Patent ID: 6859128
Filing Date: 2005-02-22
Classification: H01F

Abstract:
1. An output choke for a D.C. arc welder having an inductance comprising a high permeability core having first and second pole pieces and an inductance controlling air gap, said air gap defined by an end surface on said first and second pole pieces, at least a portion of said end surfaces being spaced from one another and facing one another, said end surfaces of said first and second pole pieces having corresponding outer edges being spaced apart substantially the same distance, said end surfaces of said first and second pole pieces having a middle portion positioned between said outer edges, at least a portion of the middle portions of said end surfaces being spaced apart a distance greater than the distance between said outer edges of said end surfaces, said air gap having a configuration which results in said inductance of said choke gradually changing with an output current of the welder without saturation in said air gap thereby eliminating inflection points during operation of said welder.