Class B Amplifier 8

Class-B Power Amplifier:- Class B amplifier is a type of power amplifier where the active device (transistor) conducts only for one half cycle of the input signal. That means the conduction angle is 180° for a Class B amplifier Advantages of Class-B Power Amplifier: 1. High efficiency when compared to the Class A configurations. 2. Push-pull mechanism avoids even harmonics. 3. No DC components in the output (in ideal case) Disdvantages of Class-B Power Amplifier: 1. The major disadvantage is the cross-over distortion. 2. Coupling transformers increases the cost and size. 3. It is difficult to find ideal transformers. 4. Transformer coupling causes hum in the output and also affects the low frequency response. 5. Transformer coupling is not practical in case of huge loads. The class B amplifiers are the positive and negative halves of the signals, that are allocated to the different parts of the circuits and the output device switched ON and OFF continuously. The basic class B amplifiers are used in two complementary transistors which are FET and bipolar.