A power supply is an electronic device that supplies electric power to an electronic device. The term is most commonly used to describe a component of a personal computer that transforms AC power from the power grid to low-voltage DC power that the computer can use.

A power supply includes a transformer, a rectifier, and a capacitor. The transformer steps up the voltage of the AC power from the power grid, the rectifier converts the AC to DC, and the capacitor smooths out the voltage fluctuations.

A power supply can provide a single voltage or it can provide multiple voltages. …