An inductor, also known as a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. It is a coil of wire that creates a magnetic field when an electric current flows through it. Inductors are primarily used in electrical power and electronic devices for various purposes, including:
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Opposing sudden changes in current: Inductors oppose sudden changes in current and slow down the rate of change of current.
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Blocking or impeding changes in current: An inductor placed in series with a conductor, such as a wire or circuit board trace, blocks or impedes changes in current and functions as a low pass filter.
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Storing energy: Inductors store energy in the form of magnetic energy when electricity is applied to it.
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Filtering ripple current: Inductors in power converters serve to filter the "ripple" current at the output. High inductance values result in lower ripple current.
Inductors are also used in electronic filters to separate signals of different frequencies, and in combination with capacitors to make tuned circuits, used to tune radio and TV receivers. The inductance of a circuit depends on the geometry of the current path as well as the magnetic permeability of nearby materials.
