Patent ID: 6930279

Claim:
An electric arc welder for performing a given weld process with a selected A.C. pulse current waveform performed between an electrode and a workpiece, said current waveform including a positive segment and a negative segment, with at least one segment including a peak current and background current, said welder comprising: a power source with a controller having a digital processor including a program to calculate the real time power factor of the weld current and weld voltage, said program including an algorithm to calculate the rms weld voltage, the rms weld current and the average power of said power source; a circuit to multiply said rms current by said rms voltage to produce an rms power level; a circuit to divide said average power by said rms power to create a value representing the actual real time power factor of said power source; and, a circuit to adjust said background current to maintain said power factor at a given level.