Inductors are also known as reactors or chokes.  Inductance gives them the property of opposing changes in current and the ability to store and release magnetic energy. They find applications in filtering, energy transfer, tuned circuits and impedance matching.

Like transformers they usually consist of a coil and a magnetic core but there is often only be one winding.  In most transformers it is desirable to minimize the energy stored in the core and high permeabilities are beneficial.  However, an inductor needs to store energy and lower permeabilities become necessary.

For this reason, it is usual to gap the core and this also serves to stabilize the inductance.  If the necessary gap is large fringing effects can cause problems.

Where the fringing flux extends into the winding high localized winding losses can occur.  It is then necessary for the single gap to be replaced with 2 or more smaller gaps or to be fully distributed as is achieved with iron powder cores. 

Inevitably inductors have stray capacitance and this may need to be taken into account in some circuits. As the inductor is only inductive below resonance, the self-resonant frequency may be an important design consideration.   

Avon Magnetics have expertise in all inductor types including:

DC chokes

AC chokes

Swinging chokes

Saturable reactors

Flyback inductors

Single winding inductors for SMPS

Coupled inductors for multiple output SMPS

Ignition coils

EMI suppression inductors – differential and common mode