Patent ID: 7968822

Claim:
An electric arc welding system comprising: a power lead for providing welding current between an advancing welding wire of a welding electrode and a workpiece, said welding current supplied to said power lead being controlled according to a detected short circuit condition and an anticipated metal breaking fuse condition; a short circuit sensor for detecting said short circuit condition, said short circuit sensor having a short circuit output signal when said welding electrode is shorted with said workpiece creating a short circuit; a premonition sensor for anticipating said metal breaking fuse condition, said premonition sensor having a fuse output signal when said short circuit is about to break; a controller having a first input comprising said short circuit output signal and a second input comprising said fuse output signal, said controller having a switch control output for creating a common gate signal upon initial receipt of said short circuit output signal and said fuse output signal to said controller; and at least two parallel power source modules with a common unregulated and unswitchable isolated DC input and an output connected to said power lead, each of said modules controlled in unison with each other in a same way by a same common waveform signal and said same common gate signal to perform a short circuit arc welding process having an arc condition and a short circuit condition in each of a plurality of welding cycles, each of said modules in series with said power lead and comprising: a regulated DC to DC converter having a DC output signal with a waveform controlled by said common waveform signal from said controller, and an output switch receiving said DC output signal, said output switch being opened by said common gate signal to reduce said welding current in said power lead.