What are capacitors designed for AC use called?

Capacitors designed for AC use are referred to as nonpolarized capacitors. Unlike polarized capacitors, such as electrolytic capacitors, nonpolarized capacitors can operate effectively in both directions. This characteristic makes them particularly suitable for alternating current (AC) applications, where voltage polarity is constantly changing.

Nonpolarized capacitors are utilized in various applications, including audio equipment and coupling and decoupling circuits, where the behavior of the capacitance needs to remain consistent regardless of the direction of current flow. By allowing the current to pass through without concern for polarity, nonpolarized capacitors can provide reliable performance in AC systems.

Other types of capacitors, such as polarized capacitors, are specifically designed to work with direct current (DC) and cannot be used interchangeably in AC applications without risking damage. Electrolytic capacitors, while often used in power supply filtering or similar DC applications, operate under polarity constraints. Film capacitors also have a broader range but can be categorized as nonpolarized depending on their design. Therefore, nonpolarized is the most fitting designation for capacitors used in AC applications.