ELECTRIC ARC WELDER

摘要

An electric arc welder (700) for depositing weld metal along a groove between two edges of a metal workpiece (710, 712) where the welder comprises a first electrode (E1) driven by a first wire feeder (760) toward a point in said groove, a second electrode (E2) driven by a second wire feeder (762) toward the point and a main power source (722) with a first output terminal (724) connected to the first electrode (E1) and a second output terminal (726) connected both to the second electrode (E2) and directly or indirectly to the metal workpiece (710, 712) to create a second electrode path and a workpiece path. The power source (722) includes a high speed switching output stage for creating current with a selected AC waveform between the first and second output terminals (724, 726) where the waveform of the main power source (722) is generated by a waveform generator controlling a pulse width modulator circuit to determine the current operation of the output stage.