Transistor Amplifier CEΒΆ
The experiment to draw the transistor characteristics can be modified to convert it into a common emitter amplifier. All we need to do is to make a potential divider network to reduce the amplitude of WG to a value less than 80mV. This reduced output is connected to the base through a 1uF capacitor.
Objective Demonstrates the amplifier action of an NPN transistor in the common emitter configuration.
Procedure
- Fix the transistor on bread board and make connection as shown in the figure.
- Set base voltage to the 1 volt and START.
- Set WG amplitude to 80mV.
- Enable A1 and A2
- Use the slider to change base voltage to observe the shift in operating point.
The output is shown below. It can be seen that the input and output signals are 180 degree out of phase.

Discussion
The base current is set the PV2 voltage applied via the
resistor. This sets DC operating point of the circuit.Choose this to get
minimum distortion in the output.