Patent ID: 6369350
Filing Date: 2002-04-09
Classification: B23K,H05H

Abstract:
A plasma-arc torch system for use in connection with a workpiece, the torch system comprising:a power source providing an output current; an electrode positioned in a circuit path with the power source, said electrode having the output current flowing therethrough; a tip adjacent the electrode; a current reference circuit providing a current reference signal having a parameter indicative of a desired output current a current regulator circuit providing an error signal having a parameter indicative of a difference between the output current and the desired output current; a rate of change sensor receiving the error signal, said rate of change sensor detecting a rate of change in the error signal and selectively providing a switch control signal having a parameter indicative of the rate of change in the error signal; and a switch circuit responsive to the switch control signal for selectively electrically connecting the tip into the circuit path.