What is complementary symmetry power amplifier?

Answer 1

A full and true "quasi complementary symmetry power amplifier" is an audio amplifier whose power output section is typically comprised of 2 of the same NPN output transistors, (generally matched) and 2 of the same PNP or NPN driver transistors, (also generally matched). Driven by dual matching + & - DC voltage power supply voltages. With the exception of the bias control circuit components, each half of the output circuit are exact mirror images of one another. Each half of the circuit amplifies the positive and negative half cycle of the audio signal. The theory is, "it is much more likely to perfectly match the performance of each half cycle of the amplifier by using this circuit design criteria. Only the most esoteric amplifier manufactures used this design in the late 60's and 70's.

Answer 2

class -b power amplifier is used to improve the full power efficiency of class- A amplifier by reducing wasted power in the form of heat . this power amplifier is designed with two transistors in its output stage called as "push pull " amplifier configuration .this amplifier uses two complementary or matching transistors , NPN and PNP with both power transistors receiving same input signal but in opposite phase to each other,i.e one transistor amplifies 180 deg and another amplifies remaining 180 deg of input waveform with the resulting two halves being put back together at the output terminal . The name pudh-pull is due to the pushing and pulling effect of the alternating half cycles by the transistors.

% efficiency is given as :( Pac / Pdc ) x 100