common base transister circuit project
Here, I am just writing the main body of project for common base transistor circuit project.
introduction
A transistor is a three terminal active device. These terminals are emitter, base, collector. In common base transistor, base is common for input and out put (emitter and collector). Emitter base junction is always biased and collector base junction is reverse biased. In CB configuration, current through emitter is positive and current through collector is negative and current through base is also negative.
With an increasing the reverse collector voltage, the space- charge width at the output junction increases and the effective base width decreases. This phenomenon is known as Early effect. Then there will be less chance for recombination within th ebase region. With increase of charge gradient within the base region, the current of minority carriers injected across the emitter junction, increases. The current amplification factor of CB configuration is given by
Aim
1. To observe and draw the input and output characteristics of a transistor connected in common base configuration.
2. To find current gain () of the given transistor.
Material required
1. A pnp transistor
2. Regulated power supply ( 0 to 30 V, 1A) and a 3 volt battery
3. voltmeter
4. ammeter'
5. 2 high resistance
6. connecting wire
procedure
input characteristics:
1. Connections are made as per the circuit diagram.
2. For plotting the input characteristics, the output voltage VCE is kept constant at 0V and for different values of VBE note down the values of IE.
3. Repeat the above step keeping VCB at 2V, 4V, and 6V. All the reading are tabulated.
4. A graph is drawn between VBE and IE for constant VCB.
output characteristics:
1.connection are made as per the circuit diagram.
2. For plotting the output characteristics, the input IE is kept constant at 10 mA and for different values of VCB, note down the values of IC.
3. repeat the above step for the values of IE at 20 mA, 40 mA and 60 mA. all the reading are tabulated.
Observation:
1- least count of voltmeter Vi = 0.1 volt
2. Range of voltmeter Vi = 0-5 volts
3. Zero error of voltmeter Vi = no error
4. Least count of voltmeter = Vo= 0.1 volt
5. Range of voltmeter = Vo= 0 - 5 volts
6. Zero error of voltmeter = Vo= no error
7. Range of milli-ammeter = 0-50 mA.
8.Zero error in milli-ammeter = no error
now, all input characteristics and output characteristics values are tabulated.
then, we do the calculations
and then, finally, result are written,
1-input, output and transfer chracteristics in the graph
2-current gain
3-The voltage gain
following precautions should be necessary
1- voltage supply should not be greater than the rating of the transistor
2- Meter should be connected properly according to their polarity.
Source of error
1-Transistor may be faulty
2-there may be error in voltmeters
at last we write some Bibilography
books and websites
introduction
A transistor is a three terminal active device. These terminals are emitter, base, collector. In common base transistor, base is common for input and out put (emitter and collector). Emitter base junction is always biased and collector base junction is reverse biased. In CB configuration, current through emitter is positive and current through collector is negative and current through base is also negative.
With an increasing the reverse collector voltage, the space- charge width at the output junction increases and the effective base width decreases. This phenomenon is known as Early effect. Then there will be less chance for recombination within th ebase region. With increase of charge gradient within the base region, the current of minority carriers injected across the emitter junction, increases. The current amplification factor of CB configuration is given by
Aim
1. To observe and draw the input and output characteristics of a transistor connected in common base configuration.
2. To find current gain () of the given transistor.
Material required
1. A pnp transistor
2. Regulated power supply ( 0 to 30 V, 1A) and a 3 volt battery
3. voltmeter
4. ammeter'
5. 2 high resistance
6. connecting wire
procedure
input characteristics:
1. Connections are made as per the circuit diagram.
2. For plotting the input characteristics, the output voltage VCE is kept constant at 0V and for different values of VBE note down the values of IE.
3. Repeat the above step keeping VCB at 2V, 4V, and 6V. All the reading are tabulated.
4. A graph is drawn between VBE and IE for constant VCB.
output characteristics:
1.connection are made as per the circuit diagram.
2. For plotting the output characteristics, the input IE is kept constant at 10 mA and for different values of VCB, note down the values of IC.
3. repeat the above step for the values of IE at 20 mA, 40 mA and 60 mA. all the reading are tabulated.
Observation:
1- least count of voltmeter Vi = 0.1 volt
2. Range of voltmeter Vi = 0-5 volts
3. Zero error of voltmeter Vi = no error
4. Least count of voltmeter = Vo= 0.1 volt
5. Range of voltmeter = Vo= 0 - 5 volts
6. Zero error of voltmeter = Vo= no error
7. Range of milli-ammeter = 0-50 mA.
8.Zero error in milli-ammeter = no error
now, all input characteristics and output characteristics values are tabulated.
then, we do the calculations
and then, finally, result are written,
1-input, output and transfer chracteristics in the graph
2-current gain
3-The voltage gain
following precautions should be necessary
1- voltage supply should not be greater than the rating of the transistor
2- Meter should be connected properly according to their polarity.
Source of error
1-Transistor may be faulty
2-there may be error in voltmeters
at last we write some Bibilography
books and websites