What device is used to convert Alternating Current (AC) to Direct Current (DC)?

The device that is used to convert Alternating Current (AC) to Direct Current (DC) is called a rectifier. Rectifiers are essential in a variety of electronic applications, particularly in situations where devices or circuits require a stable DC voltage to operate effectively.

AC is an electric current that reverses its direction periodically, whereas DC flows in a single direction. The rectification process involves using components such as diodes, which allow current to flow in only one direction, effectively blocking the reverse flow and resulting in a unidirectional output. This process smooths the AC input so that it can be used in devices that require DC for operation, such as in battery charging, power supplies, and certain types of electronic equipment.

The other options include devices that serve different functions: a transformer changes voltage levels of AC but does not convert AC to DC; a converter is a more general term that can refer to devices that change electrical signals but does not specifically denote the function of converting AC to DC; and an inverter changes DC back to AC. Hence, the rectifier is specifically designed for the conversion of accumulated AC into usable DC power.