Choke (electronics)

This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (June 2023) (Learn how and when to remove this message)

In electronics, a choke is an inductor used to block higher-frequency alternating currents (AC) while passing direct current (DC) and lower-frequency ACs in a circuit. A choke usually consists of a coil of insulated wire often wound on a magnetic core, although some consist of a doughnut-shaped ferrite bead strung on a wire. The choke's impedance increases with frequency. Its low electrical resistance passes both AC and DC with little power loss, but its reactance limits the amount of AC passed.

The name comes from blocking—"choking"—high frequencies while passing low frequencies. It is a functional name; the name "choke" is used if an inductor is used for blocking or decoupling higher frequencies, but the component is simply called an "inductor" if used in electronic filters or tuned circuits. Inductors designed for use as chokes are usually distinguished by not having low-loss construction (high Q factor) required in inductors used in tuned circuits and filtering applications.