What device is used for converting AC into DC?

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.

Rectifiers are typically constructed from diodes, which allow current to flow only in a single direction. In a simple setup called a half wave rectifier, diodes can block the negative part of the AC waveform, producing a pulsating DC output. To obtain a smoother DC signal, a full wave rectifier is used, which converts the negative half of the AC waveform into a positive. Finally, capacitors are included in this setup to filter the output and decrease its ripple, resulting in a more consistent DC signal.