Patent ID: 7238917
Filing Date: 2007-07-03
Classification: B23K

Abstract:
1. A device to control operation of a power source for an electric arc welder, said power source having a first output terminal connectable to a first welding cable and a second output terminal connectable to a second welding cable, where said cables are to be in a series circuit including a welding gap defined by an electrode and a workpiece, said device comprising: an oscillator driving a first winding for inducing a high frequency voltage into said series circuit, a detector tuned to said high frequency for sensing the level of current in said series circuit at said high frequency and an output circuit to create a start signal when said level exceeds a given value representing a resistance in said gap below a given amount, wherein said first winding is the primary winding of an input transformer and one of said cables is the secondary winding of said input transformer.