOARD CODE NO: 111 - 01 - TB

TASK 2: Construct and test series regular with voltage feedback

1 Collect the components required to carry out task 2. 4 Get the modified circuit checked by your instructor.
Test to confirm good working condition of the compo-
5 Connect the output of unregulated dc power supply to
nents. Identify and put sleeves to the transistor leads.
the input of the wired regulator circuit board.
2 Test the ouput of the unregulated power supply to
6 Measure and record the unregulated DC input voltage,
confirm its good working condition.
and the regulated dc output voltage.
The expected unregulated power supply output voltage
7 Using a CRO, measure and record the peak-to-peak
is 17 to 18V.
ripple voltage at the input and the output of the wired
3 Referring to the schematic and layout diagram of the regulator.
series regulator with voltage-feedback shown in Fig 3
8 Measure and record the following voltage levels in
and Fig 4 respectively, modify the wired simple series
record sheet.
regulator circuit wired in task 1.
i) VZ
Fig 3 -I
-E
-I
-L ii) VF
C SL100 OR EQUV
+
-I
-d
-I
- LED
iii) VCQ1
RED
Q1 LED
RB 3K3 iv) VCEQ2
330Ω
820Ω

RZ R1
9 Switch-off mains supply. Connect a 180Ω resistor in
REGULATED DC, 12V
UNREGULATED

B
place of the existing 220Ω load resistor RL.
DC, 18VOLTS

10μ F/25V
220Ω

BC147 C RL
This reduced RL increases the load current to 67mA.
Hence the total current through the pass transistor will
1KΩ

R SL
Z 9.1V R2 1K5 be a 6.5mA of Id + 10.3mA of ILED + 67mA of IL.

Do not use a resistor of less than 180W as RL.

--
10 With increased load (RL = 180Ω), repeat steps 6, 7
and 8.

156
11 From the recorded readings in record sheet, calculate To get Vout(No load), temporarily open RL and measure.
and record, Measure Vout(full load) with RL as 180Ω.
i) Percentage load regulation 12 Get your work checked by your instructor.
ii) Ripple rejection ratio

Fig 4 12
5 Q1 22 28 34 41 55
1 9 47 51

1 13 14 RED
B 15 SL 100 LED
R1 330Ω 48
RB 29
3K3
820 Ω

RZ 23
30 31 35
RSL 1KΩ 52
+

REGULATED DC,12V
UNREGULATED DC

16 42
+ 10 32
2 17 56
18VOLTS

10μ F/25V
Q2 25 36 43

220 Ω
6 18 37 RL
19 49
7 BC 147 38 44
3 53 57
-- 20
39 45
26 --

R2
1K5
Z 9.1V

4 8 11 21 27 33 40 46 50 54 58

TAG BOARD CODE NO: 111 - 01 - TB

IT & ITES : ICTSM - Exercise 1.3.17 157

 Record sheet for Exercise 1.3.17

1 Table 1: Specification of the transistor used

Pin VCE IC Max. device bdc Application

layout Max Max dissipation

2 Neatness of wired circuit Very good Good Satisfactory Poor/Redo

3
Condition Unregulated Vz VBE VCE Regulated Input Output
dc input dc output ripple level ripple level

Load
Ω
RL = 1.2KΩ

Load
Ω
RL = 820Ω

TASK 2
1 Remarks on correctness and neatness of wired circuit: Very good Good Satisfactory Poor/Redo

2
Condition Unregulated Regulated Input ripple Output ripple V V V V
Z F CQ1 CEQ2
dc input dc output (peak-to-peak) (peak-to-peak)

With
R = 1KΩΩ
L
With
R = 820ΩΩ
L

3 Percentage load regulation : _________________

4 Ripple rejection ratio : _________________

(Trainee) (Instructor)

158 IT & ITES : ICTSM - Exercise 1.3.17

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.18

Construct and test fixed and variable regulated power supply using ICs
Objectives: At the end of this exercise you shall be able to
• construct and test a +12 volts regulator using a 7812 three-pin regulator
• modify a fixed +12 V regulator to get a higher output voltage using a zener diode
• modify a fixed +12 V regulator to get a variable output regulator
• construct and test a 1.2V to 3V variable output regulated power supply.

Requirements

Tools/Equipments/Instruments • Capacitor 270nf, disc - 1 No.

• 10μf, 25 V, electrolytic - 1 No.
• Trainees kit
• Preset/Potentiometer, 470W - 1 No.
• Rheostat 100Ω, 50W - 1 No./batch.
• Red LED - 1 No.
• CRO, 20MHz - 1 No./batch.
• Resistor 820Ω, 1/4 W and 1KΩ, 1/4W - 1 each.
• DC ammeter, 0-1A - 1 No./batch.
• Hook up wires (red and black colour) - 1 Mtr.
• 12V power supply - 1 No.
• Rosin cored solder -10 cms
Materials/Components • Wire sleeve (R,Y,G) each - 2 cm
• 1N 4002 or By127 diode - 1 No.
Component list for Tag board power supply
• Resistors
• Tag board Code No. - 1 No.
4.7K potentionmeter carbon rotary - 1 No.
• Three-pin voltage regulator
2.2K carbon, 1/2W - 1 No.
μA7812 or equivalent - 1 No.
220Ω, carbon, 1/4 W - 1 No.
• Heat sink for 7812 - 1 No.
3 terminal voltage regulator
(use suitable heat sink )
LM317T TO-20 - 1 No.
• Zener diode 6.1 V, 1/4 W - 1 No.

PROCEDURE

TASK 1: Construct and test a +12 V fixed voltage regulator

1 From the type code marked on the given 3 pin regulator

Fig 1
IC, identify and record the IC’s specifications in record + IN 7812 OUT
+
1 3
sheet. COM RED
2 LED
UNREGULATED
DC VOLTAGE

DC VOLTAGE
REGULATED
2 Identify the terminals of 7812 and put sleeves to the 270nF +
16V-20V

C1 C2 10μ F

12V
terminals using colour coding scheme given below; -- 25V
820Ω

R1
Input - Yellow/Orange sleeve.
Common - Green/Black sleeve. -- --
Output - Red sleeve. +12V FIXED OUTPUT VOLTAGE REGULATOR CIRCUIT

SPEC: OUTPUT DC:12V, RATED MAX LOAD 800mA

3 Get the work done in steps 1 and 2 checked by your
instructor.
The unregulated dc voltage to the regulator
4 Fix the heat sink on IC 7812 as demonstrated by your should not be more than 24 volts; otherwise the
instructor. Refer Fig 2 for the position of heat sink on the IC may get damaged.
tag board.
5 Construct the voltage regulator circuit referring to the The unregulated dc voltage to the regulator should be
schematic and layout diagram shown in Fig 1 and Fig atleast 15 volts, otherwise the regulator may not work
2. satisfactorily.

6 Get the neatness and correctness of your wiring checked 8 Using loading rheostat, load the regulator in steps of
by your instructor. 200 mA upto 800mA and at each step measure and
record,
7 Apply 16 to 20 volts unregulated dc voltage to the input
of the wired 12V regulator. Record the unregulated input – Regulated dc output voltage
voltage and no-load output voltage of the regulator in – Input and output ripple.
record sheet.
159
 Loading is limited to 80% of its rated maximum Fig 2
of 1A. This is because the heat sink used with 7812

7812 may not be very effective in taking away 1 2 3

the heat.
IN OUT
COM
9 From the recorded readings, calculate the + 3 5 9 14 15 19 23
+ 26
1
– output voltage regulation at each step of loading. 20
RED
LED
16
– ripple rejection at each step of loading.

DC VOLTAGE 12V
UNREGULATED
DC VOLTAGE
6 10 24

REGULATED
16 TO 20V

10μ F/25V

OUTPUT
INPUT
C1 11
10 Get your work checked by your instructor. 17
C2

820Ω
270nF
7 12 R1

21
4 18
8 13 22
2 25
-- --
27
43

CODE NO: 111 - 05 - TB

TASK 2: Construct a +18V output voltage using +12 fixed voltage IC regulator (IC7812)

1 Test and confirm the condition and voltage rating of the 5 Repeat steps 8,9 and 10 of Task 1 to measure the
zener diode. output regulation and ripple rejection.
2 Modify the wired +12V fixed output voltage regula- 6 Get your work checked by your instructor.
tor circuit in Task-1 to that shown in Fig 3 & Fig 4.
3 Get the neatness and correctness of the wiring checked Fig 3
by your instructor. + IN 7812 OUT
+
1 COM 3
RED
4 Apply unregulated dc voltage in the range of 16V-20V to 2 R1 1K8 LED
UNREGULATED
DC VOLTAGE

DC VOLTAGE
REGULATED
the regulator. Record the no-load output voltage of the C1
270nF C2 10μ F
20V

18V
regulator in the record sheet. 25V

1K Ω
R1
Use o/p of any DC PSU to give input of 20V. Z 6.1V

-- --
+18V FIXED OUTPUT VOLTAGE REGULATOR CIRCUIT
SPEC: OUTPUT DC:18V, RATED MAX LOAD 800mA

Fig 4

7812

1 2 3

IN OUT
COM
3 5 9 14 19 23 26
15
+ 1 +
RED
R1 1K8 20 LED
10 16
UNREGULATED
DC VOLTAGE

DC VOLTAGE

6 24
REGULATED
10 μ F/25V

270nF
C1
20V

18V

11 C2
Z
1K Ω

7 6.1V 17 R1
12
21
4
8 13 18 22 25
-- 2 27 --
43

CODE NO: 111 - 05 - TB

160 IT & ITES : ICTSM - Exercise 1.3.18

TASK 3: Construct and test a Variable output voltage regulator using +12V fixed voltage regulator (IC7812)

1 Test to confirm the condition of the potentiometer or pre- Fig 5

set. IN 7812 OUT
+ +
2 Modify the wired +18V fixed output voltage regulator in COM RED
1K LED
Task 2 to that shown in Fig 5.

UNREGULATED
DC VOLTAGE

DC VOLTAGE
REGULATED
270nF C2 10 μ F

12V-18V
C1
.3 Apply unregulated dc voltage of 20V to the regulator.

20V
25V
Record applied input voltage. R1 1K
470Ω
4 Measure and record the no-load output voltages of the -- --
regulator at the two extreme positions of the pot/pre- VARIABLE OUTPUT VOLTAGE REGULATOR CIRCUIT
set.
5 With the pot/pre-set adjusted such that the output 6 Get your work checked by your instructor.
voltage is the maximum, repeat steps 8,9 and 10 of
Task 1 to measure and record the output regulation and
ripple rejection.

TASK 4 : Construct and test 1.2V to 30V variable output regulated power supply

1 Test all the components to confirm their good working 4 Construct a variable regulated output power supply on
condition. Record the specifications of IC LM317T in the given general purpose PCB, referring to the circuit
record sheet. schematic shown in Fig 6.
2 Check the given general purpose PCB for the following Assemble all components on GEN-PCB including the
defects and correct them or take a new board; fuse holder, except the step-down transformer. Use
suitable heatsink to IC 317 T.
• Broken tracks • Joined tracks • Closed holes
5 Get the correctness and neatness of wiring checked by
3 Clean the copper side of the PCB using alcohol or other
your instructor.
cleaning agents. Wash, wipe and dry the PCB.

6 Connect the secondary of (230:24V) transformer to the 7 Measure and record the unregulated dc input and the
wired circuit. Switch-on mains supply. minimum, maximum variable voltage of the regulator
under no-load condition.
Switch OFF main supply immediately if burn-
ing, smoking overheating, sparks are observed 8 Set the output to +15 volts and load the output using a
in any of the components, and report to your loading rheostat in steps of 200 mA up to 600 mA. In
instructor. Check the IC and ensure that it is each step measure and record the output voltage and
not heated-up the ripple voltages.

IT & ITES : ICTSM - Exercise 1.3.18 161

 10 Using a dc current meter (0-1A range) short the load
Load current is restricted to 600mA as the heat-
terminals momentarily and record the short circuit fold
sink is provided to the IC may not be the ideal
back protection current level.
one.
11 Get the readings checked by your instructor.
9 Calculate and record the output regulation and ripple
rejection of the regulator.

Mount the regulator IC on a good heat-sink (available in market). If a good heat-sink is used with the IC,
you can draw upto 1Amps easily. Mount the transformer and the wired PCB in a metallic box of suitable
size. Mount the POT on the front panel of the cabinet box. Mount output terminal sockets (Red and black)
on the front panel of the box from which variable DC voltage can be taken. This will serve you as a 1.2V
to 30V, 1A rating variable regulated DC power supply for servicing circuits in forthcoming exercises as
well for your hobby gadgets and general servicing.

Record sheet for Exercise 1.3.18

TASK 1: +12V fixed voltage regulator using 7812

1 IC specifications from marked code
Type code Manufacturer Type of Output Rated max. Package type
regulator voltage load current
Positive/Negative

2 Neatness and correctness of wiring: Very good Good Satisfactory Poor/Redo Continue Exercise

3 Level of unregulated input voltage to the regulator : ____________

Load - Current

No-load 200 mA 400 600 800

Output voltage

Input ripple (P-P)

Output ripple

Ripple rejection

Output regulation

162 IT & ITES : ICTSM - Exercise 1.3.18

TASK 2 : +18V fixed voltage regulator using 7812 and 6 V zener
Neatness and correctness of wiring: Very good Good Satisfactory Poor/Redo Continue Exercise

2 Level of unregulated input voltage to the regulator : ____________

Load - Current

No-load 200 mA 400 600 800

Output voltage

Input ripple (P-P)

Output ripple

Ripple rejection

Output regulation

TASK 3 : Variable output voltage regulator +12 to +18 volts using 7812
1 Level of the unregulated input voltage to the variable output regulator : ____________

Load - Current

No-load 200 mA 400 600 800

Output voltage

Input ripple (P-P)

Output ripple

Ripple rejection

Output regulation

2 No-load output voltage levels: (i) Minimum adjustable: (ii) Maximum adjustable :

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.3.18 163

TASK 4 : Variable regulator using LM317

1 Specification of the given 3-terminal regulator IC.

Type Package Output voltage Max. output
number type Min. Max. current

2 Neatness and correctness of wiring: Very good Good Satisfactory Poor/Redo

3
Unregulated dc input to regulator : ____________________
Minimum adjustable output voltage (No-load) : ____________________
Maximum adjustable output voltage (No-load) : ____________________

4
Set output voltage : 15 volts

Load current 200mA 300mA 400mA 500mA 600mA

Output voltage

Output ripple (p-p)

Input ripple

Output regulation

5 Shorted output current I :

SC

6 Specification of the given 3-terminal regulator IC.

Type Package Output voltage Max. output

number type Min. Max. current

7 Neatness and correctness of wiring: Very good Good Satisfactory Poor/Redo

8
Unregulated dc input to regulator : ____________________
Minimum adjustable output voltage (No-load) : ____________________
Maximum adjustable output voltage (No-load) : ____________________

164 IT & ITES : ICTSM - Exercise 1.3.18

9 Set output voltage : 15 volts

Load current 200mA 300mA 400mA 500mA 600mA

Output voltage

Output ripple (p-p)

Input ripple

Output regulation

10 Shorted output current I :

SC

IT & ITES : ICTSM - Exercise 1.3.18 165

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.19

Identify the controls of an UPS and operate

Objectives: At the end of this exercise you shall be able to
• identify the various terminals, switches, indicators, controls and settings
• operate an UPS.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees tool kit • Patch cords - as reqd.
• UPS 1 KVA - 1 No./batch.
• Voltmeter 0-300V/AC - 1 No./batch.
• Variac 0-300V/1A - 1 No./batch.

The instructor shall demonstrate the use of various switches, indicators and other accessories. He shall
demonstrate the procedures of operating the UPS and maintaining the batteries.

PROCEDURE

TASK 1: Identification of various switches, indicators and input output terminal

1 Draw the front panel of the UPS with indicators and 3 Referring to the manual record the positions of the AC
switches in the Record sheet. input, output and other fuses/ MCBs (miniature circuit
2 Referring to the manual record a brief function of the breaker).
switches and the indicators in Table 1. 4 Get your work checked by the instructor.

TASK 2: Operate an UPS

1 Record the specification of the given UPS from the label 6 Switch the direct supply / UPS supply switch to UPS
attached to the UPS or from the manual in the Record supply mode.
sheet.
7 Record the input, output and the battery voltages along
2 Connect the UPS to mains supply. with any other LED indication(status) in the record
3 Switch ON the mains MCB(switch). sheet.

Observe the battery voltage indicator the meter should 8 Get your work checked by the instructor.
indicate the full rated voltage of the battery do not operate 9 Switch OFF the AC supply to the UPS input, record
the UPS when the low battery indication or the beep are the input, output and the battery voltages along with
ON any other LED indication(status) in the record sheet.
4 Switch on the DC MCB. 10 Get your work checked by the instructor.
Observe out put voltage indicator for the building up of the 11 Switch off any gadgets (load)connected to the UPS.
AC voltage to 240V
Do not press reset switch of the UPS with output loaded.
5 Switch on the AC output MCB.
12 Switch off the AC output of the UPS.

166
 Record sheet for Exercise 1.3.19

1 Space for drawing front panel of UPS

2 Table 1

Name of switch/ Symbol if any Brief function Remarks

socket etc. LED indication

3 Specification of the UPS

4 Voltage in supply mode (Direct supply)

a) Battery voltage -
b) Input voltage -
c) Output voltage -

5 Voltage in UPS mode (AC OFF condition)

a) Battery voltage -
b) Input voltage -
c) Output voltage -

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.3.19 167

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.20

Demonstration of the internal parts of a CRO

Objectives: At the end of this exercise you shall be able to
• locate the internal parts of a CRO
• locate exterior parts of a CRT of a single trace and dual trace
• identify various sections of a CRO
• adopt the method used for mounting/fixing of various parts of a CRO.

Requirements

Tools/Equipments/Instruments
• Oscilloscope, Single beam,
Single trace - 1 No.
• Oscilloscope, Dual trace,
30Mhz or above - 1 No.

In this exercise the instructor will open the cabinet/outer cover of two or three different types of CRO
and show the internal parts of the CRO. During the demonstration observe and record the important
parts and infromations of CRO. Also record the difference in the internal parts and mounting technique
observed in different types of CRO’s shown by the instructor.

168
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.21

Measurements using oscilloscope

Objectives: At the end of this exercise you shall be able to
• calibrate the given CRO using internal calibration signal
• measure frequency and phase of a signal using lissajous waveform method
• measure the propagation delay in digital signals using a divide-eight-counter.

Requirements

Tools/Equipments/Instruments • Signal generator - 1 No./batch.

• Trainees tool kit - 1 Set. • Operating manual of CRO - 1 No./batch.
• Cathode ray oscilloscope Materials/Components
20 Mhz, Dual trace - 1 No./batch.
• Cathode ray oscilloscoe • Patch cords - as reqd.
100 Mhz - 1 No./batch of 8

Guide lines for carrying out the tasks:

The procedure for carrying out each task given under objectives will be demonstrated by your instructor
using the procedual steps finalized in the related theory class room session. During the demonstration,
the trainees are expected to observe and record the important points other than the general CRO usage
procedure already known to them. You may also take the help of your instructor whenever required.

PROCEDURE

1 Take up individual task for test/measurement.

Do not hesitate to repeat the test if you are not
2 As per the test setup finalized for the task (prepared in convinced with the test results.
the class room session), connect the test setup and get
it checked by the instructor. 4 Get the test results checked by your instructor.
3 Follow the procedural steps finalized for the task 5 Repeat steps 1 to 4 for the remaining tasks of this
(prepared in the classroom) and carryout test/measure- exercise
ment for the task taken-up. Record test results in the
tabulaton sheet prepared by you in the class for this
task.

169
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.22

Use of controls in dual trace, dual beam and storage oscilloscope

Objectives: At the end of this exercise you shall be able to
• use X5 and X10 magnification of in the critical deflection factor control
• use different coupling modes of the vertical input
• use CH1 and CH2 inputs of a dual trace oscilloscope effectively
• use alternate and choped modes for two inputs
• use different triggring modes such as INT, EXT, EXT/5 or EXT/10
• use different trigger source coupling modes such as LF reject, HF reject
• use different sweep display modes
• use X-Y mode of operation
• use Z-axis input
• use beam1 and beam2 in a dual beam oscilloscope
• store a wave form on a storage oscilloscope
• erase and restore images on the storage oscilloscope.

Requirements

Tools/Equipments/Instruments • Oscilloscope, storage type - 1 No.

• Manuals of the oscilloscope used - 1 No. of each • Signal generator - 1 No.
type/batch. Materials/Components
• Oscilloscope, Dual trace,
20MHz or above - 1 No. • Patch cords - as reqd.
• Oscilloscope, Dual beam,
20MHz or above - 1 No.

In this exercise, the instructor will demonstrate the use of various features of dual trace, dual beam and
storage oscilloscope using relavent inputs required for demonstration. During the demonstration observe
and record the controls used by the instructor and procedure for using them depending upon the type of
input signal used. Refer oscilloscope user manual for clarity as and when required.

170
IT & ITES
ICTSM - Basic Electronics Exercise 1.3.23

Construct and test amplitude modulator/AM transmitter

Objectives: At the end of this exercise you shall be able to
• construct and test an amplitude modulator
• use the modulator to transmit AM signals
• receive the transmitted AM signals using a AM receiver.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainee’s kit • Refer Fig 1 for component list.
• DC power supply: 12V,100mA - 1 No. • AM transmitter tag board - 1 No.
• Oscilloscope, 20 MHz - 1 No./batch. • Solder and soldering paste - as reqd.
• Pocket transistor radio - 1 No./batch. • Hook-up wires - as reqd.
• Multi-strand wire(14/36) - 1 meter.

PROCEDURE

1 Refer the circuit diagram of a simple amplitude modulator 4 Power ON DC supply to the circuit and check for RF
and transmitter shown in Fig 1. Make the list of the signal(oscillator output) at the collector of Q .
2
components required to construct the AM modulator/
5 Tune the core of the oscillator coil to set the frequency
transmitter circuit. Get the list approved by your
of oscillations to around 650 KHz(1.5μSec). Measure
instructor. Collect the components and check the
and record the frequency and amplitude of RF oscillations.
components to confirm its good working condition.
6 Feed a 1KHz AF signal at the AF input and check for
Fig 1 presence of AF at the collector of Q .
2
7 Connect the link A-B disconnected at step 3.
+ 12V
8 Feed a signal of 1 KHz at the AF input of the modulator.
9 Observe the wave-form at the output of the modulator
2 using a CRO.
MW OCSILLATOR COIL

10K 220K
100K
0.1 μ F 10 Adjust the output level of the AF signal generator such
470PF
A that the modulated output is similar to that shown in Fig
1
10μ F
2.
BC148B BC148B
Q1 Q2 3 Fig 2
AF INPUT
B 10KPF
470K
POT 100 Ω
Vmax

Vmin

AF AMPLIFIER RF OSCILLATOR

AMPLITUDE MODULATOR
11 Referring to Fig 2, measure and record the levels of
2 Construct the circuit and get it checked by your V and V .
max min
instructor. 12 From the recorded reading of V and V calculate
max min
3 Temporarily disconnect the link A-B to test the AF and record the depth of modulation or modulation
amplifier and oscillator sections separately. index(m) and percentage of modulation m% using the
formula;
Link A-B disconnects the AF signal input to the modulator.

171
 Vmax – Vmin Fig 4
Depth of modulation, m = LENGTHY
Vmax + Vmin WIRE

Percentage of modulation,m% = m x 100.

The term m indicates the level to which the RF is modulated. 1KPF

The maximum value of m can be 1.

MW OCSILLATOR COIL
13 Get the modulated output wave form and your readings
checked by your instructor. 470PF

14 Increase the output level of the AF signal generator

slowly till the value of V = 0 as shown in Fig 3. BC148B
min Q2
This is the condition of 100% modulation or m=1.
100 Ω
Fig 3

18 Switch ON the transmitter. Place a Pocket radio(AM)

100% MODULATED CARRIER WAVE (m = 1)
close to the lengthy wire. Switch ON pocket radio and
tune it in medium waveband around 650 KHz.
15 Disconnect the signal generator and connect a crystal 19 Speak into the microphone and fine tune the pocket
or a dynamic microphone at the AF input terminals of radio to pick up the transmitted signal. Record the
the modulator. tuned receiver frequency. Check if the audio signal is
16 Speak into the microphone and observe the modulated clearly heard. Record your observation.
output wave-form. 20 Move the receiver away from the antenna wire and
17 Solder the one metre long wire at the collector of Q2 in check the maximum distance up to which the signals
series with a 1KPF capacitor as shown in Fig 4. can be picked up clearly. Record the approximate
distance.
With the simple wire acting as an antenna, the modulator
is now able to transmit the amplitude modulated signals Try orienting the antenna wire vertically or horizontally such
into free space, and hence, the circuit is now working as a that the distance covered is longer.
AM transmitter. 21 Get the working of the AM transmitter checked by your
instructor.

Record sheet for Exercise 1.3.23

1 Instructor's remarks on the correctness and neat- 3

ness of the wired AM transmitter Depth of modulation
Percentage
Vmax Vmin Vmax – Vmin of
Very good Good Satisfactory Poor m= modulation
Vmax + Vmin

2
(a) Measured frequency : ___________
of RF oscillations

4 Tuned frequency of radio receiver: ________KHz

(b) Measured amplitude of : ___________ 5 Maximum distance (aprox) at : ________
RF oscillations
which the radio can pick up
signals from the wired transmitter

(Trainee) (Instructor)

172 IT & ITES : ICTSM - Exercise 1.3.23

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.24

Construct & test a crystal AM receiver

Objectives: At the end of this exercise you shall be able to
• construct and test a crystal receiver
• improve the reception by adding a transistor amplifier.

Requirements

Tools/Equipments/Instruments • Resistors, carbon, 1/4W

• Trainees kit 220Ω - 1 No.
• Regulated DC power supply, 100KΩ - 1 No.
3V, 100mA - 1 No. 1 MΩ - 1 No.
• Regulated power supply, 12V, 500mA - 1 No. • Transistor
BC148B - 1 No.
Materials/Components • Crystal diode OA79 or equivalent - 1 No.
• Ferrite rod, 12 mm dia. 12 cm length - 1 No. • General purpose PCB (dot matrix) - 1 No.
• MW antenna coil - 1 No. • Mono headphone 32Ω or above - 1 No.
• Capacitors • Mono headphone socket - 1 No.
10 KPF - 2 Nos. • Hook-up wires - as reqd.
0.1 μF - 1 No. • Rosin-core solder - as reqd.
• Variable capacitor (ganged)
220 PF - 1 No.

PROCEDURE

TASK 1: Construct and test a crystal receiver

1 Identify the windings of the MW antenna coil as

Fig 1
demonstrated by your instructor. Put small paper tags ANTENNA

for the identified terminals. Measure and record the

FERRITE ROD

resistance of the windings in record sheet.

2 Test and record the condition of the given ganged
OA 79
capacitor. 1 3

3 Get the identified windings and condition of the ganged

capacitor checked by your instructor. 100K HEAD
PHONE
220PF
4 Check the condition of the given high impedance
headphone as given below, 2
MW
4
ANTENNA COIL
i) Solder wires to a headphone socket. Insert the
headphone plug into the socket.
ii) Measure the resistance between the terminals of
the headphone. The meter should show a resistance 6 Construct a crystal AM receiver on a general purpose
value as specified by the headphone manufacturer. PC board referring to the circuit diagram given in
Record the specified and measured resistance of Fig 1.
the headphone in Table 1 of record sheet.
7 Put-on the tested headphone. Adjust the position of the
If the meter shows dead-short or open, it is an gang capacitor and tune the crystal receiver to the
indication of a defective headphone. nearest AM radio station.
The volume of reception will be very low as no external DC
5 Check to confirm satisfactory condition of the supply is given to the crystal receiver.
components required to construct a crystal AM receiver
as shown in Fig 1. 8 Adjust the position of antenna coil over the ferrite rod till
you get a better reception. Put a small paper or wooden
wedge to fix the best reception position of the antenna
coil over the ferrite rod.
173
9 Record the station received and the station frequency 11 Get your work checked by your instructor.
in Table 2 of record sheet.
10 Tune the gang capacitor to receive other possible
stations. Record the number of stations received by the
crystal receiver in Table 2 of record sheet.

TASK 2: Add an amplifier to the crystal receiver

1 Refer Fig 2 and add a transistor amplifier to the crystal

Fig 2 + 3V
receiver wired in task-1.
2 Give DC supply and test the receiver’s reception as
done in task-1.
HEAD
3 Repeat step 8 of task-1 to improve the signal reception. PHONE
1MΩ
4 Repeat step 10 of Task 1 to receive the other AM
stations and record in Table 3. 220Ω

5 Get the working of the receiver and recorded data BC148

0.1 μ F
checked by your instructor.
FERRITE ROD

MW ANT COIL
10KPF 10KPF
220PF
GANG

174 IT & ITES : ICTSM - Exercise 1.3.24

 Record Sheet for Exercise 1.3.24

TASK 1

1 Table 1

(a) Manufacturer's specifications of the head phone :

(b) Measured impedance/resistance of the Headphone :_________________ Ohms

2 Table 2

Names of the stations Station Space for recording additional information/data:

received frequency

TASK 2

3 Table 3

Names of the stations Station

received frequency

IT & ITES : ICTSM - Exercise 1.3.24 175

IT & ITES
ICTSM - Basic Electronics Exercise 1.3.25

Construct & test a FM receiver

Objectives: At the end of this exercise you shall be able to
• construct and test a FM receiver using ICs.

Requirements

Tools/Equipments/Instruments • Capacitors Disc

• Trainees kit 15pF - 2 Nos.
• FM microphone (cordless) - 1 No/ 22pF - 1 No.
batch. 330pF - 1 No.
• Regulated power supply 0-30V, 1A - 1 No. 10kpF - 5 Nos.
20kpF - 1 No.
Materials/Components 100kpF - 1 No.
• Printed Circuit Board Code No.PCB X - 1 No. 470μF/16V electrolytic - 1 No.
(Refer appendix-A for actual size PCB layout) • Trimmer 22pF - 1 No.
• IC-LA1185 - 1 No. • IFT Red(FM) - 1 No.
• IC-TBA120S - 1 No. • IFT Grey (suitable for use with IC-120S) - 1 No.
• Resistors /1/4W • Coil L1 (22 SWG/5mm dia/3.5 turns) - 1 No.
27Ω - 2 Nos. • Coil L2 (22 SWG/5mm dia/2.5 turns) - 1 No.
160Ω - 1 No. • Telescope antenna - 1 No.
12KΩ - 1 No.

PROCEDURE

1 Check the given components to confirm their good

Fig 2
working condition. Clean the PCB and keep it ready for
wiring. 9 GND
C11 C12
C5
2 Refer circuit diagram & PCB component layout diagram + V CC
R1 L 2 TR R3 C C
C9 8 10 R4
O/P
shown in Fig 1 & 2 and assemble the FM receiver circuit C4 14
C3
IC-1 - LA1185

L1 IC-2 - TBA120S
C7
Fig 1 C2 1
IC - LA 1185 1
C1 IFT - RED C6 R2 IFT - GREY
(a) 9 8 7 6 5 4 3 2 1
ANT
NC C1
C4 TO FM ANT
C5 22pF C3 C2
10kpF

15pF 15pF 10kpF COMPONENT LAYOUT DIAGRAM OF FM RECEIVER

L2
2.5T
L1
3 Get the wired circuit checked by your instructor.
R1 Trimmer 3.5T

24 Ω 4 Connect the output of the FM receiver to any of the

audio amplifier wired in earlier exercises.
R3 160 Ω R4 24Ω
+ V CC 5 Solder a 2 metre long flexible wire between the antenna
10kpF

C11 12V
input on PCB and a telescopic antenna. Elongate the
10kpF

C9 C12 470μ F

C8
telescopic antenna and place the antenna vertically at
a distance from the receiver board.
14 11 10kpF
IFT RED

13
C10
6 Solder flexible wires for VCC and GND on the receiver
C6 IC - TBA 120S
8
O/P PCB. Connect the wires to a 12V regulated dc supply.
2 4 3 100kpF
9
20kpF
C7 7 Power-on the FM receiver and the audio power ampli-
12 7
5 fier.
330pF
R2
12K
8 Turn the trimmer slowly and gently in very small steps
IFT GREY till the receiver picks up the local FM station.
CIRCUIT SCHEMATIC OF FM RECEIVER

(b)
176
If FM station is not available in your region, take a cordless Speak into the FM microphone while tuning.
FM mic and use it as the FM transmitter.
12 Take the FM microphone away from the receiver and
9 If the reception is feeble or/and noisy, tune the red IFT find out the maximum distance at which the mic signals
followed by grey IFT to get clear and noise free recep- is picked up by the receiver without noise. Record the
tion. approximate distance in record sheet.
10 If the receiver is not getting tuned in spite of carrying out 12 Get your work checked by your instructor.
steps 8 and 9, spread coil L2 slightly and repeat steps
Integrate the wired FM receiver with the TBA/CA 810
8 and 9.
Power amplifier wired in earlier exercise.
11 Repeat steps 8 and 9 to tune the FM receiver to the
FM microphone.

Record Sheet for Exercise 1.3.25

1 Instructors remarks on the correctness and neatness of the wired circuit

Very good Good Satisfactory Poor/Redo

2 Specification of the audio amplifier used to connect the output of FM receiver :

3 Reception of the wired FM Receiver:

(i) Clarity of sound :

(ii) Local FM station received :

(iii) Signal from FM MIC received :

4 Instructors remarks on the working of the FM Receiver:

5 Instructors remarks on the working of FM receiver integrated with the TBA/CA 810 Audio Power amplifier

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.3.25 177

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.01

Identify and test digital IC(s) using IC tester

Objectives: At the end of this exercise you shall be able to
• identify the IC manufacturers name from the logo given on the IC
• identify IC code number printed on the given digital IC
• identify the type of package of the given digital IC
• identify the logic family of the given digital IC referring databook
• identify the level of integration for the given IC referring databook
• identify the pin numbers of the given Digital IC referring data book
• identify the worst case input and output voltage levels for the given digital IC referring data book
• test the given IC using digital IC tester.

Requirements

Tools/Equipments/Instruments Materials/Components
• Digital IC databook - 1 No./batch. • Assorted Digital ICs - 32 Nos.
• Digital IC tester with manual - 1 No./batch of 8.

PROCEDURE

1 Pick one of the labeled IC from the assorted lot and 10 Based on the identified logic family of the IC, find and
record its label number in record sheet. record the following information;
2 From the manufacturers logo printed on the IC, or from – Maximum VCC voltage level that can be applied &
the initial alphabets used for the IC name, identify and permissible tolerance.
record the IC manufacturers name.
– Worst case input and output voltage levels for logic-
Refer data manual to interpret the logo given on the IC or 1 and logic-0 levels.
initial alphabets used for the IC type name.
11 Get the recorded readings checked by your instructor.
3 Identify and record the IC type number printed on the IC.
12 As demonstrated by your instructor, test and record the
4 Get the identified manufacturers name and IC type condition of the IC using digital IC tester.
number checked by your instructor.
Follow the procedure demonstrated by your instructor for
5 Identify and record the IC package type from the setting the controls on digital IC tester while testing the
physical appearance of the IC, or referring to 'IC data IC.
manual'.
13 Get the recorded information of the IC checked by your
6 Identify and record the logic family of the IC referring instructor.
data manual.
14 Repeat steps above for atleast 10 different ICs.
7 Identify and record the level of integration of the IC
referring data manual. You may skip steps 11 and 13 after checking 2 to 3 ICs.

8 Count and record the number of pins on the IC. 15 Get the recorded information checked by instructor.

9 Draw a rough sketch of the IC in record sheet. Identify

and record the 1st pin, last pin VCC and ground pins of
the IC.
Refer data manual for pin details.

178
 Record sheet for Exercise 1.4.01

1 TABLE 1

Sl. Label I.C Type Total Logic Level Worst case Worst case VCC/VDD Status Temperature
No. No. No. of no. of family of i/p voltage o/p voltage max., min. of IC range
package pins integration Logic-0, Logic-1 Logic-0, Logic-1

2 Outline sketch of IC(s) chosen in Table 1.

IT & ITES : ICTSM - Exercise 1.4.01

(Trainee) (Instructor)

179
IT & ITES
ICTSM - Digital Electronics Exercise 1.4.02

Construct and test NOT gate, logic probe and logic level indicator circuits
Objectives: At the end of this exercise you shall be able to
• construct and test NOT gate using discrete components
• verify the truth table of TTL and CMOS NOT gates
• construct and test a logic probe using CMOS NOT gate (CD4079)
• construct and test logic level indicator using TTL NOT gates(7404).

Requirements

Tools/Equipments/Instruments • LED (5mm)

• Regulated DC power supply unit Red - 7 Nos.
5V, 500mA - 1 No. Green - 1 No.
• DC voltmeter(MC) 0-10V/multimeter - 1 No. • IC 7404 (Hex inverter) - 1 No.
• IC 4049 (Hex inverter) - 1 No.
Materials/Components • IC base 14-pin - 1 No.
• General purpose I.C - 1 No. • Multimeter prod tip - 1 No.
test board/Pin Board • Hookup wire (one end is connected
• GPCB for logic probe - 1 No. to crocodile clips)
• GPCB for logic level indicator - 1 No. Red 50cm - 1 No.
(Dot matrix PCB) Black 50cm - 1 No.
• Transistor BC147 - 1 No. Green 30cm - 6 Nos.
• Resistors • Wooden or plastic cut pieces - as reqd.
1 KΩ - 2 Nos. (As per the dimensions given
330Ω - 6 Nos. in Fig 4)
1MΩ - 3 Nos. • Adhesive - as reqd.

PROCEDURE

TASK 1: Construct a NOT gate using discrete components and verify its truth table

1 Construct the NOT gate using discrete components as When the input terminal of the circuit is grounded, it is
shown in Fig 1 on the general purpose PCB. Get it equivalent to applying logic 0. Note that keeping input
checked by your instructor. terminals open is not equal to logic 0 level.
3 Apply logic level-1 to the input (see note below) and
record the voltmeter reading, its equivalent logic level
and the status of LED.
When the input of the circuit is connected to +5V, it is
equivalent to applying logic 1.
4 Repeat steps 3 & 4 a few times to confirm the recorded
values and to have a clear understanding of the logic
levels and concept of inversion logic.

2 Power ON the circuit, by applying 5V as shown in 5 Get the working of the NOT gate and recorded readings
Fig 1. Apply logic level-0 to the input (see note below) checked by your instructor.
and record the voltmeter reading, its equivalent logic
level and the status of LED.

180
TASK 2: Verify the truth table of a TTL NOT gate IC 7404

1 Record the following details for the given IC 7404. 8 Apply Logic 0(Low/Ground/0volt) to the input of the
inverter 1 of wired IC not circuit. Record the output
– Manufacturers name
voltage, corresponding logic level and status of LED in
– IC number Table 1 of record sheet.
– Type of package 9 Give logic 1 (High/+5V) at the input of the same inverter
and record the outputs as done in step 8.
– IC family type
10 Get the recorded readings checked by your instructor.
– Snitch Internal connection diagram with pin numbers.
11 Modify the wiring of the circuit to test the next NOT gate
2 Referring IC data book complete the sentences given
between pins 3 & 4. Get it checked by your instructor.
in record sheet and get it checked by the instructor.
12 Repeat steps 8, 9 and 11 to test other NOT gates of the
3 Test the IC using digital IC tester to confirm its good
IC.
working condition. Exchange IC if found defective.
If any gate is found to be defective, record it and consult
4 Construct the NOT gate test circuit shown in Fig 2 on
your instructor.
the general purpose IC test board/pin board. Get the
constructed circuit checked by your instructor. 13 Get your work checked by your instructor.

Do not dismantle the circuit. This is required

for Task 3.

14 Repeat steps 1 to 12 for the CMOS NOT gate IC,

CD4079 following the instructions given below;
– Construct the circuit in a different place on the same
board.
If you are using GPIC test board, do not insert the IC until – After setting up the circuit get it checked before
all the soldering work is completed. This prevents the IC proceeding further.
from getting damaged due to soldering heat. This note is – Use 12 volts dc for VCC.
not applicable if you are using a bread board or any other
type of Pin board. – For CMOS ICs, Logic-1 can be equal to VCC.
5 Insert the IC in the IC base of the wired circuit. The minimum logic-HIGH
input voltage should be = 2/3 VCC.
Take care while inserting, to avoid pins getting damaged. and, maximum logic-LOW
6 Power on the DC supply (+5V) to the wired circuit and input voltage can be = 1/3 VCC.
check if the IC is getting excessively heated-up. If the 15 Get your word and recorded readings checked by your
IC is getting heated up, switch-off power supply and instructor.
consult your instructor.
7 Measure voltage level at VCC and GND pins at the IC to
confirm that supply is reaching the IC.

TASK 3: Construct and test a logic probe using IC CD4049

1 Test all the components required to construct a logic GPCB means General purpose PCB.
probe circuit as shown in Fig 3. If any component is
found defective get it replaced. 3 Solder a rigid copper wire of 14 or 16 SWG or a broken
tip of multimeter prod on PCB as shown in Fig 3 as the
logic probe tip.
A broken tip of a multimeter prod is more appropriate for
this purpose.
4 Attach a suitable sleeve over the tip of the probe as
shown in Fig 3.
Use the sleeve of a thick single strand wire as probe tip
2 Solder the components of the logic probe on a GPCB sleeve.
strip as shown in Fig 3b.

IT & ITES : ICTSM - Exercise 1.4.02 181

5 Fix solder wick over the sleeve as shield. Ground one The probe is working satisfactory if green LED glows when
end of shield. Put another rubber sleeve over the shield logic 0 is measured and red LED glows when logic 1 is
as shown in Fig 3. measured.
As the input impedance is very high a shielded wire is 14 Repeat checking of the wired probe a few times to
required to connect the probe to the input of IC-1. confirm that it is working satisfactorily.
6 Insert IC CD4079 in the IC base. Check if pin no.1 of IC 15 Get your work checked by your instructor.
4079 is connected to Vdd (5 Vdc) and pin no.8 is
16 Make a handy wooden or a plastic box as per dimen-
connected to ground.
sions given in Fig 4.
7 Solder two lengthy (atleast 1 meter) flexible wires at
Vdd and GND points on the PCB.
8 Get the wired logic probe checked by your instructor.
9 Connect the flexible wire ends to dc supply (5v & GND).
10 Connect the inverter test circuit using 7404 wired at
Task 2 to supply.
Use a different +5V dc supply but, common ground points
for the two circuits.
11 In the inverter circuit wired in task 2, connect the first
Based on the dimensions of the GPCB strip on which the
three inverter input pins (1,3 and 5) to ground (logic 0)
logic probe in wired, alter the dimensions given in Fig 4.
and the other three inverter inputs pins (9,11 and 13) to
+5 volts (logic 1). 17 Mount the PCB in the box such that the Vdd supply (red
wires) and ground (black wires) required for the test
With these inputs, the output of first three inverters (pins
circuit are brought out through small holes provided in
2, 4 and 6) should have logic 1 output and output of the
the box.
remaining three inverters (pins 8,10 and 12) should have
logic 0 output. 18 Test the assembled logic probe.
12 Using the wired logic probe, check and record the 19 Get the satisfactory working of the logic probe checked
outputs of the 7404 inverters in Table 3 of record sheet. by your instructor.
The green led of the probe glows for logic 0 and red led for
logic 1.
13 Based on the recorded readings, give your conclusion
about satisfactory working of the wired logic probe. Get
it checked by your instructor.

TASK 4: Construct and test logic level indicator using IC7404

1 Cut a dot matrix PCB of suitable dimensions as given 3 Solder 20-30 cm long flexible wires at the inputs (QA
in Fig 6. to QF) as shown in Fig 6.
4 Connect the wired board to regulated DC supply. Apply
logic 1 to QA input, observe and record the correspond-
ing LEd’s status in table 4 of record sheet.
For logic 1 input corresponding LED should glow and for
logic 0 the LED should not glow.
5 Get it checked by your instructor.
6 Repeat step 4 for the remaining inputs to confirm
satisfactory working of logic level indicator.
7 Apply different logic level combinations to the input
(example 101010) and check the working of the logic
2 Construct logic level indicator circuit referring to the level indicator.
schematic and layout diagrams as shown in Fig 5 and Record the different combinations of inputs tried while
6. testing in Table 2 of record sheet.
Use IC base and LED holders for wiring. 8 Get the work done by your instructor.

182 IT & ITES : ICTSM - Exercise 1.4.02

 1 Dismantle the wired circuits at Task 1 and Task 2
2 Do not dismantle the logic probe and the logic level indicators as these are extensively used in further
exercises.

Record sheet for Exercise 1.4.02

TASK 1

1 Table 1

Input Output

Logic Voltage Logic Voltage LED

level level level level status
ON/OFF

TASK 2

2 Referring to Fig 2 of exercise and IC data book, notedown the following readings:-
I
a IC number :
b Manufacturer name :
c Number of pins :
d Type of package :
e IC family type :
f Internal block diagram with pin numbers and details

II
1 IC 7404 has got ____________________ inverters.
2 Maximum I/P voltage level for Logic-0 is ____________________ volts.
3 Minimum I/P voltage level for Logic-1 is ____________________ volts.
4 Maximum O/P voltage level for Logic-0 is ____________________ volts.
5 Minimum O/P voltage level for Logic-1 is ____________________ volts.
6 In IC 7404, the VCC and ground pins are ____________________ and ____________________ respectively.

IT & ITES : ICTSM - Exercise 1.4.02 183

 3 Table 2

184
Input Output

Inverter-1 Inverter-2 Inverter-3 Inverter-4 Inverter-5 Inverter-6

Level O/P Logic Status O/P Logic Status O/P Logic Status O/P Logic Status O/P Logic Status O/P Logic status
voltage level of LED voltage level of LED voltage level of LED voltage level of LED voltage level of LED voltage level of LED

Working fully Not fully Not working 5 Instructors remarks Very good Good Satisfactory Poor
satisfactorily satisfied
4 Condition of the assembled
logic probe using IC CD4079

6 Table 3

Applied Input pin No. Output pin No. Output status Conclusion
logic level

Level 0 1 2
Level 0 3 4
Level 0 5 6

IT & ITES : ICTSM - Exercise 1.4.02

Level 1 9 8
Level 1 11 10
Level 1 13 12

7 Table 4

S.No. Input Logic levels for Corresponding LED STATUS

QF QE QD QC QB QA LED-6 LED-5 LED-4 LED-3 LED-2 LED-1
IT & ITES
ICTSM - Digital Electronics Exercise 1.4.03

Construct and test OR, NOR gate and RS flip flop

Objectives: At the end of this exercise you shall be able to
• an OR gate using diodes and verify truth table
• an OR gate using IC-7432 and verify its truth table
• a NOR gate using OR gate (7432) and inverter (7404) and verify its truth table
• a NOR gate using IC-7402 and verify its truth table
• an RS flip flop using NOR gates and verify its truth table.

Requirements

Tools/Equipments/Instruments • LED - 2 Nos.

• Oscilloscope 15 MHz - 1 No. • ICs
• DC power supply 5V - 1 No. 7402 - 1 No.
• General purpose IC test board - 1 No. 7404 - 1 No.
7432 - 1 No.
Materials/Components • SPDT switches - 2 Nos.
• Diode, 1N4007 or any junction diode - 2 Nos. (miniature toggle)
• Resistor • IC base, 14 pin - 2 Nos..
330Ω - 2 Nos.
1kΩ - 1 No.
10kΩ - 2 Nos.

PROCEDURE

TASK 1: Construct an OR gate using discrete components and verify its truth table

1 Refer Fig 1 and wire an OR gate circuit on a general

purpose IC test board/pin board.
2 Apply logic level inputs to A and B of the circuit as given
in Table 1 of record sheet. Record the output logic levels
in each case.
3 Get the recorded readings checked by your instructor.

TASK 2: [a] Construct a quad two input OR gate using IC-7432

1 Record the details of the given IC-7432 in table-2 of

record sheet referring to data manual.
2 Insert the IC-7432 into the IC base of the general
purpose IC test board.
3 Make other circuit connections to the IC as shown in
Fig 2.
4 Set switches S1 and S2 to apply input logic levels as
in Table 3 of record sheet to the first OR gate (Shown
in Fig 2). Record the o/p logic level.
5 Get it checked by your instructor.
6 Repeat step 4 for the other three OR gates of the IC.

185
7 Based on the Recorded output of gates, give your Disconnect connections made at input and output of the
conclusion about the condition of each OR in table-3. gates. Allow the IC 7432 to remain plugged on the board for
subsequent tasks.
8 Get the recorded readings checked up by your
instructor.

TASK 3: [a] Construct and test a NOR gate using IC-7432 and 7404

1 Insert IC-7404 in a IC base placing it next to the earlier

placed 7432 (Refer Fig 3) Interconnect IC7432 and 7404
to form a NOR gate as shown in Fig 3a and 3b. Get the
wired circuit checked by your instructor.
2 Connect 5V regulated dc supply to the wired circuit.
3 Apply input logic levels as given in Table 4 of record
sheet for the first OR gate and record the o/p logic level
for each set of input conditions.
4 Get it checked by your instructor.
5 Repeat step 1 and 3 by connecting the other OR gates
of the IC.
6 Get your work checked by your instructor.

[b] Verification of truth table of quad, two-input NOR gate IC-7402

1 Record the details of the given IC7402 (NOR gate) 3 Connect 5V dc supply to the IC as shown in Fig 4.
referring data manual in Table 2 of record sheet.
4 Apply input logic levels as given in Table 5 of record
2 Insert the NOR gate IC-7402 in a IC base of general sheet for the first NOR gate. Record the output logic
purpose IC test board/ pin board. Make circuit level.
connections as shown in Fig 4.
5 Get it checked by your instructor.
6 Repeat step 4 for the remaining NOR gates of the IC.
7 Record the condition of each NOR gate after verifying
the recorded truth table.
8 Get your work checked by your instructor.
Remove all circuit connections except IC7402 to carryout
subsequent tasks.

TASK 4: Construction of RS-flip flop using NOR gate and verification of its truth table

1 Interconnect the inputs and output of NOR gates of 2 Get the connections checked by your instructor.
IC7402 referring the schematic diagram shown at Fig 5.
3 Connect +5V dc supply to the wired circuit.

186 IT & ITES : ICTSM - Exercise 1.4.03

 4 Apply input logic levels to the wired circuit using NOR
gates as given in Table 6 of record sheet. Record the
output level at Q for different input conditions.
5 Get your work checked up by your instructor.
Remove all the connections except IC7402 to carryout
subsequent tasks.

TASK 5: Construction of an astable multivibrator using NOR gates

1 Wire an astable multivibrator referring to the circuit 3 Using a CRO, measure and record (in Table 7) the
shown in Fig 6 on the same IC test board used in the frequency of the output waveform.
previous task. Get the wired circuit checked by instructor.
4 Measure and record all other pulse parameters of the
output wave for using an oscilloscope.
5 Calculate and record (in table 7) the theoretical fre-
quency of oscillation based on the value of circuit
components used.
6 Make a rough sketch of the output wave form in table-
7.
7 Get the recorded data and the performance of the circuit
checked by your instructor.
2 Connect +5V dc supply to the circuit.

Record sheet for Exercise 1.4.03

TASK 1

1) Table 1

Truth table of OR-gate using diodes

Logic Input Logic Output

A B Y=A+B

0 0

0 1

1 0

1 1

open open

[NC=no connection]

IT & ITES : ICTSM - Exercise 1.4.03 187

2) Table 2

I.C Type Total Worst case Worst case VCC/VDD Status Temperature
No. of no. of i/p voltage o/p voltage of IC range
package pins Logic-0 Logic-1 Logic-0 Logic-1 max. min.

7432

7402

TASK 2 5) Table 5

3) Table 3 (b) Truth Table of NOR gate (7402)

Input Output Logic at Pin No.
Truth table of OR-gate using IC7432
A B 1 4 10 13
Logic Input Output logic at Pin No.
0 0
A B 3 6 8 11
0 1
Gate-1 Gate-2 Gate-3 Gate-4
1 0
0 0
1 1
0 1
Condition of gate :
1 0
6) Table 6
1 1
Condition of gate in the IC : R-S flip-flop using 7402
R S Q State
0 0 Last state (Latch)
TASK 3
0 1 Set
4) Table 4
1 0 Reset
(a) NOR gate using OR (7432) and NOT (7404) gates 1 1 Forbidden

Logic Input Logic Output 7) Table 7

A B Y=A+B Astable multivibrator using NOR gates

(status of LED)
Theoretical/ Measured Shape of the
0 0 Calculated output output waveform
frequency frequency
0 1 1
1 0 f = ———
1.4RC
1 1

Other parameters of the output pulse:

(Trainee) (Instructor)

188 IT & ITES : ICTSM - Exercise 1.4.03

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.04

Construct and test circuits of AND, NAND and EX-OR gates

Objectives: At the end of this exercise you shall be able to
• AND gate using diodes
• AND gate using IC7408
• NAND gate using IC7408 and 7404
• NAND gate using IC7400
• EX-OR gate using IC7404, 7408 and 7432
• EX-OR gate using IC7486.

Requirements

Tools/Equipments/Instruments • LED, red - 1 No.

• Regulated DC power supply, +5V - 1 No. • IC7408 Quad AND GATE - 1 No.
• IC7404 Hex inverter - 1 No.
Materials/Components • IC7400 Quad NAND GATE - 1 No.
• IC7432 Quad OR GATE - 1 No.
• Bread board - 1 No. • IC7486 Quad EX-OR GATE - 1 No.
• Diodes, 1N4001 - 2 Nos. • 14 pin IC base - 3 Nos.
• Resistors • Toggle switches - 2 Nos.
1KΩ - 1 No. • Press switch - 1 No.
330Ω - 1 No.

PROCEDURE

TASK 1- (a) Construct AND gate using discrete components & verify truth table

1 Refer Fig 1 and construct the AND gate circuit using

discrete components on a pin board/bread board.
2 Get wired circuit checked by your instructor.
3 Apply different logic levels to the inputs A & B as given
in Table 1 of record sheet. Record the corresponding
output logic level and LED status.
4 Get your work checked by your instructor.

(b) Construct and test an AND gate using IC(7408)

1 Make circuit connections referring to Fig 2 using IC
7408 (AND).
2 Apply different logic levels to the inputs A and B to gate-
1 (between pins 1 & 2) and record output (pin 3).
3 Repeat step 3 for the other AND gates in the IC by
suitably modifying the circuit at input & output.
4 Conclude the condition of the IC in record sheet after
verifying truth table.
5 Get it checked by your instructor.

189
TASK 2: (a) Construct a NAND gate circuit using an AND gate IC-7408 and a NOT gate IC-7404 and verify its
truth table

1 Wire a NAND gate using AND gate(7408) and NOT(7404)

gate referring to Fig 3a and 3b.
2 Get the circuit connections checked by your instructor.
3 Power on +5V regulated DC supply to the circuit.
4 Apply different logic levels at the inputs A & B as given
in Table 3 of record sheet. Record the corresponding
output logic level and status of the output LED.
5 Get the work checked by your instructor.

(b) Construct and verify the truth table of NAND gate using IC 7400

1 Wire a NAND Gate circuit using IC7400 by referring Fig

4.
2 Power on +5V regulated DC supply to the circuit.
3 Apply different logic levels at the inputs A & B as given
in Table 4 of record sheet. Record the corresponding
output logic level and LED status.
4 Repeat step 3 for the remaining NAND gates in the IC
by suitably modifying the circuit at input and output.
5 Record your conclusion about the condition of the
NAND gate in table-4.
6 Get your work checked by your instructor.

TASK 3: Construct an EX-OR gate circuit using NOT gate IC7404, AND gate IC7408 and OR gate IC7432

1 Wire an EX-OR gate using, a NOT gate (7404), an AND 4 Apply inputs A and B as given in Table 5 of record sheet.
gate (7408) and an OR gate (7432) referring to the Record the corresponding output logic level and LED
schematic shown in Fig 5a and Fig 5b. status.
2 Get the circuit connections checked by your instructor. 5 Get the work checked by your instructor.
3 Power on +5V DC supply to circuit.

190 IT & ITES : ICTSM - Exercise 1.4.04

(b) Verify the truth table of EX-OR gate using IC7486

1 Wire an Ex-OR Gate as shown in Fig 6 using IC7486. 2 Power on +5V regulated DC supply to the circuit.
3 Apply inputs A and B as given in Table 6 of record sheet.
Record the output logic level and LED status.
4 Repeat step 3 for the remaining EX-OR gates in the IC
by suitably modifying the circuit at the input and output.
5 Based on the recorded truth table. Give your conclusion
about the condition of the checked EX-OR gate IC.
6 Get it checked by your instructor.

IT & ITES : ICTSM - Exercise 1.4.04 191

 Record sheet for Exercise 1.4.04

1 Table 1

(a) Truth table of AND gate using discrete components

Input Output

Logic level Equivalent Logic level Voltage LED status

A B voltage level level (ON/OFF)
given as inputs
at A and B

0 0

0 1

1 0

1 1

open open

(b) Table 2

Truth table of AND gate IC-7408

Input Output Y = AxB

Logic level Y1 Y2 Y3 Y4
A B (pin 3) (pin 6) (pin 8) (pin 11)

0 0

0 1

1 0

1 1

Condition of gate

2 Table 3

(a) NAND gate using ICs 7408 and 7404

Input Output

Logic level Y=A.B Status of

A B output LED

0 0

0 1

1 0

1 1

192 IT & ITES : ICTSM - Exercise 1.4.04

(b) Table 4

Truth table of NAND Gate using IC7400

Input Output

Logic level Logic level Y=AB

A B Y1 Y2 Y3 Y4
Pin 3 Pin 6 Pin 8 Pin 11

0 0

0 1

1 0

1 1

Condition of gate

3 Table 5

(a) Truth table of Ex-OR gate using IC's7404, 7408 and 7432

Input Output

Logic level Y=A+B Status of

A B = AB + AB output LED

Pin 3

0 0

0 1

1 0

1 1

(b) Table 6

EX-OR gate using IC7486

Input Output
Logic level Y = A + B = AB + AB
A B Y1 Y2 Y3 Y4
Pin No.3 Pin No.6 Pin No.8 Pin No.11
0 0

0 1

1 0

1 1

Condition of gate:

IT & ITES : ICTSM - Exercise 1.4.04 193

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.05

Construct and test the circuits of R-S flip-flop and D flip flop using NAND
Objectives: At the end of this exercise you shall be able to
• construct an inverter using NAND gate and test it
• construct and verify the truth table of S-R flip-flop using NAND gate IC7400
• construct and verify the truth table of clocked S-R flip-flop
• construct and verify the truth table of clocked D-flip-flop by modifying clocked SR flip-flop.

Requirements

Tools/Equipments/Instruments Materials/Components
• DC power supply, 5V - 1 No. • Bread board - 1 No.
• General purpose PCB - 1 No./batch
• IC-7400 NAND gate - 5 Nos.
• IC base 14 pin - 5 Nos.

PROCEDURE

TASK 1: Construct an inverter using NAND gate(7400)

1 Refer Fig 1 and wire the circuit on a `Bread board’. 3 Apply logic levels as shown in Table 1 of record sheet
2 Get it checked by your instructor. and record the corresponding output logic levels and
status of LED in Table 1 of record sheet.
4 Conclude the status of the gate in record sheet after
verifying truth table.
5 Get it checked by your instructor.
Remove the all connections except IC7400 to carryout
subsequent task.

194
TASK 2: (a) Construct a S R flip flop' circuit using NAND gate(7400)

1 Wire a S R` flip flop' circuit by interconnecting two

NAND gates referring to Fig 2a and 2b on a circuit bread
board.
2 Get it checked by your instructor.
3 Apply different inputs to R and S as given in Table 2 of
record sheet and record the corresponding output levels
and the status of LED.
With =0 (S=1) and =0 (R=1), the output states are
undeterminable hence they are referred as Forbidden.
4 From the recorded output in table, indentify the forbid-
den input states to the FF.
5 Get your work checked by your instructor.
Keep the wired circuit undisturbed in order to carryout
Task 3.

(b) Construct and Test a D-latch

1 Refer Fig 3 and modify the circuit at Fig 2 to construct 2 Get the wired circuit checked by your instructor.
a D-latch.
3 Apply input logic levels as given in Table 3 of record
sheet and record the output Q and status of LED.
4 Get it checked by your instructor.

(c) Construct and test a Debouncer circuit

1 Modify the circuit at Fig 3 to that shown in Fig 4 to make 3 Connect the output(Q) of the circuit to oscilloscope.
a debouncer circuit.
3 Press the push button switch once, measure and
record the Q-output logic level in Table 4 of record sheet.
4 Press the push button switch once again and record the
Q-output logic level in Table 4 of record sheet.
5 Press the push button switch repeatedly and observe
the waveform on CRO. Record your observations in
record sheet.
6 Get the working of the debouncer circuit checked by
your instructor.

2 Get modified circuit checked by your instructor.

IT & ITES : ICTSM - Exercise 1.4.05 195

TASK 3: Construct single shot pulser (One shot) using NAND(7400)

1 Wire the single shot pulser circuit using NAND gates 5 Change switch S to position 2 and record the status of
referring to Fig 5, on a small strip of general purpose PC LED in Table 5 of record sheet. Record the logic status
board. at the output of pulser on CRO.
6 Repeat steps 4 and 5 a few more times to confirm that
the recorded status of output with the switch pressed/
released are correct.
7 Get it checked by your instructor.
8 Change the position of switch S repeatedly and observe
and record the status of output of pulser.
9 Get the work checked by your instructor.
2 Get the wired circuit checked by your instructor. Keep end product of Task 3 undisturbed to carryout Task
5.
3 Connect the output of the pulser to CRO.
4 Power on the circuit, press and hold the switch S in
position 1 and record the status of LED in Table 5.
Measure and record the output of pulser on CRO.

TASK 4: Construct a `S-R flip-flop' using NAND gate Ic7400 and verify truth table

1 Wire a S-R flip-flop on a bread board using NAND gate 2 Get wired circuit checked by instructor.
(IC7400) referring to Fig 6.
3 Apply different input logic levels to the S-R flip-flop as
shown in Table 6 and record corresponding output
levels.
Use the logic probe constructed at Ex.1.4.02 to measure
the output logic level.
4 Get the working of the S-R flip flop checked by your
instructor.

TASK 5: Construct a `Clocked SR flip-flop' by modifying the wired circuit at Task 4

1 Refer Fig 7 and modify the S-R flip-flop wired at Task 4 This pulser is used to provide clock pulses to the wired
into a clocked S-R flip-flop. clocked S-R flip flop.
3 Apply different inputs to R and S with a clock pulse
using the pulser as given in Table 7 of record sheet and
record the output levels.
4 Get the working of the circuit checked by your
instructor.
5 Record the function performed by the clock pulse from
the record observations in Table 7.
2 Get wired circuit checked by instructor. Do not disconnect this circuit as this circuit with minor
modifications is required for the next task
3 Connect the output of the single shot pulser (wired at
Task 3) at clock (chk) input of Fig 7.

196 IT & ITES : ICTSM - Exercise 1.4.05

TASK 6: Construct a D flip-flop

1 Modify the clocked S-R flip-flop constructed in Task 5 3 Set D=1, without applying a clock pulse. Measure and
into a D-flip-flop by adding one more NAND gate as record the output Q.
shown in Fig 8.
4 With D=1, (same as step 2) apply a clock pulse.
2 Get wired circuit checked by instructor. Measure and record output Q.
5 Get it checked by your instructor.
6 Repeat steps 2 and 3 by setting D=0.
7 Record the function of clock pulse form observations
made in Table 8.
8 Get your work checked by your instructor.

Record sheet for Exercise 1.4.05

TASK 1 (b) Table 3

1 Table 1 D-latch

IN Output Input Output Status

Logic level Status of Logic level at D Q of LED
LED
1
1
0
0
1
Condition of the gate: 0
open

Working Redo (c) Table 4

Satisfactory
Status of the wired circuit Debouncer circuit

2 Table 2 Push button Out of Debouncer

action
(a) flip flop using NAND gates Pressed once

Q LED status Pressed again

0 1 Pressed repeatedly

1 0
1 1
0 0

IT & ITES : ICTSM - Exercise 1.4.05 197

3 Table 5 6 Observation about the function of clock pulse at

Single shot logic pulser Table 7 __________________________________

Switch LED Waveforms

status status on CRO 7 Table 8

Position 1 Clocked D-flip-flop

Position 2
Input Output
Position 1 CLK D Q
Position 2 Given 1

Repeated switched Not given 1

Not given 0

Given 0
4 Table 6

SR flip-flop using NAND gate 8 Observation about the function of clock pulse at

R S Q Status Table 8 __________________________________

Set/Reset/
No change/Forbidden 9 Space for recording additional information/ data/
0 1 waveforms.
0 0
1 0
0 0
1 1

5 Table 7

Clocked RS flip-flop

Input Output
Clock S R Q
0 0 0
0 0 1
0 0 1
0 0 1

W 0 0
W 0 1
W 1 0
W 1 1

198 IT & ITES : ICTSM - Exercise 1.4.05

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.06

Construct and test J-K flip-flop and counter

Objectives: At the end of this exercise you shall be able to
• construct a J-K flip-flop using NAND gates
• verify the truth table of J-K flip-flop IC7476
• construct and test a 4 bit asynchronous/ripple binary counter using J-K FF(IC7476)
• modify a 4 bit counter into ÷10 ripple counter.

Requirements

Materials/Components • Resistor, 330Ω - 5 Nos.

• LED - 4 Nos.
• Solderless circuit Bread board - 1 No.
• Push button switch - 1 No.
• ICs 7410 (3 I/P NAND) - 2 Nos.
• Single shot pulser - 1 No.
7476 (J-K Flip-flop) - 2 Nos.
7400 (AND) - 1 No.

PROCEDURE

TASK 1: Construct J-K flip-flop using 3 input NAND gate using IC7410

1 Refer Fig 1 and wire a J-K flip flop using NAND gates 3 With clock input at logic-0, apply; Pr=1 and Cr=0.
on a solderless bread board. Get the wired circuit Measure and record the logic level at output Q.
checked by your instructor.
4 Repeat steps 2 and 3 to get a better feel about the
function of the Pr (Preset) and Cr (Clear) inputs.
5 From the observation made at Steps 2,3 and 4 com-
plete the sentences given in record sheet. Get it
checked by your instructor.
6 With the asynchronous and synchronous inputs given
as in Table 2, apply a clock pulse for each combination
of inputs one by one and record the corresponding Q-
outputs.
With J=K=1, apply clock pulses atleast 4 times to find out
2 With the clock input kept at logic-0, apply preset (pr)=0 that the output Q toggles (1<->0).
and clear (Cr)=1. Measure and record the logic level at
output Q in Table 1 of record sheet. 7 Get the working of the J-K flip flop checked by your
instructor.
Note that the preset and clear inputs are active
low inputs. Hence they are indicated as
(preset-bar) and (clear-bar).

TASK 2: Verify the truth table of J-K flip flop using IC-7476

1 Record the following details for the IC-7476 with the 2 Draw the test circuit diagram in record sheet for testing
help of a data book: IC7476 using any one of the two available J-K flip flop
– Manufactures name in IC7476.

– Package type 3 Get the circuit diagram checked by the instructor.

– Atleast two equivalents 4 Wire the test circuit on a solderless bread board.

– Internal connection diagram with pin numbers 5 Give inputs as given in Table 3. Measure and record the
output logic states.
– Maximum +ve supply
6 Get your work checked by instructor.

199
TASK 3: Construct and test a 4-bit asynchronous/ripple J-K FF Binary counter using (IC-7476)

1 Wire a ripple binary counter on a solderless bread 6 Get the recorded readings checked by your instructor.
board referring to the circuit shown in Fig 2.
4-Bit asynchronous binary counter as a ÷15 counter
2 Get the wired circuit checked by instructor.
7 Repeat steps 3 to clear the outputs of all flip-flops.
3 Switch on +5V regulated DC power supply. Press
CLEAR push button switch once, to clear the outputs 8 Observe output Q3(LED-4) and give pulses at the input
of all flip flops. Record the Q-outputs (Q0 to Q3) of all the counting the pulses till output Q3(LED-4) turns-on and
4-flip flops based on the LEDs status (ON\OFF) in turns-off. Record the counted number of pulses in
Table 4 of record sheet. record sheet.

4 Apply one clock pulse at the input (first flip-flop) using 9 Repeat steps 7 and 8 to confirm the number of pulses
the single shot pulser (fabricated in Ex:1.4.05). Record counted for output Q3 (LED-4) to go high and then go
the output logic levels and the status of LED’s A,B,C,D low.
in Table 4. 10 Get the working of the circuit and recorded readings
5 Repeat step 3 and record the output logic levels for 15 checked by the instructor.
successive clock pulse inputs and record output logic
levels & the status of LED(s) after giving each clock
pulse at the input.

TASK 4: Modify the ÷16 counter into ÷10 ripple counter

1 Modify the circuit connections made at Fig 2 by adding If the ÷10 counter is functioning satisfactorily, after this
a 7400 NAND gate by referring to the circuit given at Fig step the outputs of FFs should become 0. If this is not
3. happening consult your instructor.
2 Press the CLEAR push button switch once to clear the 6 Get the work checked by your instructor.
output of all four FFs. Record the LEDs status and the
7 Repeat steps 2,3,4 and 5 till you are satisfied with the
state of flip flops in Table 5 of record sheet.
working of the ÷10 ripple counter.
3 Apply one clock pulse at the input (clock of FF-1) using
8 From the skills learnt in modifying a ÷16 counter to ÷10
the single shot logic pulser. Record status of LEDs and
counter and from the knowledge acquired in related
the state of flip flops in Table 5 of record sheet.
theory sessions, modify the ÷10 counter into a ÷12
4 Repeat step 3 till the outputs displayed by LEDs is counter and check its working. Record your observa-
equivalent to decimal 10 or binary 1010. While giving tions in table 6.
pulses count the number of pulses given. Record the
9 Get your work checked by the instructor.
number of pulses given in record sheet.
5 Give one more pulse at the input. Observe and record
output of the FFs and the status of LED(s).
200 IT & ITES : ICTSM - Exercise 1.4.06
 Record sheet for Exercise 1.4.06

1 Table 1 (b) Complete the sentences given below:

J-K flip flop using NAND gate
i The output of the J-K FF gets set when
(a) Set/reset using preset/clear inputs Pr=_______________ and Cr=_______________.

CK Pr Cr Q ii To reset the output of J-K FF _______________

= 0 and _______________ = 1.
0 0 1
0 1 0

2 Table 2
Truth table of J-K flip flop

Inputs Output
Asynchronous Synchronous Clock Q
Pr Cr J K

1 1 0 0
1 1 0 1
1 1 1 0
1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1

IT & ITES : ICTSM - Exercise 1.4.06 201

TASK 2 (c) Table 3
Truth Table of J-K flip flop IC-7476
3
(a) Inputs Output
Manufacturers name : Pr Cr J1 K1 J2 K2 Clock Q1 Q2
Package type :
VDC max : 0 1 x x x x x
Equivalents : 1 0 x x x x x
(i)
(ii) 1 1 0 0 0 0 ¯
1 1 0 1 0 1 ¯
Space for pin diagram 1 1 1 0 1 0 ¯
1 1 1 1 1 1 ¯

(b) Space for test diagram

TASK 3

4 (a) Table 4

Input Status of LED ON/OFF Binary output

Clear Input
(clock of FF-1) A B C D Q0 Q1 Q2 Q3
Press once x
High 1
High 2
High 3
High 4
High 5
High 6
High 7
High 8
High 9
High 10
High 11
High 12
High 13
High 14
High 15
High 16

202 IT & ITES : ICTSM - Exercise 1.4.06

(b) No. of pulses given at input for LED-4 (output Q3) to turn-ON and turn-OFF: __________________pulses.

5 Table 5
÷ 10 ripple counter

Input Status of LED(s) Binary output Decimal equivalent

Clear Input
(clock of FF-1) A B C D Q0 Q1 Q2 Q3
Press once x
High 1
High 2
High 3
High 4
High 5
High 6
High 7
High 8
High 9
High 10

6 Table 6
÷ 12 ripple counter

Input Status of LED(s) Binary output Decimal equivalent

Clear Input
(clock of FF-1) A B C D Q0 Q1 Q2 Q3
Press once x
High 1
High 2
High 3
High 4
High 5
High 6
High 7
High 8
High 9
High 10
High 11
High 12

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.4.06 203

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.07

Construct and test an UP/DOWN decade counter using 74LS190

Objectives: At the end of this exercise you shall be able to
• construct an up/down counter using IC 74LS190
• test the counter for counting UP and counting DOWN.

Requirements

Tools/Equipments/Instruments Materials/Components
• Regulated power supply +5V - 1 No. • Solderless circuit bread board - 1 No.
• Logic probe - 1 No. • IC74LS190 - 1 No.
• Single shot pulser - 1 No. (Up/down decade counter)
• LED (Red, green, amber, yellow) - 1 No. each.
• Resistors 220Ω - 4 Nos.
• Switches SPDT - 2 Nos.

PROCEDURE

TASK 1: Construct UP/DOWN decade counter using 74 LS190

1 Refer Fig 1 and wire the circuit of a up/down decade

counter on a solderless bread board using IC74LS190.
2 Get the wired circuit checked by your instructor.

TASK 2: Set the decade counter to count-up and test

1 Give +5V regulated DC supply to the circuit. 5 Measure and record (in table-1) the logic levels at Q3,
2 Apply logic-0 to the control pin D/ to make the counter Q2, Q1, and Q0 using the logic probe.
count-up. 6 From the recorded readings at steps 4 and 5 conclude
whether the counter is counting-up or down.
3 Apply logic 0 to the pins D0 to D3. Apply logic-0 to the
control pin momentarily and raise it back to Logic- 7 Get the recorded output and your conclusion checked
1 state. by your instructor.
This sets output Q3, Q2, Q1, Q0 to logic-0 levels. 8 Repeat steps 3, 4, 5 and 6 to recheck satisfactory
working of the counter.
4 Refer Table 1 of record sheet and feed clock pulses at
clock input (pin 14) using single shot pulser. Record the 9 Get the working of the down counter and the recorded
status of LED(s) at outputs Q3, Q2, Q1 and Q0. readings at table-1, checked by your instructor.

204
TASK 3: Set the decade counter to count-down and test

1 Feed D3, D2, D1 and D0 with 1001 (binary 9) by 4 Refer Table 2 of record sheet and feed clock pulses at
applying suitable voltage levels (logic-1=+5V and logic- clock input (Pin 14). On feeding each clock pulse record
0=0V). the output Q3, Q2, Q1 and Q0.
2 Apply logic-0 to input (pin-11) momentarily and 5 From the recorded readings at step 4, conclude whether
raise it back to logic-1 level. the counter is counting-up or counting-down.
This sets the outputs Q3, Q2, Q1 and Q0 to 1001 such that 6 Repeat steps 1 to 5 to recheck satisfactory working of
this becomes the starting value for the down counter. the down-counter.
3 Apply logic-1 to D/U (Down/Up, pin 5) such that the 7 Get the working of the circuit and the recorded output
counter is prepared for count-down operation. checked by your instructor.

Record sheet for Exercise 1.4.07

1) Table 1a
Up counter

D/ Clock Status of LED(S)

Pin No.5 input Pin No.11 D0 D1 D2 D3 Q3 Q2 Q1 Q0 A B C D
Pin No.14
0 x 1®0®1 0 0 0 0
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
0 - 1 x x x x
Conclusion: _________________________________
2) Table 2

D/ Clock Status of LED(S)

Pin No.5 input Pin No.11 D0 D1 D2 D3 Q3 Q2 Q1 Q0 A B C D
Pin No.14
x x 1®0®1 1 0 0 1
1 - 1
1 - 1
1 - 1
1 - 1
1 - 1
1 - 1
1 - 1
1 - 1
Conclusion : _________________________________

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.4.07 205

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.08

Construct and test a Half adder & Full adder circuits

Objectives: At the end of this exercise you shall be able to
• construct and test half adder
• construct and test full adder using half adder circuits
• construct and test 4-bit binary adder.

Requirements

Tools/Equipments/Instruments • IC-7483 with base - 1 No.

• LED - 2 Nos.
• Trainees kit - 1 No.
• Resistors 330 Ohms,carbon film 1/4w - 2 Nos.
• DC power supply 5V/500 mA - 1 No.
• Switch SPST (light duty) - 3 Nos.
Materials/Components • Bread board - 1 No.
• IC-7486 with base - 1 No. • Solder, flux - as reqd.
• IC-7400 with base - 1 No. • Connecting wires - as reqd.

PROCEDURE

TASK 1: Construction and testing of half adder circuit

1 Construct an half adder circuit as given in Fig 1 on the

given general purpose IC test board .

2 Refer Fig 2 and construct a binary input module for 4 Insert the IC in their respective IC base and switch ON
applying binary inputs to the circuits wired in this the supply.
exercise.
5 Apply the input logic states as given in Table 1 of Record
3 Get the work checked by your instructor. sheet and record the output logic levels.
6 Get the work checked by your instructor.

TASK 2: Construction and testing of full adder using half adder circuits

1 Construct a full adder circuit as given in Fig 3 on a IC test 3 Get the work checked by your instructor.
board.
4 Apply the digital data input as given in Table 2 of Record
2 Connect the binary input module wired in the previous sheet and record the o/p logic levels.
task to the binary inputs of Fig 3.
5 Get your work checked by your instructor.

206
TASK 3: Testing of 4-bit binary adder using IC7483

1 Plug-in the IC7483 onto a general purpose IC test board Use binary input module available on any Digital IC trainer
making use of IC base. kit to provide eight binary inputs required to perform this
2 Connect the carry input pin 13 to logic low. task.

3 Connect the binary input module to the binary inputs of 4 Get your work checked by your instructor.
Fig 4. 5 Apply the first set of digital data inputs at A0 to A3 and
B0 to B3 as given in Table 3 of Record sheet.
6 Test and verify whether you are getting the same o/p
logic levels as given in the Table.
7 Repeat step 6 for different sets of inputs at A0 to A3 and
B0 to B3.
8 Get your work checked by your instructor.

IT & ITES : ICTSM - Exercise 1.4.08 207

 Record sheet for Exercise 1.4.08

1 Table 1

Input Output
A B Sum Carry

0 0
0 1
1 0
1 1

2 Table 2
Input Output
A B C Sum Carry

0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1

3 Table 3

Input Output (with Cin=0)

A B Carry Sum
A3 A2 A1 A0 B3 B2 B1 B0 Cout S3 S2 S1 S0

0 1 0 1 0 1 1 1 0 1 1 0 0
1 0 0 1 0 1 1 0 0 1 1 1 1
1 0 1 1 1 0 1 0 1 0 1 0 1
0 1 1 1 1 1 0 1 1 0 1 0 0
0 1 0 0 1 0 1 0 0 1 1 1 0

(Trainee) (Instructor)

208 IT & ITES : ICTSM - Exercise 1.4.08

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.09

Construct and test a Half subtractor & Full subtractor circuits

Objectives: At the end of this exercise you shall be able to
• construct and test half subtractor
• construct and test full subtractor.

Requirements

Equipments/Components • DC power supply (5V)

• Red/Green LEDs - 2 Nos.
• Resistor (1K) - 5 Nos.
• Connecting wires
• ICs (XOR-7486, AND-7408,
• Breadboard
OR-7432, NOT-7404)
• A surface mount dip switch

PROCEDURE

TASK 1: Construction and testing half subtractor

1 Construct an half subtractor circuit as given in Fig 1 on

the given bread board.
2 Connect the ICs properly to power supply (pin 14) and
ground (pin 7) following the schematics for different ICs
as shown in Fig 3 .
3 Using dip switch and resistors, facilitate all possible
combinations of inputs from the power supply.
4 Turn on power to your experimental circuit.
5 For each input combination, note the logic state of the
outputs as indicated by the LEDs (ON = 1; OFF=0), and
record the result in the table 1.
6 Compare your results with the truth table for operation.
7 When you are done, turn off the power to your
experimental circuit.

TASK 2 : Construction and Testing full subractor

1 Construct an full subractor circuit as given in Fig 2 on 4 Turn on power to your experimental circuit.
the given bread board.
5 For each input combination, note the logic state of the
2 Connect the ICs properly to power supply (pin 14) and outputs as indicated by the LEDs (ON=1; OFF=0), and
ground (pin 7) following the schematics for different ICs record the result in the table 2.
as shown in Fig 3.
6 Compare your results with the truth table for operation.
3 Using dip switch and resistors, facilitate all possible
7 When you are done, turn off the power to your
combinations of inputs from the power supply.
experimental circuit.

209
 Record sheet for Exercise 1.4.09

Table 1 Table 2

Half Subtractor Full Subtractor

A B Q BIN BN-1 A B Q BIN

0 0 0 0 0

0 1 0 0 1

0 1 0
1 0
0 1 1
1 1
1 0 0

1 0 1

1 1 0

1 1 1

210 IT & ITES : ICTSM - Exercise 1.4.09

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.10

Construct and test Multiplexer and demultiplexer circuits

Objectives: At the end of this exercise you shall be able to
• construct and test a multiplexer circuit using IC74LS151
• construct and test a demultiplexer circuit using IC74LS138.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit - 1 No. • IC(s)74LS151 with base - 1 No.
• Regulated DC power supply 5V/500mA - 1 No. 74LS138 with base - 1 No.
• Logic probe - 1 No. • SPDT (miniature toggle) - 8 Nos.
• General purpose IC test board - 1 No.
• Solder, flux - as reqd.
• Connecting wires - as reqd.

PROCEDURE

TASK 1: Construct a multiplexer circuit using IC74LS151

1 Solder a 16 pin IC base into the given general purpose

IC test board.
2 Refer Fig 1 and connect the SPDT switches to different
data and select input pins.
3 Connect enable input pin no.7 and ground pin no.8 to
ground.
4 Insert the multiplexer IC74LS151 onto the soldered IC
base.
5 Get the work checked by the instructor.

TASK 2: Test the multiplexer

1 Connect 5V DC supply and ground to the corresponding 4 Apply different select input sequences at C, B and A
pins of multiplexer IC. referring to Table 1 of Record sheet and record the
2 Apply a pattern of logic level inputs as given in Record status of output at pin no.5 correspondingly.
sheet to eight different data input pins D0 to D7 with the
help of SPDT switches. Note that by changing the select input sequence
at C,B and A one of the eight data inputs is
3 Apply 000 to the select inputs pins C,B and A and passed onto the output.
record the status of output at pin 5 in the Record sheet.
5 Get the work checked by your instructor.
Note that the logic level applied at D0 is now
available at output pin 5. 6 Test the functionality of multiplexer by repeating steps
2 to 5 for different pattern of data inputs.

211
TASK 3: Construct and test a Demultiplexer circuit using IC74LS138

1 Refer Fig 2 and modify the wiring of PCB using in 2 Apply a logic level to data input at pin no.6.
previous task to construct a demultiplexer circuit.
3 Observe the output at Y0 i.e at pin no.15 by applying a
000 to select input pins C,B and A at 3,2 and 1 and
record the status of all outputs Y0 to Y7 in Record sheet.
4 Repeat step 2 and 3 by changing logical level input at
pin no.6.
5 Get the work checked by your instructor.
6 Apply different select input sequences at C,B and A
referring to Table 2 of Record sheet and record the
status of all outputs Y0 to Y7.

Note that the data bit given as input is transmitted

to one of the output lines, depending on the
select sequence applied at C, B and A.

212 IT & ITES : ICTSM - Exercise 1.4.10

 Record Sheet for Exercise 1.4.10

1 Table 1

Pin No. Data inputs Select sequence Output

D0 D1 D2 D3 D4 D5 D6 D7 C B A Y

1 0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0

2 0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1

2 Table 2

Pin No. Data input Select sequence Output

Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C B A

0
1 0 0 0

0
1 0 0 1

0
1 0 1 0

0
1 0 1 1

0
1 1 0 0

0
1 1 0 1

0
1 1 1 0

0
1 1 1 1

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.4.10 213

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.11

Construct and test an analog to digital converter

Objectives: At the end of this exercise you shall be able to
• construct an analog to digital converter circuit using IC0809
• test and verify the analog to digital conversion circuit using IC0809.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees kit - 1 No. • IC ADC0809 - 1 No.
• DC power supply 0-5V/500 mA - 2 Nos. • General purpose IC test board - 1 No.
• Pulse generator, 100kHz - 1 No. • Toggle switch (miniature type) - 2 Nos.
• Voltmeter analog/digital 0-5V - 1 No. • IC Base 28 pin - 1 No.

PROCEDURE

TASK 1: Construct an analog to digital converter circuit using IC0809

1 Refer Fig 1 and wire the analog to digital converter 4 Apply analog input to the input INO, as shown in Table
circuit on a general purpose IC test board using 28 pin 1 of Record sheet.
IC base.
5 Apply logic-1 input to output enable input (OE) using
switch 2.
6 Apply a start pulse using switch SW1 by throwing it
from logic-0 to logic-1 and back to logic-0.
7 Measure and record the digital output levels in the
Record sheet.
8 Repeat steps 4 to 7 for different analog inputs referring
to the Table 1 of O&T sheet.
9 Calculate the theoretical value for each set of recorded
digital output using the formula.
Vth = Vref [D7.2-0 + D6.2-1 +D5.2-2 + D4.2-3 + D3.2-4 +
D2.2-5 + D1.2-6 + D0.2-7]
10 Compare both the actual analog input voltage applied
Vin and the calculated theoretical analog voltage Vth.in.
11 Get the work checked by your instructor.

2 Insert the IC and apply +5V to VCC +Vref and OV to -Vref

to the circuit constructed.
3 Apply a 100 KHZ square wave as clock input at pin
no.10.

214
 Record Sheet for Exercise 1.4.11

1 Table 1

Sl.No. I/p volts Vth Digital O/P

Calculated theoretical analog D7 D6 D5 D4 D3 D2 D1 D0
with respect to digital output

1 5

2 4.5

3 4

4 3.5

5 3

6 2.5

7 2

8 1.5

9 1

10 0.5

Note: If digital output D=Logic 1, then the equivalent analog voltage will be as follows.

D7 = 2.5V

D6 = 1.25V

D5 = 0.625

D4 = 0.3125

D3 = 0.15625

D2 = 0.07812

D1 = 0.03906

D0 = 0.01953

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.4.11 215

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.12

Construct and test Digital to Analog (D/A) converter

Objectives: At the end of this exercise you shall be able to
• assemble and test a digital to analog converter using R-2R ladder network and op-amp
• construct and test a D to A converter using ICDAC0808.

Requirements

Tools/Equipments/Instruments • Resistors, carbon film

1KΩ/¼w - 2 Nos.
• Trainees tool kit - 1 No.
10KΩ/¼w - 15 Nos.
• DC power supply 5V/500 mA - 1 No.
• Capacitors 15PF/50V - 1 No.
• DC power supply 15V/500 mA - 1 No.
• General purpose IC test board - 1 No.
Materials/Components • IC Base 8 pin, 16 pin - 1 No each.
• ICDAC0808 - 1 No. • Solder, flux - as reqd.
• ICmA741 - 1 No. • Connecting wires - as reqd.
• Potentiometer disc type
2.2K/1w - 1 No.
10K/1w - 2 Nos.

PROCEDURE

TASK 1: Construct and test D to A converter using R-2R ladder network

1 Refer Fig 1 and wire only the op-amp circuit using IC741 5 Wire the remaining part of R-2R ladder network on IC
and 8 pin IC base on a general purpose IC test board. test board ensuring four terminal connections D0 to D3
to come on one side of the IC test board.
2 Connect the power supply ±15V to the IC741 referring
to Fig 1. 6 Get the work checked by your instructor.
7 Apply binary logic inputs at D0 to D3 as per Table 1 of
Record sheet and record the measured voltage at the
output of the op-amp.
8 Repeat step 7 for different binary input combinations.
9 Calculate the theoretical Vo by using the formula for
different binary input combinations and record the same
in Table 1 of Record sheet.
Formula for theoretical output V0
V0 =
V = logic-1 input voltage
3 Adjust the output voltage Vo of the op-amp near to zero 10 Get the work checked by your instructor.
using 10K 'pot' by shorting the inverting and non-
inverting input pins of op-amp.
4 Remove the short link after adjusting the op-amp output
to zero volts.

216
TASK 2: Construct and test a digital to analog converter using ICDAC0808

1 Remove the R-2R ladder network wired in step 5 of Task

1 keeping op-amp circuit intact.
2 Replace the feedback resistor of op-amp circuit with
1KW resistor referring to Fig 2.
3 Adjust the output of op-amp to zero Volts by repeating
steps 2, 3 and 4 of Task 1.
4 Wire the remaining part of circuit using ICDAC0808 by
referring to Fig 2.
At this stage, do not make connection between (pin 4)
DAC0808IC and op-amp circuit.
5 Get the work checked by your instructor.
6 Apply 15V to the VCC, -15V to VEE and 2V to Vref pins of
DAC0808.
7 Set the current through pin 14 to 2mA by adjusting the
2.2K Potentiometer.
10 Compare the theoretical and practical results of output
8 Apply different logic input levels at data input pins D0 to voltage.
D7 referring to Table 2 of Record sheet and record the
corresponding analog output Voltage. 11 Get the work checked by your instructor.

9 Calculate the theoretical value of analog output using

formula for each set of digital inputs applied at D0 to D7
and record the same in Table 2.

Record Sheet for Exercise 1.4.12

1 Table 1

Digital I/P Vo Vo
Sl. No. D0 D1 D2 D3 Theoretical Practical

0 0 0 0
1 0 0 0
0 1 0 0
1 1 0 0
0 0 1 0
1 0 1 0
0 1 1 0
1 1 1 0
0 0 0 1

2 Table 2

Sl.No. Digital input Vo Vo

D7 D6 D5 D4 D3 D2 D1 D0 theoretical Practical

0 0 0 0 0 0 0 1
0 0 0 0 0 0 1 1
0 0 0 0 0 1 1 1
0 0 0 0 1 1 1 1
0 0 0 1 1 1 1 1
0 0 1 1 1 1 1 1
0 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1

(Trainee) (Instructor)

IT & ITES : ICTSM - Exercise 1.4.12 217

IT & ITES
ICTSM - Digital Electronics Exercise 1.4.13

Construct and test shift registers

Objectives: At the end of this exercise you shall be able to
• construct and test a shift register using JK-flip flop IC-7476
• construct and test a 4 bit shift register using IC-7495.

Requirements

Tools/Equipments/Instruments Materials/Components
• DC power supply +5V - 1 No. • Solderless circuit bread board - 1 No.
• Logic probe - 1 No. • IC-7476 (JK flip flop) - 1 No.
• Single shot pulser - 1 No. • IC-7495 (4 bit shift register) - 1 No.
• IC-7404 (Hex inverter) - 1 No.
• Switches SPDT - 5 Nos.

PROCEDURE

TASK 1: Construct and test a 4-bit shift left register using IC-7476

1 Refer Fig 1 and wire the circuit of a shift register on a 5 Give one clock pulse at the clock input. Record the
circuit bread board using IC-7476. output logic levels in the Table 1 of record sheet.
2 Get the wired circuit checked by your instructor. 6 Apply logic-0 to serial input. Repeat step 5 and give the
second and third clock pulses. .
3 Apply logic-0 to clear input (Cr). Measure and record the
output logic levels QA, QB, QC and QD in Table 1 of record 7 Apply logic-1 to serial input and repeat step-5.
sheet. 8 Get the recorded readings verified by your instructor.
4 Apply logic-1 to Clear input (Cr). Apply logic-1 to data
input of the circuit.

TASK 2: Construct and test a 4-bit shift register using IC-7495

(a) Parallel in-parallel out (PIPO) 4 Apply logic-1 to mode control input through switch
SW1.
1 Refer Fig 2 and wire the circuit of a 4 bit shift register on
a circuit bread board using IC-7495. 5 Apply 1011 as a parallel input through switches SW2,
SW3, SW4 and SW5. Give clock pulse to clock input
2 Get the wired circuit checked by your instructor. by using single shot pulser. Record the output logic
3 Connect +5V dc supply to IC-7495. levels QA, QB, QC and QD in Table 2 of record sheet.

218
 With mode control input at logic '1', parallel inputs
A=B=C=D=0, results in QA, QB, QC and QD equal to 0000.
During shift-right, parallel inputs are in don't care condition
i.e. not necessary to be kept in 0.
4 Apply logic-0 to mode control. Apply clock pulse to
clock input and serial inputs to circuit as in Table 3 of
record sheet. Record the corresponding output logic
levels.
5 Get the working of the circuit and recorded readings
checked by your instructor.
6 Switch-off the dc supply.
(c) Serial in, parallel-out (shift left)
1 Refer Fig 4 and wire the circuit on circuit bread board.
2 Get it checked by your instructor.
6 Repeat step 4 and 5 for different parallel inputs and
record corresponding output logic levels in Table 2a of 3 Power on the circuit. Observe the outputs at QA, QB, QC
record sheet. and QD i.e.

7 Get the working of the circuit & recorded readings Note that outputs QA to QD will have some
checked by your instructor. random values.
8 Switch-off the DC supply to the circuit.
4 Apply logic-0 at serial input. Apply a clock pulse at
(b) Serial in, parallel out (shift right) clock input using single shot pulser. Record the output
1 Refer Fig 3 and modify the 4 bit shift register circuit logic levels QA, QB, QC and QD in Table 4 of record sheet.
wired in Task 2 to a serial in, parallel out (SIPO) (shift 5 Apply logic-1 to the mode control input and clock
right) shift register. pulses to clock input for different serial inputs as in
2 Get the modified circuit checked by your instructor. Table 4 of record sheet. Record the output logic levels.
6 Get the working of the circuit and recorded readings
checked by your instructor.

3 Power on circuit. Apply logic-1 to mode control input

and also apply a clock pulse to clock input and record
the parallel output logic levels QA, QB, QC and QD
(should be 0000).

IT & ITES : ICTSM - Exercise 1.4.13 219

 Record sheet for Exercise 1.4.13

1) Table 1
4-bit shift left register using 7476 and 7404

Clock Clear Serial Parallel O/P

input input QD QC QB QA
MSB LSB
x 0 x
¯ 1 1
¯ 1 0
¯ 1 0
¯ 1 1

2) Table 2
4-bit shift register using IC-7495

Mode Clock Parallel input Parallel output

control input D C B A QD QC QB QA

1 ¯ 1 0 1 1
1 ¯ 1 0 1

3) Table 3
Serial in, parallel out (shift right)

Mode control Clock input Parallel input Parallel output

QA QB QC QD

1 ¯ 0000
Serial input
0 ¯ 1
0 ¯ 1
0 ¯ 1
0 ¯ 1

4) Tabe 4
Serial in, parallel-out (Shift left)

Mode control Clock input Serial input Parallel output

QA QB QC QD

1 ¯ 0
1 ¯ 1
1 ¯ 0
1 ¯ 1
1 ¯ 1
1 ¯ 0

(Trainee) (Instructor)

220 IT & ITES : ICTSM - Exercise 1.4.13

IT & ITES
ICTSM - Drives, Relays & Sensors Exercise 1.5.01

Identify & Test types of gears, belts & drives

Objectives: At the end of this exercise you shall be able to
• identify different types of gears
• identify different types of belts
• identify differnet types of drives.

Requirements

Materials
• Gears - assorted type
• Belts - assorted type
• Drivers - assorted type

PROCEDURE

TASK 1: Identify types of gears

1 Pick a gear and identify the type and record in Record 2 Record the specifications of the gear.
sheet.
3 Get the work done checked by your instructor.

Involute Splined shafts and hubs are usually used as connectors in many
Splines different types of applications. One of the most common
applications is to connect motors to gear reducers. They may also be
used in transmission.

Involute splines resemble spur gears, but tend to have different

pressure angles

Straight sided Straight sided splines often serve the same function as involute
splines but have “straight sides” teeth instead of involute teeth.

Sprockets Sprockets are used to run chains or belts. They are typically
used in conveyor systems.

TASK 2: Identify types of belts

1 Pick a belt and identify the type and record in record 2 Record the specifications of the belt.
sheet.
3 Get the work done checked by your instructor.
Refer belt types display board or chart for identifying the
given gear type.

221
TASK 3: Identify types of drives

1 Pick a drive and identify the type and record in record 2 Record the specifications of the drive.
sheet.
3 Get the work done checked by your instructor.
Refer drive types display board or chart for identifying
the given gear type.

Record sheet for Exercise 1.5.01

1 Table 1

SI. No. Type of Gear Specification Application

10

2 Table 2

SI. No. Type of Belt Specification Application

3 Table 3

SI. No. Type of Drive Specification Application

222 IT & ITES : ICTSM - Exercise 1.5.01

IT & ITES
ICTSM - Drives, Relays & Sensors Exercise 1.5.02

Identify different types of relays and sensors

Objectives: At the end of this exercise you shall be able to
• identify the type of relay based on its physical appearance
• identify the number and types of contacts
• measure coil resistance
• test the working of a relay and contacts
• identify the types of sensors.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees tool kit - 1 No/batch. • Assorted types of relays
• DC ammeter 0-1A - 1 No/batch. • Assorted types of sensors
• PSU (30V, 5 amps) - 1 No/batch.

PROCEDURE

TASK 1: Identify and test different types of relays

1 Pick a relay and record its label number in Table 1 of 8 Solder wires at relay coil terminals. Connect the wires
Record sheet. in series with a 1A ammeter to DC PSU.
2 Identify the type of relay and record in Record sheet. 9 Switch ON PSU and check if relay is pulled-in. Record
operate current and hold current values.
Refer relay types display board or chart for identifying
the given relay type. If relay does not pull-in consult your instructor.
3 Record the specifications of the relay coil printed/ 10 Check whether the relay contacts have switch ON/
pasted on the relay. Switch OFF depending on the type of contacts. Use
multimeter as ohmmeter to check continuity or use
4 Locate the relay coil terminals. Measure and record
continuity tester made in Unit -3.
coil resistance.
11 Check if there are any observable defects in the contact
5 Identify and record the type (s) and number of contacts
springs or at the contacts. Record defects.
on the relay.
12 Get the work done checked by your instructor.
6 Find the rated operating voltage of the realy and set DC
PSU output voltage. 13 Repeat steps 1 to 11 to test the remaining given relays
and get your work checked by your instructor.
7 Get the recorded informaltion of the realy checked by
your instructor.

TASK 2 : Identify different types of sensors

1 Pick a sensor and record its label number in Table 2 of 3 Record the specifications of the sensor printed/pasted
Record sheet. on the sensor.
2 Identify the type of sensor and record in Record sheet. 4 Get the recorded information of the sensor checked by
your instructor.
Refer sensor types display board or chart for identifying
the given sensor type.

223
 Record sheet for Exercises 1.5.02

224
1 Table - 1
Label Type of Brief Coil Types and number of relay contacts Rated Measured Measured Checked condition
No. relay specifications resistance Contact Number Contact Number Contact Number relay OPERATE HOLD of relay contacts
type of type of type of voltage current current Electrical Physical
contacts contacts contacts condition condition

IT & ITES : ICTSM - Exercise 1.5.02

(Trainee) (Instructor)
2 Table 2

SI. No. Name of Sensor Brief Specification Application

10

11

12

13

14

15

16

17

18

19

20

IT & ITES : ICTSM - Exercise 1.5.02 225

IT & ITES
ICTSM - Drives, Relays & Sensors Exercise 1.5.03

Identify different types microprocessor chips

Objectives: At the end of this exercise you shall be able to
• identify different types of microprocessor chips from the markings on the processor
• know the specifications from the part numbers printed on the processors.

Requirements

Tools/Equipments/Instruments Materials/Components
• Trainees tool kit - 1 No/batch. • Microprocessor chips - different types

PROCEDURE

TASK 1: Identify types of microprocessors

1 Pick a microprocessor chip and identify the type and 2 Note the number of microprocessor and record in O&T
record in O & T sheet. sheet.
Refer gear types display board or chart for identifying 3 Get the work done checked by your instructor.
the given microprocessor type.

226 IT & ITES : ICTSM - Exercise 1.5.03

 Table 1

SI. No. Processor Manufacturer Speed Pin type Socket Voltage CPU Pin Package
Name Clock Count

10

11

12

13

227
 AMD Processor Ordering Part Number (OPN)
Processor are identified by markings known as ordering part number (OPN)
The OPN identifies the processor and its specifications

Processor Core OPN CODE BRAND NAME TECHNOLOGY

Architecture/Brand AXDA AMD AthlonTM XP 0.13 μm
Name: AX AMD AthlonTM XP 0.18 μm
These alpha characters AMSN AMD AthlonTM MP 0.13 μm
define the core AMP/AHX AMD AthlonTM MP 0.18 μm
architecture of the K7/A AMD Athlon 0.18 μm
processor AHM Mobile AMD AthlonTM 4 0.18 μm
AXMS/AXMD/AXDH Mobile AMD AthlonTM XP 0.13 μm
D/DHD/DHM/DHL AMD DuronTM 4 0.18 μm
SDA AMD SempronTM 0.13 μm
SDC Mobile AMD SempronTM 0.13 μm
Model Number : OPN Code Frequency OPN Code Model Number Frequency
This four digit numeric
0500 500 MHz 1400 1400+ 1200(Mobiles)
field defines the speed of
0550 550 MHz 1500 1500+ 1333 MHz
the processor in
0600 600 MHz 1600 1600+ 1400 MHz
megahertz or Model
0650 650 MHz 1700 1700+ 1467 MHz
Number as appropriate
0700 700 MHz 1800 1800+ 1533 MHz
0750 750 MHz 1900 1900+ 1600 MHz
0800 800 MHz 2000 2000+ 1667 MHz
0850 850 MHz 2100 2100+ 1733 MHz
0900 900 MHz 2200 2200+ 1800 MHz
0950 950 MHz 2400 2400+ 2000 MHz
1000 1000 MHz 2600 2600+ 2133 MHz
1100 1100 MHz 2700 2700+ 2167 MHz
x 1133 1133 MHz
1200 1200 MHz
1300 1300 MHz
1333 1333 MHz
1400 1400 MHz

OPN Code Package Type

Package Type :
This single alpha A CPGA
character defines the B OBGA
package type for this D OPGA
device. E UPGA
F OPGA
G UPGA
OPN Code Voltage

Operating Voltage Y 1.10V

(Nominal Core C 1.15V
Voltage) : T 1.120V
This single alpha X 1.125V
character defines the W 1.30V
voltage for this processor J 1.35V
V 1.40V
Q 1.45V
L 1.50V
H 1.55V
U 1.60V
K 1.65V
P 1.70V
M 1.75V
N 1.80V

228 IT & ITES : ICTSM - Exercise 1.5.03

Maximum Die OPN Code Temperature
Temperature :
R 70° C
This single alpha character
V 85° C
defines the maximum die
T 90° C
temperature for this
S 95° C
processor
Q 100° C

OPN Code CACHE SIZE

Level 2 Cache Size :
This single alpha character 1 64 KB
defines the level 2 cache 2 128 KB
size for this processor, in 3 256 KB
addition to 128 KB 4 512 KB
Level 1 cache.

OPN Code CACHE SIZE

Maximum System-Bus
Speed : B 200 MHz
This single alpha character C 266 MHz
defines the maximum D 333 MHz
system-bus speed for this E 400 MHz
processor

AXDA 2400 DKV3C

AXDA Processor Core AMD Athlon XP processor with Quantispeed architecture
Architecture :
2400 Model Num: 2400+ operating at 2.167 GHz
D Package Type : Organic Pin Grid Array (OPGA)
K Operating Voltage 1.65V
V Max Die Temperature 85C
3 Size of L2 Cache: 256 Kbytes
C System-bus : 266 MHz

IT & ITES : ICTSM - Exercise 1.5.03 229

 APPENDIX - C
REFERENCE BOOKS

1 ABC’s OF ELECTRICAL SOLDERING

- LOUIS M DEZETTEL
2 ELECTRICAL & ELECTRONIC WIRING AND ASSEMBLY
- ENGINEERING INDUSTRY TRAINING MANUAL
3 Mc-GRAW HILL ENCYLOPEDIA OF ELECTRONICS AND COMPUTERS
- SYBIL P.PARKAR
4 EXPERIMENTS IN ELECTRONIC FUNDAMENTALS CIRCUITS, DEVICES AND
APPLICATIONS
- DAVID BUCHLA
5 BASIC ELECTRONICS
- GRAB
6 RELAYS AND THEIR APPLICATIONS
- M.C.SHARMA
7 ELECTRICAL TECHNOLOGY
- B.L.THERAJA
8 ELECTRONIC DEVICES AND CIRCUITRY THEORY
- ROBERT BOYLESTAD & LOUIS NASELSKY
9 CIRCUIT THEORY
- TSKVIYER
10 SOLID STATE ELECTRONIC DEVICES
- BEN G.STREETMANN
11 THE ART OF ELECTRONICS
- PAUL HOROWITZ
12 POWER SUPPLIES, SWITCHING REGULATORS INVERTERS AND CONVERTERS
- GOTTIEB
13 ELECTRONIC DEVICES
- STEPHEN R.FLEEMANN
14 STANDARD BOOK FOR ELECTRICAL ENGINEERS
- Mc GRAWHILL
15 BASIC ELECTRONICS A-TEXT-LAB MANUAL
- PAUL B ZABER, ALBERT P MALVINO
16 ELECTRONIC PRINCIPLES
- MALVINO

230 IT & ITES : ICTSM - Appendix for Practicals

 APPENDIX - C
17 OSCILLATOR CIRCUITS
- THOMAS A.ADAMS
18 THE 555 TIMER APPLICATIONS SOURCE BOOK WITH EXPERIMENTS
- HOWARD M.BERLIN
19 TELE COMMUNICATION SYSTEM
- SMALE
20 MODERN TELEVISION PRACTICE
- R.R.GULATI
21 TELEVISION AND AUDIO HAND BOOK
- BENSON & WHITAKER
22 ELECTRICAL ENGINEERING
- S.L.UPPAL
23 ELECTRICAL CIRCUITS
- J.ADMINISTER
24 PRINCIPLE OF INSTRUMENTATION AND MEASUREMENT
- H.D.COOPER
25 ELECTRONIC DEVICES
- CHADDA, KULSHETRE & SINHA
26 ELECTRONIC MEASUREMENT AND INSTRUMENTS
- S.RAMBHADRAN
27 TRANSISTOR CIRCUIT APPROXIMATION
- A.MALVINO
28 FUNDAMENTAL OF MONOCHROME & COLOUR TELEVISION
- R.R.GULATHI
29 ELECTRONICS & BASIC TELEVISION
- BERNAD GROB

IT & ITES : ICTSM - Appendix for Practicals 231

 APPENDIX - D

Standard commercial carbon composition resistor

Selection of Hacksaw blades
values
Materials to be cut Hard Medium Soft materials
Resistance in Ohms _ 10%
+
materials hardness brass, copper,
material aluminium,
1.0 10 100 1K 10K 100K 1M 10M
Sections and sizes Alloy steel Mild steel bronze
High carbon Medium
1.1 11 110 1.1K 11K 110K 1.1M 11M
steel carbon
1.2 12 120 1.2K 12K 120K 1.2M 12M
steel
1.3 13 130 1.3K 13K 130K 1.3M 13M
1.5 15 150 1.5K 15K 150K 1.5M 15M
32 TPI 32 TPI 1.6 16 160 1.6K 16K 160K 1.5M 16M
1.8 18 180 1.8K 18K 180K 1.8M 18M
2.0 20 200 2K 20K 200K 2.0M 20M
Upto 3mm 24 TPI 2.2 22 220 2.2K 22K 220K 2.2M 22M
2.4 24 240 2.4K 24K 240K 2.4M
24 TPI 24 TPI 2.7 27 270 2.7K 27K 270K 2.7M
3.0 30 300 3K 30K 300K 3.0M
3.3 33 330 3.3K 33K 330K 3.3M
3mm - 6mm 3.6 36 360 3.6K 36K 360K 3.6M
3.9 39 390 3.9K 39K 390K 3.9M
24 TPI 24 TPI 18 TPI 4.3 43 430 4.3K 43K 430K 4.3M
4.7 47 470 4.7K 47K 470K 4.7M
5.1 51 510 5.1K 51K 510K 5.1M
6mm - 13mm 5.6 56 560 5.6K 56K 560K 5.6M
6.2 62 620 6.2K 62K 620K 6.2M
18 TPI 14 TPI 14 TPI 6.8 68 680 6.8K 68K 680K 6.8M
7.5 75 750 7.5K 75K 750K 7.5M
8.2 82 820 8.2K 82K 820K 8.2M
13mm - 25 mm 9.1 91 910 9.1K 91K 910K 9.1K

Coding scheme for three colour band resistors Coding scheme for four colour band resistors

THREE COLOUR BAND FOUR COLOUR BAND TOLERANCE VALUE TABLE

NO COLOUR +-- 20%
SILVER +
-- 10%
GOLD +
-- 5%
FIRST COLOUR BAND SECOND COLOUR BAND THIRD COLOUR BAND
COLOUR VALUE TABLE BROWN +
-- 1%
INDICATES INDICATES INDICATES +
RED -- 2%
BLACK 0 ORANGE 3 BLUE 6 WHITE 9
FIRST NUMERIC VALUE OF SECOND NUMERIC OF VALUE MULTIPILER VALUE GREEN +
BROWN 1 YELLOW 4 VIOLET 7 -- 0.5%
THE RESISTANCE THE RESISTANCE GOLD = 0.1 BLUE +
-- 0.25%
RED 2 GREEN 5 GRAY 8
SILVER ==0.01
SILVER VIOLET +
-- 0.1%
FIRST COLOUR BAND SECOND COLOUR BAND THIRD COLOUR BAND FOURTH COLOUR BAND
INDICATES INDICATES INDICATES INDICATES
FIRST NUMERIC VALUE OF SECOND NUMERIC OF NUMBER OF ZERO’S % DEVIATIONS FROM
THE RESISTANCE THE RESISTANCE TO FOLLOW STANDARD VALUE
(TOLERANCE)

COLOUR VALUE TABLE

EXAMPLE GREEN BLUE GOLD BLACK 0 BLUE 6

EXAMPLE STANDARD VALUE = 2 8 000 OHMS OR 28K
BROWN 1 VIOLET 7 RED GRAY ORANGE SILVER
DEVIATION : 10% OF 28000
RED 2 GRAY 8 2 8 000 +
-- 10%
STANDARD VALUE = 5.6 x 0.1 28000 x 10
i.e = 2800 Ω
ORANGE 3 WHITE 9 100
= 5.6 OHMS YELLOW 4 GOLD 0.1 MAX & MIN VALUES : MAX: 28000 + 2800 = 30800Ω OR 30.8K
MIN : 28000 - 2800 = 25200Ω OR 25.2K
GREEN 5 SILVER 0.01

232 IT & ITES : ICTSM - Appendix for Practicals

 APPENDIX - D

Coding scheme for five colour band resistors Typographical/Numerical

coding of resistor values

COLOUR RING - 1 RING - 2 RING - 3 RING - 4 5.RING

Printed Meaning Examples of Corresponding
BLACK 0 0 0 .0 code Printed code Resistance
BROWN 1 1 1 0 1% format values
RED 2 2 2 00 2%
ORANGE 3 3 3 000
YELLOW 4 4 4 0 000
xE x ohms 1E 1 ohms
GREEN 5 5 5 00 000 0.5 % x x ohms 100 100 ohms
BLUE 6 6 6 0 00 000 xW x ohms 56 W 56 ohms
VIOLET 7 7 7 00 00 000 0.1 %
GREY 8 8 8 0 00 00 000
xKy x.y K ohms 4K7 4.7K ohms
WHITE 9 9 9 00 00 00 000 x.K x K ohms 56K 56K ohms
X 10 -- xMy x.y M ohms 6M8 6.8 M ohms
1
GOLD - - -
X 10 --
2
SILVER - - -
xM xM ohms 10M 10M ohms

Note: x and y may be any integer value.

(LE: 6.01)
RED VIOLET YELLOW RED BROWN
2 7 4 00 +
-- 1%

RED-VIOLET-YELLOW-RED-BROWN = 27.4K Ω +
-- 1% Setting OHM Meter range for resistance Measurement
27400 Ω+
-- 1%
27.4K Ω+
-- 1%
Pots maxmimum resistance value Set meter range to

Less than 100 ohms X 1Ω

Between 100 to 1000 ohms X 10 Ω
Between 1K to 10K ohms X 100 Ω
More than 10 K ohms X 1000 Ω

Summary of magnetic quantities and conversions Resistivity of substances at Room Temperature (20°C)

Quantity Formulae SI unit CGS Conversion Substances Resistivity in W· m

unit figure
Metal-Conductors
Flux (f) φ = BA Weber M 1 Wb = 108M
Silver 1.47 x 10-8
mmf (Wb) (Max- Copper 1.72 x 10-8
= ------- well) Gold 2.45 x 10-8
Rm Aluminimum 2.63 x 10-8
f Tungsten 5.51 x 10-8
Flux density B = ---- Wb/M2 Mx/cm2 1Wb Nickel 7.8 x 10-8
(B) A or or 1T = ------ = Alloy-conductors
B = mH Tesla G m2 Manganin 44 x 10-8
(T) (Gauss) Mx Constantan 49 x 10-8
= 104 ------ = 104G Nichrome 100 x 10-8
cm2 Pure Semiconductors
Carbon 3.5 x 10-5
Magneto mmf = Ampere Ampere -----
Germanium 0.60
motive force NI -turn -turn Silicon 2300
(mmf or Fm) At (A.t)
Insulators
Wood 108 - 1011
Magnetizing NI At At
Paper 1010
intensity or H = ----- At/m Oe 1 ----- = 10-2 ----- = Nylon 8 x 1012
Fieldstrength L (Oerst- m cm Lucite 1013
(H) = B/m ed) 1.256 x 102 Oe Glass 1010 - 1014
Rubber 1013 - 1014
Reluctance 1 1/ At 1 At Amber 5 x 1014
(Rm) Rm = ---- Henry -------- 1---- = 108--------- Mica 1011 - 1015
mA Gcm2 H G.cm2 Sulfur 1015
Teflon 1015
Permeability B H G.cm2 Porcelain 1016
(m) m = --- Wb/ Gauss- 1---- = 106 --------- Polystrene 1016
H At-m cm/A m At Quartz (fused) 75 x 1016

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 APPENDIX - D

Recommended r.p.m for H.S.S drills Note:Select the speed nearest to that shown in Table
Diameter Aluminium,brass Annealed Mild Malleable Hard- Copper Alloy Wood
of drill bronze plastics cast iron steel iron cast or tool steel
mm and hard rubber iron steel cast steel
1.5 12217 8554 6111 5500 4889 3667 2445 18334
2.5 8142 5702 4071 3666 3258 2442 1649 12240
3.0 6112 4278 3056 2750 2445 1833 1222 9168
4.0 4888 3420 2444 2198 1954 1465 977 7344
5.0 4075 2852 2037 1833 1630 1222 815 6108
5.5 3490 2444 1745 1575 1396 1047 698 5232
6.5 3055 2139 1527 1375 1222 917 611 4584
7.0 2712 1900 1356 1222 1084 814 542 4077
8.0 2445 1711 1222 1100 978 733 489 3667
10.0 2037 1426 1018 917 815 611 407 3056
11.0 1746 1222 873 786 698 524 349 2619
12.5 1528 1070 764 688 611 458 306 2292
14.0 1357 950 678 611 543 407 271 2040
16.0 1222 856 611 550 489 367 244 1834
17.5 1110 777 555 500 444 333 222 1668
19.0 1018 713 509 458 407 306 204 1528
22.0 876 611 436 392 350 262 175 1310
25.5 764 535 382 344 305 229 153 1146

Commercially available ‘E I’ stamping sizes

a b c d e f g i k1 k2 k3

EI 42 42 28 7 3.5 21 14 28 35 3.5 - 24.5

EI 48 48 52 8 3.5 24 16 32 40 4 - 28
EI 54 54 36 9 3.5 27 18 36 45 4.5 - 31.5
EI 60 60 40 10 3.5 30 20 40 50 5 - 35
EI 66 66 44 11 4.5 33 22 44 55 5.5 - 38.5
EI 78 78 52 13 4.5 39 26 52 65 6.5 - 45.5
EI 84 84 56 14 4.5 42 28 56 70 7 - 49
EI 92 92 62.3 11.3 4.5 51 23 69 82 5 6.5 57.5
EI 106 106 70.5 14.5 5.5 56 29 77 94 6 8.5 64.5
EI 130 130 87.5 17.5 6.8 70 35 95 115 7.5 10 80
EI 150 150 100 20 7.8 80 40 110 135 7.5 12.5 92.5
EI 170 170 117.5 22.5 8 95 45 125 150 10 12.5 107.5
EI 195 195 134.5 25.5 9.5 109 51 144 171 12 13.5 122.5
EI 231 231 166 29 10 137 58 173 204 13.5 15.5 152.5

NOTE: Nominal thickness of stamping 0.35 mm and 0.5 mm.

NOTE: Refer Table in page 200 for a,b,c,d,e,f,g,i,k1,k2,k3

234 IT & ITES : ICTSM - Appendix for Practicals

 APPENDIX - D

NOTE: Commercially available ‘EI’ stamping dimensions

Universal time-constant curves
d
(i) Inductive circuit with direct current
(ii) Capacitive circuit with direct current

C
k2
100%

90%

80%
VALUES AS A PERCENTAGE OF

70% i, VR FOR RISING CURRENT RL CIRCUIT

CHARGING VOLTAGE RL CIRCUIT f

60%
FINAL OR INITIAL VALUE

50%

e
DISCHARGING CURVE RL CIRCUIT

k3
40%

b
i, V R FOR FALLING CURRENT RL CIRCUIT
30% V L FOR FALLING AND RISING CURRENT

20% g

10%

0%
i k1
0.7T 1 2 3 4 5

FOR INDUCTIVE CIRCUIT - τ TIME ( TIME CONSTANTS L ) a

R

FOR CAPACITIVE CIRCUIT - τ TIME ( TIME CONSTANTS RC )

Standard Transformer Bobbin sizes

NOTE: Standard Transformer bobbin size
(Number of turns of wire that can be accomodated per sqcm.)

b h c k l

EI 42/15 14.5 14.8 30.2 5.1 18.6

EI 48/16 16.5 16.8 34.2 6.0 21.6
EI 54/18 18.5 18.8 38.2 6.8 24.2
EI 60/21 20.6 21.0 42.7 7.7 26.7
EI 66/23 22.6 23.0 48.7 8.7 28.6
EI 78/27 26.6 27.5 56.2 10.7 34.6
C

EI 84/29 28.6 29.5 60.2 11.7 37.6

h

EI 84/43 43.5 74.2

EI 92/24 23.6 24.5 75.0 20.2 46.6
EI 92/33 33.5 84.0
EI 106/33 29.6 33.5 88.1 20.6 46.6
EI 106/46 46.5 101.1
l

EI 130/38 35.7 37.7 105.4 25.9 64.5 b

EI 130/48 47.7 115.4
k
EI 150/42 41.7 122.5
EI 150/52 40.7 51.7 132.5 29.8 70.1
EI 150/62 61.7 142.5
EI 170/57 56.7 151.7
EI 170/67 45.7 66.7 161.7 33.7 85.1
EI 170/77 76.7 171.7
EI 195/58 51.7 186.7
EI 195/71 51.7 70.7 199.7 40.2 109.4
EI 195/86 85.7 214.7
EI 231/65 64.7 215.7
EI 231/81 58.7 80.7 232.7 47.5 127.4
EI 231/100 99.7 250.7

NOTE: Refer Table Bobbin dimensions

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 APPENDIX - D

Turns per centimeter for Bobbin size Dielectric constant K of commonly used insulators
(Average values at room temperature)
Wire size S.W.G Turns Wire size S.W.G Turns
in mm per sq. in mm per sq.
cm cm Material K

1.60 16 34 0.274 32 1131 Vacuum (and air) 1

1.40 17 44 0.250 33 1302 Glass 5
1.22 18 60 0.230 34 1550 Mica 5
1.00 19 85 0.212 35 1860 Rubber 3
0.90 20 104 0.190 36 2247 Neoprene 7
0.80 21 132 0.170 37 2820 Bakelite (plastic) 6
0.710 22 172 0.150 38 3565 Polyethylene 2
0.600 23 233 0.132 39 4758 Vinylite 3
0.560 24 279 0.122 40 5487 Teflon 2
0.500 25 333 0.112 41 6742 Paper 3
0.450 26 411 0.100 42 7874 Polyesters 4
0.425 27 493 0.090 43 10198 Polystyrene 2.5
0.375 28 605 0.080 44 12632 Ceramics-Procelain 7
0.345 29 705 0.071 45 16119 Titanium dioxide 14-110
0.315 30 860 0.061 46 22000 Strontium titanate 7500
0.295 31 976 0.050 47 30533

Note: The number of turns given includes the normal

insulation used in winding.

Coding scheme for capacitors with 2 or 3 bands Coding scheme for ceramic capacitors
Fig 5
2nd
SIGNIFICANT
1st
1st BAND 1st & 2nd BAND DIGIT

A WIDE BAND INDICATES

2nd BAND 1st & 2nd BAND ARE OF
SAME COLOUR
3rd BAND 3rd BAND MULTIPLIER
TEMPERATURE
COEFFICIENT
TOLERANCE

A B C D E

NOTE: Capacitance values formed using colour code is

Fig 7 2nd
always in PF (Picofarads) SIGNIFICANT
Example: DIGIT
1st
MULTIPLIER

BROWN
1st 2nd 3rd
BLACK
Band Band Band
C
B D
RED TEMPERATURE TOLERANCE
A E
COEFFICIENT
Brown Black Red
1 0 102

Capacitance = 1000 pf = 1 kpf

COLOUR CODING SCHEME FOR CERAMIC DISK TYPE CAPACITOR

E E
D
D
C
B C
ORANGE
1st 2nd 3rd A
A. TEMPERATURE
COEFFICIENT A
B

Band Band Band B. 1st DIGIT

RED C. 2nd DIGIT

Orange Orange Red D. MULTIPLIER

3 3 102 E. TOLERANCE

Capacitance = 3300 pf = 3K3 pf

E
D

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 APPENDIX - D

Coding scheme for moulded, tubular paper and

Tolerance mica capacitors
Temperature First Second More Less
Colour Coefficient Digit Digit Multiplier than than
10pf 10 pf
(%) (pf) TUBULAR
PAPER
(A) (B) (C) (D) (E)
Ist DIGIT
VOLTAGE
Black 0 0 0 1.0 ±20 ±2 2nd DIGIT RATING
Brown -30 1 1 10 ±1 --- CAPACITANCE
Red -80 2 2 100 ±2 --- VALUE MULTIPLIER

Orange -150 33 3 1000 ±3 --- TOLERANCE

Yellow -220 4 4 10,000 ±4 ---
Green -330 5 5 ---- ±5 ±0.5 5 BAND CODE
Blue -470 6 6 ---- ±6 ---
Violet -750 7 7 ---- ±7 ---
Gray +30 8 8 0.01 ±8 ±0.25
White +120 to 9 9 0.1 ±10 ±1 1st DIGIT 2nd DIGIT MULTIPLIER
NO COLOUR
TOLERANCE
-750 VOLTAGE

Gold -- -- -- 0.7 ±5 -- MICA

MICA
Silver -- -- -- 0.01 ±10 --
VOLTAGE NO COLOUR TOLERANCE 1st DIGIT MULTIPLIER
2nd DIGIT
NOTE: Capacitance values formed using colour code is always
in PF or Picafarads
SOMETIMES A SIX-COLOUR SYSTEM IS USED.
WHEN IT IS, THE THIRD COLOUR REPRESENTS
THE THIRD DIGIT, AND REST OF THE CODE
IS THE SAME.

Proelectron type code for diodes

Colour First Second Multiplier Tole- Voltage
Digit Digit rance Rating Semiconductor Main function
(Volts) material (First letter) (Second letter)

Black 0 0 1 ±20 100 A Germanium A Signal diode

Brown 1 1 10 ±1 200 B Silicon B Varactor diode
Red 2 2 100 ±2 300 C Gallium arsenid E Tunnel diode
Orange 3 3 1000 ±3 400 D Indium G Oscillator diode
Yellow 4 4 10,000 ±4 500 antimonide H Magnetic field diode
Green 5 5 1,00,000 ±5 600 R Materials for K Hall generator
Blue 6 6 1,000,000 ±6 700 photo conductors M Hall generator
Violet 7 7 10,000,000 ±7 800 and hall P Photo diode
generators Q Luminescence diode
Gray 8 8 100,000,000 ±8 900
T Controllable power rectifier
White 9 9 1,000,000,000 ±9 1000 X Multiplier
Gold -- -- 0.1 ±5 2000 Y Rectifier/power diode
Silver -- -- 0.01 ±10 -- Z Z-diode and reference diode
Examples for identifying types of semiconductor diodes
Type Number Semiconductor material
and nature of semiconductor diode

AA143 Germanium - Signal diode

AEY 30A Germanium - Tunnel diode for
industrial/professional applications
AHY 10 Germanium - Magnetic field diode for
industrial/professional applications
BA 157 Silicon - Signal diode
BAT 43 Silicon - Schottky-diode
BY 103 Silicon - Rectifier diode
BB 121A Silicon - Varactor diode
BZX 84/C9V1 Silicon - Z-diode
BPW 50 Silicon - Photo diode
CQY 65 GaAs - LED

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 APPENDIX - D

Summary of important parameters of CE, CC and CB

Key Information On Rectifiers With amplifiers
Capacitor-input Filter
Common Emitter Common
Half-wave Fullwave Bridge emitter follower Base
amplifier amplifier
Number of 1 2 4 +VCC
+V CC
diodes + Ι in Ιe Ιc +
R1 RC E C Ιo
Vout Z in RE B RC Z out
DC output 1.41 Vs(rms) 1.41 Vs(rms) 1.41 Vs(rms) Vin Vin Vin Vout
SL 100 V EE VCC
voltage Vout -- --
R2 RE CE

Diode current IL 0.5 IL 0.5 IL

rating
Input impe (Rin=R1½½R2) ~RB ½½bRE ~ r`e
Peak inverse 2 Vs(peak) 2V*s(peak) Vs(peak) -dance Zin R1½½R 2½½br` e (High)
voltage
Output ~ RC ~ r`e ~ RC
Ripple frequency fin 2fin 2fin impedance (Medium) (Very low) (Medium)
Zout
* Vs(peak) is the voltage across the secondary and the centre-tap.
Voltage RC ~1 RC
Note : In the case of low-voltage rectifiers, as an improvement gain AV ≅- (low)
to the data given in the table above, r`e r`e
- subtract 0.7 V from the DC output voltage of the half-wave (High) (High)
and fullwave rectifiers
- subtract 1.2 to 1.4 V from the DC load voltage of the bridge Current β R in βR B ~ -1
= =
B + βR E
rectifiers. gain Ai
R i n + β r`e R (Low)
High (Medium)
(when
(Rin=R1½½R2)

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 APPENDIX - D

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 APPENDIX - D

International Morse Code Frequency bands

Abbrevations
A ._ N _ . 1 ._ _ _ _ MHz Megahertz 106 Hz
B _ ... O ___ 2 .._ _ _ GHz Gigahertz 109 Hz
C ..
_ _ P . .
__ 3 ..._ _ THz Terahertz 1012 Hz
D _ .. Q __ _. 4 ...._ PHz Petahertz 1015 Hz
E . R ..
_ 5 ..... EHz Exahertz 1018 Hz
F .._. S ... 6 _....
G _ _. T _ 7 _ _... 30 Hz - 300 Hz Extremely low frequencies (ELF)
H .... U .._ 8 _ _ _.. 300 Hz - 3 kHz Voice frequencies (VF)
I .. V ..._ 9 _ _ _ _. 3 kHz - 30 kHz Very low frequencies (VLF)
J ._ _ _ W ._ _ 0 _____ 30 kHz - 300 kHz Low frequencies (LF)
K _._ X _.._ 300 kHz - 3 Mhz Medium frequencies (MF)
L ._.. Y _._ _ 3 Mhz - 30 Mhz High frequencies (HF)
M __ Z _ _.. 30 Mhz - 300 Mhz Very high frequencies (VHF)
300 MHz - 3 GHz Ultrahigh frequencies (UHF)
3 GHz - 30 GHz Super high frequencies (SHF)
30 GHz - 300 GHz Extremely high frequencies(EHF)
. (Period) ...
_ _ _ 300 GHz - 30 THz Infrared
, (comma) ..
__ __ 30 THz - 300 THz Visible light spectrum
? (question mark) (IMI) .. ..
__ 300 THz - 3 PHz Ultraviolet light
/ (fraction bar) .. .
_ _ 3 PHz - 300 PHz X rays
: (colon) ___ ... 300 PHz - 3 EHz Gamma rays
; (semicolon) ...
_ _ _ 3 EHz - 30 EHz Cosmic rays
( (parethesis) . .
_ __
Band Frequency Band Frequency
) (parenthesis) . .
_ __ _
name range, GHz name range, GHz
‘ (apostrophe) .____ .
- (hyphen or dash) _ ....
_ UHF 0.3 - 1.0 K 18.0 - 26.5
$ (dollar sign) ... ..
_ _ L 1.0 - 1.5 Ka 26.5 - 40.0
“ (quotation marks) . ..
_ _ S 1.5 - 3.9 V 40.0 - 80.0
or, . .. .
_ _ C 3.9 - 8.0 N 80.0 - 170.0
X 8.0 - 12.5 A Above 170
Ku 12.5 - 18.0

Basic mathematical conversions and constants

Fundamental Constants

Constant Symbol Value

PI p 3.14285
Velocity of Light C 2.99793 X 108 Meters/Sec
Permeability of space m0 4 x 10-7 Henries/meter
Permittivity of Space e0 8.38062 X 10-34JS
Boltzmann Constant K 1.38062 X 10-23JK

Unit Conversion
Unit Multiplied To get

Centimeter 0.3937 = Inches

Inches 2.540 = Centimeter
Feet 0.3048 = Meter
Metres 3.281 = Feet
Pounds 0.4536 = Kilograms
Kilograms 2.205 = Pounds
Pound 16 = ounces
Ounce 0.0625 = Pound
Horse power 0.746 = Kilowatts
Kilowatts 1.34 = Horse power

The Greek Alphabets

a Alpha r Rho s Sigma

b Beta h Eta t Tau
p Pi w Omega e Epsilon
g Gamma q Theta f Phi
d Delta m mu l Lambda

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 APPENDIX - D

Frequency bands allocation for different types of services

Band Allocation Remarks

30 - 535 KHz Includes maritime communications and Low and medium radio
navigation, aeronautical radio navigation frequencies
535-1605KHz Standard radio broadcast band AM broadcasting
1605 KHz - Includes amateur radio, CB radio, loran Amateur bands 3.5-4.0 MHz
30 MHz Government radio, international and 28 - 29.7 MHz; industrial,
shortwave broadcast, fixed and mobile scientific and medical band
communications, radio navigation, 26.95 - 27.54 MHz; citizen’s
industrial, scientific, and medical radio band class D for voice is
26.965- 27.045 MHz
30 - 50 MHz Government and non-government, fixed Includes police, fire, forestry,
and mobile highway, and railroad services
VHF band starts at 30 MHz
50-54 MHz Amateur 6-m band
54-72 MHz Television broadcast channels 2 and 4 Also fixed and mobile services
72-76 MHz Government and non-government Aeronautical marker
services beacon on 75 MHz
76-88 MHz Television broadcast channels 5 and 6 Also fixed and mobile
services

Band Allocation Remarks

88-108 MHz FM broadcast Also available for facsimile
broadcast; 88-92 MHz
educational FM broadcast
108-122 MHz Aeronautical navigation Localizers, radio range
and airport control
122 - 174 MHz Government and non-government, fixed 144 - 148 MHz amateur band
and mobile, amateur broadcast
174 - 216 MHz Television broadcast channels 7 to 13 Also fixed and mobileservices

216 - 470 MHz Amateur, government and non-govern- Radio altimeter, glide
ment, fixed and mobile, aeronautical path, and meterorological
navigation, citizen’s radio equipment; citizen’s radio
band 462.5 - 465 MHz civil aviation 225 - 400 MHz; UHF
band starts at 300 MHz
470-890 MHz Television broadcast UHF television broadcast
channels 14 to 83
890 - 3000 MHz Aeronautical radio navigation, amateur Radar bands 1300-1600 MHz
broadcast, studio-transmitter relay

3000 - 30,000 MHz Government and non-government, Super-high frequencies (SHF);

amateur, radio navigation satellite communications
30,000 -300,000 MHz Experimental, government, amateur Extra high frequencies (EHF)

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