Patent ID: 6870132
Filing Date: 2005-03-22
Classification: B23K

Abstract:
1. A power supply connectable to an AC line voltage source for AC electric arc welding by an AC arc current across a gap between an electrode and a workpiece, said power supply comprising a high capacity transformer for converting said AC line voltage to an AC output voltage, a rectifier for converting said AC output voltage to a DC voltage between a positive terminal and a common terminal at substantially zero volts and a negative terminal and said common terminal, a first switch for connecting said positive terminal to said common terminal across said gap when a gate signal is applied to said first switch, a second switch for connecting said negative terminal to said common terminal across said gap when a gate signal is applied to said second switch, generating means for generating a gate signal of pulses at a given frequency, a first logic gate for directing said gate signal to said first switch for a first time, a secondlogic gate for directing said gate signal to said second switch for a second time, operating means for alternately operating said logic gates to create said AC arc current, a center tapped inductor for reducing the ripple factor caused by said pulses, said inductor having a positive section, a negative section, and a center tap, and a pair of free wheeling diode circuits located on opposite ends of said center tapped inductor.