Apparatus and method for welding with AC waveform

摘要

A welder power supply and welding method are provided which welds in a DCEN state, but when a short circuit is detected the current waveform switches to an EP state and the short circuit is cleared while the electrode has a positive polarity.

主权项

1. A welding apparatus, comprising:
a welding power converter which outputs a current which is a DC electrode negative welding waveform having a plurality of current peak portions and background portions where a peak current of each of current peak portions is larger than a highest current level of said background portions, where said welding power converter provides said DC electrode negative welding waveform to an electrode and at least one workpiece to weld said at least one workpiece; a short circuit detection circuit which detects a short circuit event between said electrode and said at least one work piece; and an AC welding module which changes the polarity of said current of said DC electrode negative welding waveform from negative to positive after the detection of said short circuit event, wherein after said current changes to positive polarity, said welding power converter outputs a short clearing current to clear said short circuit event and after said short circuit event is cleared, said AC welding module changes the polarity of said current from positive to negative, and wherein without the detection of said short circuit event said current is maintained as the DC electrode negative welding waveform having a plurality of current peak portions and background portions.