Transistor Amplifier Circuits Unit 9 – Direct Coupling
UNIT 9 – DIRECT COUPLING
UNIT OBJECTIVE
At the completion of this unit, you will be able to demonstrate the operation of a direct-coupled,
two-stage amplifier by using measured circuit conditions.
UNIT FUNDAMENTALS
When the output of the first-stage amplifier (Q1) is directly connected to the input of the second-
stage amplifier (Q2), the amplifiers are direct coupled.
The frequency response at low frequencies is very good for direct-coupled amplifiers. The dc
conditions of each amplifier stage are not isolated. A direct-coupled amplifier is temperature
sensitive and requires stabilizing circuits to minimize drifting of the dc bias.
NEW TERMS AND WORDS
None
EQUIPMENT REQUIRED
F.A.C.E.T. base unit
Multimeter
Oscilloscope, dual trace
Generator, sine wave
TRANSISTOR AMPLIFIER CIRCUITS circuit board