Transistor Amplifier Circuits Unit 7 – RC Coupling
Exercise 1 – DC Operation
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to determine the dc operating
conditions of an RC-coupled amplifier by using measured values. You will verify your results
with a multimeter.
DISCUSSION
- This RC coupling circuit consists of two cascaded common emitter NPN amplifiers (Q1 and
Q2). - The output of the first transistor is connected to the input (base) of the second transistor
through the coupling capacitor C2. - The coupling capacitor blocks the dc collector current of Q1 from entering the base of Q2.
The coupling capacitor prevents dc interaction and shifting of both transistor Q-points. - RC stands for resistance-capacitance.
- Both transistors have the identical voltage divider circuit and the same component values;
therefore, the dc bias for each transistor is essentially the same.