Electrical choke for power factor correction

Abstract

An electrical choke comprises a magnetic amorphous metal core having, in combination, a distributed gap and a discrete gap. The amorphous metal is an iron based, rapidly solidified alloy. The distributed gap configuration is achieved by subjecting the magnetic core to a heat treatment, causing partial crystallization of the amorphous alloy. Such partial volume crystallization reduces the permeability of the magnetic core from several thousands to a value ranging from 200 to 800. The discrete gap is introduced by cutting the core and inserting a spacer. Depending on the width of the gap and the value of the annealed permeability, effective permeabilities in the range of 200 to 40 can be achieved. Advantageously, the reduced permeability magnetic core maintains its initial permeability under DC bias field excitation and exhibits low core loss, making it especially suited for use in power factor correction applications.

Dependencies are inferred from the claim text.