to set up a common base transistor circuit project pdf

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Abstract:
In electronics, a common base (grounded-base) amplifier is one of the three basic topologies of single-stage bipolar junction transistor (BJT) amplifiers, typically used as a current buffer or voltage amplifier. In this circuit, the emitter terminal of the transistor serves as input, the output manifold and the base is grounded, or "common", hence its name. The field effect transistor analog circuit is the common gate amplifier.




Objective:

Study the input and output characteristics of a transistor in Common Base Configuration.

Components:

No: Name Quantity
1 :Transistor BC 107 1 (One) 
2 :Resistors (1K) 2 (Two) 
3: Breadboard 1 (One)


Equipment:

S.No. Name (Quantity)
1: DC power supply regulated double (0 - 30 V) 1 (Un)
2: Digital ammeters (0 - 200 mA) 2 (Two)
3: Digital Voltmeter (0-20 V) 2 (Two) 
4 :Single strand conductors 2



Budget:

For transistor BC 107:

Maximum Collector Current = 0.1A
Vceo max = 50V

Circuit diagram:





H - Transistor parameter model CB:



Pin Assignment of Transistor:



View from the side of the pins



View from the top of the housing

Operation:

The bipolar junction transistor (BJT) is a three-terminal semiconductor device (emitter, base, manifold). There are two types of BJTs, namely NPN and PNP. It consists of two PN junctions, namely emitter junction and collector junction.

The basic circuit diagram for studying the input characteristics is shown in the circuit diagram. The input is applied between the transmitter and the base, the output is taken between the manifold and the base. the base of the transistor is common to the input and output and hence the name is the common configuration of the base.

Input characteristics are obtained between the input current and the input voltage at constant output voltage. It is represented between VEE and IE in constant VCB in CB configuration.

The output characteristics are obtained between the output voltage and the output current at a constant input current. It is represented between VCB and IC in constant IE in CB configuration.

Process:

Input Features:

Connect the circuit as shown in the circuit diagram.
Keep the output voltage VCB = 0V by varying VCC.
Varying VEE gradually, note the emitter current IE and the emitter-base voltage (VEE).
The size of the pitch is not fixed because of the non-linear curve. Initially vary VEE in steps of 0.1 V. Once the current begins to increase VEE vary in steps of 1V up to 12V.
Repeat the above procedure (step 3) for VCB = 4V.
Output Features:

Connect the circuit as shown in the circuit diagram.
Keep the emitter current IE = 5mA by varying VEE.
Varying VCC gradually in steps from 1V to 12V and record collector current IC and collector-base voltage (VCB).
Repeat the above procedure (step 3) for IE = 10mA.
Repeat the above procedure (step 3) for IE = 10mA.

Observations:

Input characteristics
VEE (Volts) VCB = 0 V VCB = 4 V
VEB (Volts) IE (mA) VEB (Volts) IE (mA)







Output characteristics
VDC (Volts) IE = 0mA IE = 5 V EI = 10 mA
VCB (Volts) IC (mA) VCB (Volts) IC (mA) VCB (Volts) IC





Graphic:


Trace the input characteristics for different VCB values by taking VEE on the X axis and IE on the Y axis with VCB as the constant parameter.
Trace the output characteristics by taking VCB on the X axis and taking IC on the Y axis with IE as a constant parameter.
Graph calculations:

The parameters h will be calculated from the following formulas:

Input characteristics: To obtain input resistance, look for VEE and IE for a constant VCB in one of the input characteristics.
Input impedance = hib = Ri = VEE / IE (VCB = constant)

Inverse voltage gain = hrb = VEB / VCB (IE = constant)

Output characteristics: To obtain output resistance, look for IC and VCB in a constant IE.
Output = hob = 1 / Ro = IC / VCB (IE = constant)

Forward current gain = hfb = IC / IE (VCB = constant)

Inference:

The input resistance is in the order of tens of ohms since the emitter-base junction is forward biased.
The output resistance is in the order of hundreds of kilo-ohms since the Collector-Base junction is reverse polarized.
The higher the value of VCB, the smaller the voltage cut.
The increase in the value of IB causes saturation of the transistor to small voltages.
Precautions:

When performing the experiment, do not exceed the classifications of the transistor. This may cause damage to the transistor.
Connect the voltmeter and ammeter to the correct polarities as shown in the circuit diagram.
Do not turn on the power supply unless you have checked the circuit connections according to the circuit diagram.
Be sure to select the transistor emitter, base, and collector terminals.
Result:

The input and output characteristics of a transistor in common base configuration are studied.

The parameters h for a transistor in CB configuration are:

The input resistance (hib) __________________ Ohms.
The reverse voltage transfer ratio (hrb) __________________.
The Output Input (counter top) __________________ Mhos.
The win