Question

What is rectification? Explain the working of a full wave rectifier.

Answer 1

Hint: This process of transforming alternating current (ac) into direct current (dc) by allowing the flow of current in one direction only is called rectification. Rectifier is a device which does the same. Rectifiers have many forms. A full wave rectifier is made using either two diodes with a center tapped transformer or four diodes in a bridge configuration.

Complete step by step answer:
Rectifiers can be single phase or multi-phase. Usually for domestic purposes single phase rectifiers are used and for industrial purposes multiphase rectifiers are used. Half wave rectification and full wave rectification are possible for a single phase rectifier.
Full Wave Rectifier converts the whole of the input waveform into pulsating direct current (DC).It converts the both polarities of the input wave form unlike half wave rectifiers which converts only one of the two polarities. This also shows that the average output of the full wave rectifier will be greater than that of half wave rectifier.
Note that the two diodes are connected to a center tapped secondary winding of the transformer. When an alternating current enters the full wave rectifier, in the first half cycle one diode will be in forward biased and the other will be in reverse biased and vice versa for the other half cycle. During the positive half cycle the diode ${D_1}$ is provided with the positive cycle, therefore will be in forward bias. During the negative half cycle the diode ${D_2}$ is provided with the positive cycle, therefore will be in forward bias.

Additional Information:
Full wave rectification is also possible by using 4 diodes in bridge formation.

Here the capacitor is used to smooth the output of the rectifier.

Note: Rectifiers have many applications. Power supply to radios, television etc. requires a steady current DC voltage. There are circuits which do the opposite function They convert DC to alternating current, they are called inverters