A DC power supply takes electricity from a wall outlet and prepares it for use by electronic devices. Internal circuits convert this AC into direct current, smoothing the flow and stabilizing the. A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a desktop computer. Modern personal computers universally use switched-mode power supplies. Some power supplies have a manual switch for selecting input voltage, while others automatically. That metal box quietly takes the AC power from the wall and turns it into low-voltage DC power your computer parts can actually use. In a personal computer (PC), the power supply. DC power is generated from the conversion of the more commonly available Alternating Current (AC) power, which is supplied by the utility grid or wall outlets.
