Scribd
Upload
97 views7 pages

Ecd Lab Report 2

This document describes an electrical engineering lab experiment on common emitter amplifier configurations. The objectives are to examine the behavior of BJTs and MOSFETs as switches and amplifiers. The lab will test biasing schemes and an NMOS inverter. Equipment includes an oscilloscope, function generator, transistors, resistors, and capacitors. The document explains biasing amplifier circuits, shows a common emitter amplifier circuit diagram, and outlines procedures to give an input signal and observe the output waveform. Students will simulate the circuit in Proteus and draw conclusions about resistor biasing and the transistor operating as an amplifier.

Uploaded by

Saqib Ali
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
97 views7 pages

Ecd Lab Report 2

This document describes an electrical engineering lab experiment on common emitter amplifier configurations. The objectives are to examine the behavior of BJTs and MOSFETs as switches and amplifiers. The lab will test biasing schemes and an NMOS inverter. Equipment includes an oscilloscope, function generator, transistors, resistors, and capacitors. The document explains biasing amplifier circuits, shows a common emitter amplifier circuit diagram, and outlines procedures to give an input signal and observe the output waveform. Students will simulate the circuit in Proteus and draw conclusions about resistor biasing and the transistor operating as an amplifier.

Uploaded by

Saqib Ali
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 7

Air University, Islamabad

Department of Electrical Engineering


Electric Circuit Design Lab

Name: Saqib Ali 180535


Syed Ahmad Hassan 180571 A
Muhammad Uzair Ali 180511
/

LAB #02
COMMON EMITTER CONFIGURATION
OBJECTIVES
 To find the behavior of BJT as a switch.
 For a MOSFET to act as an amplifier, a proper DC bias point is required. Therefore,
number of biasing scheme have been represented and we are checking two of the
schemes.
 Checking the behavior of NMOS as an inverter.

Equipment:
1) Oscilloscope

2) Function Generator

3) Transistor

4) Resistors

5) Capacitors

6) Digital Millimeter

ABOUT THE EXPERIMENT


All types of Transistor Amplifiers operate using AC signal inputs which alternate between a positive
value and a negative value so some way of “presetting” the amplifier circuit to operate between these two
maximum or peak values is required. This is achieved using a process known as Biasing. Biasing is very
important in amplifier design as it establishes the correct operating point of the transistor amplifier ready
to receive signals, thereby reducing any distortion to the output signal. Static or DC load line can be
drawn onto the output characteristics curves to show all the possible operating points of the transistor
from fully “ON” to fully “OFF”, and to which the quiescent operating point or Q-point of the amplifier
can be found. The aim of any small signal amplifier is to amplify all of the input signal with the minimum
amount of distortion possible to the output signal, in other words, the output signal must be an exact
reproduction of the input signal but only bigger (amplified). To obtain low distortion when used as an
amplifier, the operating quiescent point needs to be correctly selected. This is in fact the DC operating
point of the amplifier and its position may be established at any point along the load line by a suitable
biasing arrangement. The best possible position for this Q-point is as close to the center position of the
load line as reasonably possible, thereby producing a Class A type amplifier operation, i.e. Vce= 1/2Vcc.
Consider the Common Emitter Amplifier circuit shown below

PROCEURE
 We Connect the circuit as given in the manual.
 We Give an input of 40mVp-p (f = 10 kHz) to the amplifier.
 Then Observe the output at Oscilloscope.
 And Draw the input and output waveforms.
 Following are the values, we will use these to perform our task.

Where,

R1 = 20 kΩ C1 = 0.1 μF Vbb = 12V

R2 = 36 kΩ C2 = 0.1 μF Vin = 40 mVp-p (10 kHz)

RC = 2 kΩ CE = 22 μF

RE = 1.5 kΩ RL = 1 kΩ

PROTEUS SIMULATIONS BY 180535(Saqib Ali)

Output:
PROTEUS SIMULATIONS BY 180571(Syed Ahmad Hassan)

Output:
PROTEUS SIMULATIONS BY 180511(Mohammad Uzair Ali)

Output:
CONCLUSION:
In this lab Common Emitter Amplifier circuit has a resistor in its Collector circuit. The current
flowing through this resistor produces the voltage output of the amplifier. The value of this
resistor is chosen so that at the amplifiers quiescent operating point, Q-point this output voltage
lie half way along the transistors load line.

The Base of the transistor used in a common emitter amplifier is biased using two resistors as a
potential divider network. This type of biasing arrangement is used commonly in the design of
bipolar transistor amplifier circuits and greatly reduces the effects of varying Beta, by holding
the Base bias at a constant steady voltage

You might also like