Patent ID: 7385159

Claim:
A converter for the output of an electric arc welder for welding at a gap between an electrode and a workpiece when a trigger switch is activated, said converter having a first input terminal with a positive voltage having a first magnitude and a first amperage range; a second input terminal with a negative voltage having a second magnitude and a second amperage range; an auxiliary positive voltage supply with a positive voltage substantially greater than said first voltage and a positive current drastically less than said first amperage; an auxiliary negative voltage supply with a negative voltage substantially greater than said second voltage and a negative current drastically less than said second amperage; a first switch connecting said first terminal across said gap; a second switch for connecting said second terminal across said gap; a polarity control device for alternately operating said first and second switches to produce an AC welding current across said gap; a third switch for adding said auxiliary positive voltage to said positive voltage; a fourth switch for adding said auxiliary negative voltage to said negative voltage; and, a switch control device activated to selectively enable said third and fourth switches for operation in unison with said first and second switches, respectively.