What is the efficiency of class B push pull amplifier?

Class B push-pull amplifier employs two identical transistors with input signals applied to two stages that are 180° apart from each other. The transistor to be operated in class B mode is kept at the cut off bias and current in this state will be equal to zero. The maximum efficiency of the class B amplifier is 78.5%.

How do you calculate the efficiency of a class B amplifier?

Power Efficiency of Class B Push-Pull Amplifier The current in each transistor is the average value of half sine loop. Here factor 2 is introduced as there are two transistors in push-pull amplifier. The collector efficiency would be the same.

How do you calculate the efficiency of an amplifier?

To determine the efficiency, you need know how to measure the input power of a device. Use the formula P=V*I. You can easily measure the voltage of the amplifier and the current coming into the amplifier using a multimeter or an oscilloscope. The product of voltage and current gives you the input power.

How does a push pull Class B power amplifier work?

The circuit of a push-pull class B power amplifier consists of two identical transistors T 1 and T 2 whose bases are connected to the secondary of the center-tapped input transformer T r1. The emitters are shorted and the collectors are given the V CC supply through the primary of the output transformer T r2.

What is the maximum efficiency of a Class B power amplifier?

Theoretical maximum efficiency of Class B power amplifier is 78.5%. The schematic of a single ended Class B amplifier and input , output waveforms are shown in the figure below. From the above circuit it is clear that the base of the transistor Q1 is not biased and the negative half cycle of the input waveform is missing in the output.

What should be the conduction angle of a Class B amplifier?

That means the conduction angle is 180° for a Class B amplifier. Since the active device is switched off for half the input cycle, the active device dissipates less power and hence the efficiency is improved. Theoretical maximum efficiency of Class B power amplifier is 78.5%.

What is the value of collector current in push pull amplifier?

The output transformer T r3 serves to join the two currents producing an almost undistorted output waveform. The current in each transistor is the average value of half sine loop. Here factor 2 is introduced as there are two transistors in push-pull amplifier. R.M.S. value of collector current = ( I C) m a x / 2