Power chokes

Power chokes using powder cores are used where inductance needs to be maintained whilst the choke is biased with a DC or low frequency (50-60Hz) AC current.
They are designed to work with lower level high frequency currents, such as the ripple current in a SMPSU output choke or high frequency interference currents.
In general they are not suitable for use with high level, high frequency currents, as in resonant chokes or discontinuous-mode output chokes and pfc chokes, unless these are at relatively low kHz frequencies.

Benefits

These choke ranges are all based on toroidal powder cores, which have a saturation flux density between two to four times higher than ferrite cores, and a distributed air gap which gives a controlled hold-up of inductance with bias current.
Their "soft-saturation" characteristic allows a significant inductance to be maintained in overload conditions, and the toroidal format gives a lower leakage of flux than gapped ferrite or drum core chokes, for improved emc performance.
The high frequency ranges are based on a Sendust core material, which has low magnetostriction, resulting in low acoustic noise.

Almag dc & ac toroidal powder choke ranges

Experience gained from working with customers for over twenty years, to find the best balance between performance and cost, allows us to offer standard ranges of chokes optimised for particular applications, all with well defined inductance and current handling capabilities.

types WK WKP WSS

using sendust cores

High storage ranges

types WH WHP

using Hi-Flux cores

Low cost ranges

types WE WEP WP WPP WSO

on iron powder cores

types WSR WSS

iron powder or sendust