Current Compensated Choking Coil
They are used to eliminate asymmetric interference at input side of electric devices. There are high size permeability ferrite cores or special magnetic materials with at least 2 symmetrical windings.
Noise suppressing, Power Network, Accumulating, Filtering and Smoothing coils
There are choking coil of ferrous base or special cup cores and coils with open magnetic circuit.
Choking Coils For Switching Sources and DC/DC Converters
MPP, High-Flux, Cool-My cores or ferrite cores with air gap are mostly used for these coils.
Reactors by Costumer Demands
There are e.g. coils for loudspeaker switches and aerials. Coils can be twist as self-bonded (bobbin-less) e.g. for loudspeaker systems or on open magnetic circuit by specific customer wishes.