Patent ID: 9550248
Date: 2017-01-24
CPC Classifications: B23K

Claim:
1. An electric arc welder comprising: a high speed switching power supply with a controller for creating current pulses at a high frequency through a gap between a workpiece and a welding wire advancing toward the workpiece, wherein each of the high frequency current pulses includes a positive polarity peak current to transfer a droplet of molten metal from the welding wire to the workpiece through the gap; a wave shape generator defining a shape of the high frequency current pulses and a polarity of the high frequency current pulses during a weld cycle, wherein the weld cycle includes current pulses at the high frequency during a low energy portion and a high energy portion; and wherein at least one of the high frequency current pulses only during the low energy portion of the weld cycle includes negative polarity current to generate less heat in the workpiece than the high frequency current pulses during the high energy portion of the weld cycle.