National Textile University, Faisalabad.
BS. Textile Engineering, Spring 2020.
Course Title: Electrical and electronic systems
Course code: EE-3001
Practical No.
Title of Practical Use of transistor as an amplifier in proteus professional.
Group members
Registration No.
Semester /
Section / Group
Date of Practical May 11, 2020
Date of lab June 1, 2020
report
submission
• Abstract:
This experiment has been performed to study the use of transistor as an amplifier in proteus
professional software. In this experiment, a bipolar junction transistor BJT is made. It acts as
an amplifier by raising the strength of a weak signal. BJT can be connected in three amplifier
configurations such as common-emitter amplifier, common-collecting amplifier and
common-base amplifier are made on the proteus software to understand the use of transistor
as an amplifier. By establishing connections of each circuits, we note down the readings by
changing the resistance.
1
Table of Contents
Abstract:..............................................................................................................................1
Title:....................................................................................................................................3
Introduction:........................................................................................................................3
Objectives:.......................................................................................................................3
Theory:............................................................................................................................3
Apparatus:...........................................................................................................................6
Procedure:...........................................................................................................................6
Common-emitter amplifier:............................................................................................6
Common-collector amplifier:..........................................................................................7
Common-base amplifier:.................................................................................................8
Circuit diagrams on Proteus:...............................................................................................9
Results/ Readings:.............................................................................................................10
Discussion:........................................................................................................................11
Question#01:.................................................................................................................11
Question#02:.................................................................................................................11
Conclusion:.......................................................................................................................11
2
Experiment # 09
• Title:
Use of transistor as an amplifier in proteus professional.
• Introduction:
• Objectives:
1. Use of transistor as an amplifier.
2. Use of three amplifier configurations.
• Theory:
Proteus professional:
The Proteus Design Suite is a proprietary software tool suite used primarily for electronic
design automation. The software is used mainly by electronic design engineers and
technicians to create schematics and electronic prints for manufacturing printed circuit
boards. Proteus is a simulation and design software tool developed by Lab center Electronics
for Electrical and Electronic circuit design. It is a software suite containing schematic,
simulation as well as PCB designing.
1. ISIS is the software used to draw schematics and simulate the circuits in real time. The
simulation allows human access during run time, thus providing real time simulation.
2. ARES is used for PCB designing. It has the feature of viewing output in 3D view of the
designed PCB along with components.
3. The designer can also develop 2D drawings for the product.
Transistor:
A transistor is a device that regulates current or voltage flow and acts as a switch or gate for
electronic signals. Transistors consist of three layers of a semiconductor material, each
capable of carrying a current.
Fig#1: Transistor
Transistor basics:
A transistor is a three terminal device as shown in fig above. Names are following:
3
Base: This is responsible for activating the transistor.
Emitter: This is the negative lead.
Collector: This is positive lead.
A transistor is a device that let you control the flow of current through one channel by
varying the intensity of a much smaller current that’s flowing through a second channel.
Transistor types:
There are two types of transistor:
Bipolar junction transistor (BJT).
Field-effect transistor (FET).
The Bipolar Junction Transistor is a semiconductor device which can be used for switching
or amplification. A Bipolar Junction Transistor (BJT) has three terminals connected to three
doped semiconductor regions. It comes with two types, P-N-P and N-P-N.
Fig#02: Bipolar junction transistor.
Transistor as an amplifier:
A bipolar junction transistor acts as an amplifier by raising the strength of a weak signal. The
DC bias voltage applied to the emitter base junction, makes it remain in forward biased
condition. This forward bias is maintained regardless of the polarity of the signal. The BJT
can be connected in three amplifier configurations i.e. the common-emitter, the common-
base, and the common-collector.
Common-emitter amplifier:
The common emitter amplifier is a three basic single-stage bipolar junction transistor and is
used as a voltage amplifier. The input of this amplifier is taken from the base terminal, the
output is collected from the collector terminal and the emitter terminal is common for both
the terminals. The basic symbol of the common emitter amplifier is shown below:
4
Fig#03: Common-emitter amplifier
Applications of Common Emitter Amplifier
o The common emitter amplifiers are used in the low-frequency voltage amplifiers.
o These amplifiers are used typically in the RF circuits.
o In general, the amplifiers are used in the Low noise amplifiers
Common-base amplifier:
The Common Base Amplifier is another type of bipolar junction transistor, (BJT)
configuration where the base terminal of the transistor is a common terminal to both the input
and output signals, hence its name common base (CB).
For the common base configuration to operate as an amplifier, the input signal is applied to
the emitter terminal and the output is taken from the collector terminal. Thus the emitter
current is also the input current, and the collector current is also the output current, but as the
transistor is a three layer, two pn-junction device, it must be correctly biased for it to work as
a common base amplifier. That is the base-emitter junction is forward-biased.
Fig#04: Common-base amplifier configurations
Applications of Common-base amplifier:
The common base amplifier circuit is used, where the low input impedance is required. The
following are the applications of the common base amplifier circuit.
o It is used in moving coil microphones Preamplifiers.
o It is used in UHF and VHF RF amplifiers.
5
Common-collector amplifier:
The Common Collector Amplifier is another type of bipolar junction transistor, (BJT)
configuration where the input signal is applied to the base terminal and the output signal
taken from the emitter terminal. Thus, the collector terminal is common to both the input and
output circuits. This type of configuration is called Common Collector, (CC) because the
collector terminal is effectively “grounded” or “earthed” through the power supply.
Fig#05: Common-collector amplifier
Applications of Common-collector amplifier:
Some of the applications are listed as follows.
o In the matching circuitry of impedance these circuits are utilized.
o It is well known for its capability of switching technique.
o For the buffering applications these transistors are used.
o In the isolation of the circuits these transistors are used.
• Apparatus:
In proteus professional software, we selected:
Battery
Resistors
Capacitors
Digital oscilloscope
Sine signal generator
Ground terminal
• Procedure:
• Common-emitter amplifier:
Make a circuit of common-emitter amplifier on proteus professional software. For this on
proteus software select battery, capacitors, resistors, digital oscilloscope, sine signal
generator, ground terminal. Establish the connection between them as shown in fig#06.
6
Fig#06: Common-emitter amplifier circuit.
After establishing the connection, run the program. A digital oscilloscope appears, by setting
the time, horizontal and vertical lines on channel 1 and 2, and using a signal generator, set
input voltage Vin such that output voltage Vout is 3V (p-p), keeping the frequency at 50Hz.
Observe the base voltage VS and Vout on the oscilloscope by using both the channels.
Measure and record the reading of Vs, Vout and voltage gain Av.
Vout( P−P)
AV =
Vs (P−P)
Given that re is 78. Calculate and record the voltage gain Av using:
Rc
AV =
ℜ
Change R3 (collector resistance) to 1k, 2k, 3k, and record your readings.
• Common-collector amplifier:
Make a circuit of common-collector amplifier on proteus professional software. For this on
proteus software select battery, capacitors, resistors, digital oscilloscope, sine signal
generator, ground terminal. Establish the connection between them as shown in fig#07.
Fig#07: Common-collector amplifier circuit
In this circuit, input is applied at the base there is coupling capacitor, and the output is at
emitter. Using a signal generator, set input voltage Vin so that Vout is 0.1 V (p-p) undistorted
sine wave, keeping the frequency at 50 Hz. Now observe the base voltage V S and Vout on the
7
oscilloscope by using both the channels. Measure and record the reading of V S, Vout and
voltage gain Av.
Vout( P−P)
AV =
Vs (P−P)
Change R4 (emitter resistance) to 1k, 2k, 3k, and record your readings.
• Common-base amplifier:
Make a circuit of common-base amplifier on proteus professional software. For this on
proteus software select battery, capacitors, resistors, digital oscilloscope, sine signal
generator, ground terminal. Establish the connection between them as shown in fig#08.
Fig#08: Common-base amplifier circuit
In this common-base amplifier, the input ac signal is injected into the emitter-base circuit and
output is taken from the collector-base circuit. The E/B junction is forward-biased by V EE
whereas C/B junction is reverse-biased by VCC. Using a signal generator, input voltage Vin to
100mV and keep its frequency at 50Hz. 2. Observe the collector voltage V S and Vout on the
oscilloscope by using both the channels. Measure and record the reading of Vs, V out and
voltage gain Av.
Vout( P−P)
AV =
Vs (P−P)
Given that re is 29. Calculate and record the voltage gain Av using:
Rc
AV =
ℜ
Change R3 (collector resistance) to 1k, 2k, 3k, and record your readings.
8
• Circuit diagrams on Proteus:
Fig#09: Common-emitter amplifier circuit.
Fig#10: Common-collector amplifier circuit.
9
Fig#11: Common-base amplifier circuit.
• Results/ Readings:
Table#01: Common-emitter amplifier readings:
Vin/mV Collector Measured Measured Measured Calculated
Resistance Vs (p-p) /V Vout(p-p)/V Av Av
R3 / Ω
100 4.7K 50mV=0.05 3V 60 60.25
V
100 1K 50 mV 0.6 V 12 12.82
100 2K 50 mV 1.2 V 24 25.64
100 3K 50 mV 2V 40 38.46
Table#02: Common-collector amplifier readings:
Vin/mV Emitter Measured Measured Measured Av
Resistance R3 / Vs (p-p) /V Vout(p-p)/V
Ω
200 1K 100 mV 100 mV =0.1V 1
200 2K 100 mV 100 mV 1
200 3K 100 mV 100 mV 1
Table#03: Common-base amplifier readings:
Vin/mV Collector Measured Measured Measured Calculated
Resistance Vs (p-p) /V Vout(p-p)/V Av Av
R3 / Ω
100 4.7K 2 mV 300 mV 150 162.0
100 1K 2 mV 60 mV 30 34.0
10
100 2K 2 mV 120 mV 60 68.96
100 3K 2 mV 200 mV 100 103.4
• Discussion:
• Question#01:
Can the same voltage gain be achieved with a common base as with a common emitter
amplifier?
Ans:
Yes. The same voltage gain be achieved with a common base as with a common emitter
amplifier. And sometimes slightly higher voltage gain (especially at high frequencies). But
the current gain will be less; we need a very low impedance signal source to get our gain
from a common-base amplifier.
• Question#02:
Which configuration has the highest voltage gain and why?
Ans:
The common base amplifier configuration produces the highest voltage gain of all the three
bipolar transistor configurations. The ratio of output impedance to input impedance is
greatest in the Common Base configuration, so the ratio of output voltage to input voltage is
greatest.
This type of amplifier configuration is a non-inverting voltage amplifier circuit, in that the
signal voltages Vin and Vout are “in-phase”. This type of transistor arrangement is not very
common due to its unusually high voltage gain characteristics. Its input characteristics
represent that of a forward biased diode while the output characteristics represent that of an
illuminated photo-diode.
Also this type of bipolar transistor configuration has a high ratio of output to input resistance
or more importantly “load” resistance ( RL ) to “input” resistance ( Rin ) giving it a value of
“Resistance Gain”. Then the voltage gain ( Av ) for a common base configuration is therefore
given as:
• Conclusion:
From the above discussed experiment, it is concluded that the common-emitter (CE)
configuration has the emitter as the common terminal, or ground, to an ac signal. CE
amplifiers exhibit medium voltage gain, high power gain and medium current gain. The
common collector amplifier usually referred as emitter follower (EF). Input is applied at the
base there is coupling capacitor, and the output is at emitter. CC amplifiers exhibit low
voltage gain, high current gain and medium power gain. In common-base amplifier, the input
ac signal is injected into the emitter-base circuit and output is taken from the collector-base
11
circuit. The E/B junction is forward-biased by VEE whereas C/B junction is
reverse-biased by VCC. CB amplifiers exhibit high voltage gain, low power
and current gain.
RUBRIC FOR ASSESSING LAB REPORTS
Course & course code: Electrical and Electronics System EE-3001.
Title: use of transistor as an amplifier in proteus professional.
Total Marks Obtained: _____________
Attributes Max. Level 1 Level 2 Level 3 Level 4 Obtained
Marks
Marks Beginning or incomplete Developing Accomplished Exemplary
Abstract/ Several major aspects of the Abstract misses one or Abstract references most The abstract contains
experiment are missing, more major aspects of of the major aspects of reference to all major aspects
Summary 04 student displays a lack of carrying out the the experiment, some of carrying out the experiment
understanding about how to experiment or the minor details are missing and the results, well-written
write an abstract results
Introduction Very little background Some introductory The introduction is nearly Introduction complete and
information provided or information, but still complete, missing some well-written; provides all
04
information is incorrect missing some major minor points necessary background
points principles for the experiment
Experimental Missing several important Written in paragraph Written in paragraph Well-written in paragraph
procedure experimental details or not format, still missing format, important format, all experimental
04 written in paragraph format some important experimental details are details are covered
experimental details covered, some minor
details missing
Results: Figures, graphs, tables contain Most figures, graphs, All figures, graphs, tables All figures, graphs, tables are
errors or are poorly tables OK, some still are correctly drawn, but correctly drawn, are numbered
data, figures, 08 constructed, have missing missing some important some have minor and contain titles/captions.
graphs, titles, captions or numbers, or required features problems or could still be
tables, etc. units missing or incorrect, etc. improved
Discussion Very incomplete or incorrect Some of the results Almost all of the results All-important trends and data
interpretation of trends and have been correctly have been correctly comparisons have been
comparison of data indicating interpreted and interpreted and discussed, interpreted correctly and
08 a lack of understanding of discussed; partial but only minor improvements discussed, a good
results incomplete are needed understanding of results is
understanding of results conveyed
is still evident
Conclusions Conclusions missing or Conclusions regarding All-important conclusions All-important conclusions
missing the important points major points are drawn, have been drawn, could have been clearly made, the
04 but many are misstated, be better stated student shows good
indicating a lack of understanding
understanding
Spelling, Frequent grammar and/or Occasional Less than 3 All grammar/spelling correct
grammar, spelling errors, the writing grammar/spelling grammar/spelling errors, and very well-written
sentence style is rough and immature errors, generally mature, readable style
04
structure readable with some
rough spots in writing
style
Appearance Sections out of order, too Sections in order All sections in order, All sections in order, well-
and much-handwritten copy, contain the minimum formatting generally good formatted, very readable
formatting sloppy formatting allowable amount of but could still be
04
handwritten copy, improved
formatting is rough but
readable
PS: Make necessary conversion as per the number of laboratory
12
13
