04-01-2013, 04:52 PM
Class-A Power Amplifier.
[attachment=46549]
THEORY:
The power amplifier is said to be Class A amplifier if the Q point and the
input signal are selected such that the output signal is obtained for a full input signal cycle.
For all values of input signal, the transistor remains in the active region and never
enters into cut-off or saturation region. When an a.c signal is applied, the collector voltage
varies sinusoidally hence the collector current also varies sinusoidally.The collector current
flows for 3600 (full cycle) of the input signal. i e the angle of the collector current flow is
3600 .
EC-I Lab Manual EC-261
BAPATLA ENGINEERING COLLEGE (Autonomous):: BAPATLA
PROCEDURE:
1. Connect the circuit as per the circuit diagram.
2. Set Vi =50 mv, using the signal generator.
3. Keeping the input voltage constant, vary the frequency from 10 Hz to 1M Hz in regular
steps and note down the corresponding output voltage.
4. Plot the graph; Gain (dB) vs Frequency(Hz).
[attachment=46549]
THEORY:
The power amplifier is said to be Class A amplifier if the Q point and the
input signal are selected such that the output signal is obtained for a full input signal cycle.
For all values of input signal, the transistor remains in the active region and never
enters into cut-off or saturation region. When an a.c signal is applied, the collector voltage
varies sinusoidally hence the collector current also varies sinusoidally.The collector current
flows for 3600 (full cycle) of the input signal. i e the angle of the collector current flow is
3600 .
EC-I Lab Manual EC-261
BAPATLA ENGINEERING COLLEGE (Autonomous):: BAPATLA
PROCEDURE:
1. Connect the circuit as per the circuit diagram.
2. Set Vi =50 mv, using the signal generator.
3. Keeping the input voltage constant, vary the frequency from 10 Hz to 1M Hz in regular
steps and note down the corresponding output voltage.
4. Plot the graph; Gain (dB) vs Frequency(Hz).