Question

With the help of a circuit diagram, explain the working of a p-n junction diode as a full-wave rectifier. Draw its input and output waveforms.

Hint:

A full-wave rectifier produces an output that is smoother and more consistent than half-wave rectification by using both positive and negative cycles of the input signal.

Answer 1

A full-wave rectifier uses two diodes arranged in a bridge configuration. The AC input is applied to the transformer, and the diodes rectify the current to produce a pulsating DC output. Working: 1. During the positive half-cycle of the input AC voltage, the current flows through the diode D1, and diode D2 is reverse biased and does not conduct. Therefore, current flows through the load resistor \( R_L \) in one direction. 2. During the negative half-cycle, diode D1 is reverse biased and does not conduct, but diode D2 becomes forward biased and allows current to flow through the load resistor in the same direction. This results in a unidirectional output current. \[ \text{Input waveform} \quad \text{and} \quad \text{Output waveform} \] \includegraphics[width=0.5\linewidth]{ph28.c.png}
The input AC voltage alternates in both positive and negative cycles, while the output remains in one direction, providing a pulsating DC.