Question

Why is Zener Diode not used in rectifier Circuits?

Answer 1

Zener Diode:

1. Zener Diode is a semiconductor device that allows current flow in either forward or reverse directions.
2. The diode comprises a heavily doped P-N junction to minimize the breakdown voltage.

Rectifier:

1. A rectifier circuit only allows either the positive cycle or a negative cycle of the supplied AC voltage to pass through.
2. Ideally, diodes are used in a normal rectifier circuit.
3. The following circuit snippet shows a rectifier circuit:
4. Ideally, when the diodes are forward-biased, they act as short circuits and when reversed-biased, they act as open circuits.

Diagram

Explanation

1. A rectifier requires a high peak inverse voltage but a Zener Diode only provides a low peak inverse voltage.
2. Therefore, it cannot be used in rectifier circuits.
3. A Zener Diode, also identified as a breakdown diode, is a heavily doped semiconductor device created to work in the reverse direction. When the voltage over the ends of a Zener diode is reversed and the potential approaches the Zener Voltage, the junction cuts down, and the current moves in the reverse direction.

Hence, the above points prove that a Zener Diode cannot be used as a rectifier.