A rectifier is a device that converts Alternating Current (AC) which reverses direction, to Direct Current (DC) which flows in only one direction.

• A full-wave rectifier uses both cycles of the AC input to produce a unidirectional output.
• However, the output is not a steady constant value; it varies with time in a series of peaks and valleys (sinusoidal pulses).
• This results in pulsating DC. To get a smooth, steady DC voltage, 'filter' circuits (using capacitors/inductors) are needed.