Chokes & Inductors

In electronics a choke is a version of a passive two-terminal electronic component called an inductor which is designed specifically for blocking higher-frequency alternating current (AC) in an electrical circuit, while allowing lower frequency or DC current to pass. Like other inductors, a choke usually consists of a coil of insulated wire often wound on a magnetic core, although some consist of a donut-shaped “bead” of ferrite material strung on a wire. Like other inductors, chokes resist changes to the current passing through them, and so alternating currents of higher frequency, which reverse direction rapidly, are resisted more than currents of lower frequency; the choke’s impedance increases with frequency. Its low electrical resistance allows both AC and DC to pass with little power loss, but it can limit the amount of AC passing through it due to its reactance.

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

Source from Wikimedia