Question

What is the rectifying process? Explain the half-wave rectifying action of a (p-n) junction diode with the help of a circuit diagram.

Hint:

A half-wave rectifier only allows one half of the AC cycle to pass, meaning it is inefficient and provides a pulsating DC output. Full-wave rectifiers are used when a smoother DC output is required.

Answer 1

Rectifying Process:
The rectifying process refers to the conversion of alternating current (AC) into direct current (DC) by using a diode. A diode only allows current to flow in one direction (forward direction), and thus, when an alternating current is passed through it, only the positive half-cycle or negative half-cycle of the current is allowed to pass. This results in the transformation of AC to a pulsating DC. Half-Wave Rectifier:
In a half-wave rectifier, a single diode is used to allow current to flow during only one half-cycle (positive or negative) of the AC supply. The negative half-cycle of the AC supply is blocked by the diode. Thus, only the positive half of the input signal is passed to the output. In this diagram, the AC supply is connected to the anode of the p-n junction diode. The cathode is connected to the load resistor \( R_L \). During the positive half of the AC cycle, the diode is forward biased and allows current to pass, while during the negative half of the cycle, the diode is reverse biased and blocks current, resulting in zero current flow.
Waveform of a Half-Wave Rectifier:
The output waveform of the half-wave rectifier is a pulsating DC signal that follows the positive half of the input AC signal. The negative half-cycle is blocked. The output voltage is non-zero only during the positive half-cycle of the AC input.