PROJECT REPORT SHEET
PROJECT DESCRIPTION
NAME
STUDENT ID
: BJT Amplifier
: Atul Anuragi
: C61588
1.) Identify and list all material and components required for this project:
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Resistors
Wires
Capacitors
Transistors
2.) Identify and list the tools required to complete this project:
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Breadboard
Clips
Power supply
Power lead
Oscilloscope
Transformer
Multi-meter
3.) Describe steps required to complete this project:
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Construct a common emitter amplifier
Measure the input and output voltages
Using the oscilloscope, trace the input and output wave form
Measure the voltage of Ve,Vb,Vc and Ie using oscilloscope
Compare the input and output wave form.
4.) Briefly describe circuit operation:
Common Base Amplifier
 This is used for high frequency applications because the base separates the input and
output, minimizing oscillations at high frequency. It has a high voltage gain, low input
impedance and high output impedance compared to the common collector.
 We change C1 and C2 because small capacitor makes not work. Output signal is same
as 555 timer circuit but it works as amplifier.
 The second Common Base Amplifier It has two power sources and output is similar to
other common base amplifier. The current gain of this circuit has less than 1 and the
voltage gain is higher than other circuit
Common Emitter Amplifier
 In the range of active operation of the transistor Vb = Ve + 0.6V and at the operating
point the current is determined Ic = Ie. Therefore the required value of base voltage is
Vb = Ie x Re + 0.6V and the voltage divider is R1/R1+R2 = Ie x Re +0.6/ Vbb.
 The collector voltage VC should be about half the supply voltage Vbb when there is
no signal applied.
 The capacitor C1 must be used to keep any DC component from disturbing the
developed biasing which establishes the operating point.
 C3 provides DC blocking
Common Collector Amplifier
 The common collector amplifier is called an emitter follower. The voltage gain of an
emitter follower is just a little less than one since the emitter voltage is constrained at
the diode drop of about 0.6 volts below the base.
 It is a kind of buffer circuit which gives time delay in the circuit
5.) Suggested application(s):
Audio amplifier
6.) Your observations and comments (if any):
7.) After completion, test the functionality of the device against requirements. Describe
in detail the testing process undertaken and record the data/values
Common base Amplifier
Input signal sine wave will change rectangle wave, but it is showing inverse.
Output signal is bigger than input and it is about 3~3.5 times.
Common emitter amplifier
Input signal is 2.82Vp-p sine wave but it will change to rectangle wave
The bottom of output signal is bigger than input and it is about 5.5 times.
Common Collector Amplifier
The input and output wave form is same, but about 0.6V below the base because
of diode drop
Diagnose and rectify faults
Does the device operate correctly after completion?
YES
If no, complete sections below.
1.) Describe in detail the action(s) taken to diagnose the fault:
2.) Describe in details the action(s) taken to rectify the fault:
3.) List the faulty component(s) and/or adjustments required to rectify the fault:
4.) Identify the tools required to diagnose the fault:
5.) Identify all material and components required to rectify the fault:
6.) Identify the tools required to rectify the fault: