Patent ID: 6570130
Filing Date: 2003-05-27
Classification: B23K

Abstract:
A device for terminating operation of the power source of an electric arc welder for passing a current between an electrode and work piece from a first stud connected to said electrode by a first cable and a second stud connected to said work piece by a second cable to perform a welding process, said welder further having a first voltage sense lead connected to said electrode and a second voltage sense lead connected to said work piece, said device comprising: an executive program to implement a test sequence, said sequence involving program routine to create a first signal representing a theoretical voltage value for a given time in said welding process, a sense circuit for generating a second signal representing the voltage at said first and second sense leads at said given time, a calculation program routine to calculate a real time mathematical relationship of said first and second signals, a threshold circuit to set a threshold value of said mathematical relationship, and a decision circuit for creating a welder terminating fault signal when said mathematical relationship is equal to or less than said threshold value.