Importance

Loading Importance Indicators...

Abstract

A circuit for providing D.C. current from a power source having a current regulating input to a plasma system including an electrode and a nozzle with a plasma arc opening exposing the electrode to a juxtapositioned workpiece, which circuit has a first circuit branch for creating a pilot arc across the electrode and nozzle, a second circuit branch for creating an operative plasma arc across the electrode and the workpiece, a current sensor in the second circuit branch for sensing the workpiece current in the second circuit branch, a switch for opening the first circuit branch when the sensed workpiece current exceeds a preselected current to transfer the pilot arc to the operative plasma arc, a system for regulating the current in the first circuit branch until the arc transfer and a circuit for increasing the pilot current supplied from said power source to first circuit branch when sensed workpiece current exceeds a low threshold value.

Loading the Abstract Image...

First Claim