Page 51 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

Almost all electronic systems work with amplifiers. We are able to hear the news or other programmes on our
radio, simply because the amplifier in the radio amplifiers the weak signals received by its antenna.
Classification of amplifiers: Linear amplifiers are classified according to their mode of operation, i.e. the way
they operate according to a predetermined set of values. Various amplifier descriptions are based on the following
factors.
1 Based on the transistor configuration

a common emitter (CE) amplifier
b common collector (CC) amplifier
c common Base (CB) amplifier

2 Based on the output
a voltage amplifier
b current amplifier
c power amplifier
3 Based on the input

a small signal amplifier
b large signal amplifier
4 Based on the coupling
a RC coupled amplifier

b transformer coupled amplifier
c impedance coupled amplifier
d direct coupled amplifier
5 Based on the frequency response
a audio frequency (AF) amplifier

b intermediate frequency (IF) amplifier
c radio frequency (RF) amplifier
d VHF and UHF amplifiers

6 Based on the feedback
a current series feedback amplifier
b current parallel feedback amplifier
c voltage series feedback amplifier
d voltage parallel feedback amplifier

7 Based on the biasing conditions
a Class A power amplifier
b Class B power amplifier
c Class AB power amplifier

d Class C power amplifier
Of the above mentioned, serial numbers one and two are explained at this state. Some of the amplifiers dealt in
this book for detailed study the students can refer to any standard books for the remaining portions depending
on their special interest.

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CITS : Power - Electrician & Wireman - Lesson 60-69