Two-Stage Amplifier: Circuit Analysis and Experimentation, Lab Report

This assignment is a practical exploration of a two-stage amplifier circuit. The assignment involves setting up the circuit, using a function generator and oscilloscope, and taking measurements. The experiment involves analyzing the behavior of the amplifier, including its response to varying input voltages and frequencies. Students are expected to observe the output signal and record the output voltage under different conditions. The goal is to understand the operation of a two-stage amplifier and its characteristics. The assignment also covers the importance of biasing and the effect of the potentiometer on the output signal. The report includes circuit diagrams, experimental procedures, and data analysis. This assignment is designed to provide hands-on experience and a deeper understanding of amplifier circuits.

Lab No: 02
Objective:
To study the two stage amplifier with direct
coupling
Apparatus:
 Transistor amplifier card
 Oscilloscope
 Unitrain box
 Function generator
 voltmeter
Theory:
A transistor must be properly biased in order to operate as an amplifier. The purpose of
dc biasing is to establish a steady level of transistor current and voltage called the DC
operating point or quiescent (Q) point. Biasing a transistor means basically establishing a
certain current and voltage condition. This experiment investigates the operation of a dual-stage
amplifier in which the output of the first stage is directly connected to the input of the second. You will
measure the overall response of a two-stage common emitter amplifier with direct coupling in order to
compare it with the response with capacitive coupling.
Diagram:

Procedure:
 Open the lab soft and then we make connection of the wires according to
the circuit diagram.
 Then we open the function generator and set the data according to the
diagram.
 Then we open the oscilloscope and set data in it according to the given
table.
 We turn potentiometer to the left and measure the output of the amplifier
and then turn the slowly to the right until we see the output signal is cutoff.
 Turn the potentiometer until you see a fully amplified and undistorted
signal.
 Turn the potentiometer to the right until the transistor is goes to the
saturation region and the output is distorted.
Function Generator and oscilloscope:
Undestorted:

Input voltage:
Output voltage:

Now keeping the input amplitude constant at 60 mV, measure the amplitude of
the output voltage at different frequencies
Output voltage: