Patent ID: 6194681
Filing Date: 2001-02-27
Classification: B23K

Abstract:
A power supply apparatus for an arc-utilizing machine, comprising:high-frequency switching means for high-frequency switching a DC signal supplied from a DC signal source into a first high-frequency signal;a transformer having a primary winding and a secondary winding, said first high-frequency signal being supplied to said primary winding, a second high-frequency signal being induced in said secondary winding;a converter for converting said second high-frequency signal into a DC signal;two output terminals receiving said DC signal from said converter, said two output terminals being adapted to be coupled to a non-consumable electrode of the arc-utilizing machine and a workpiece, respectively;a high-frequency ignition voltage generator for providing a third high-frequency signal between said two output terminals;a current detector for detecting current flowing through said non-consumable electrode and workpiece and providing a current-representative signal representing the detected current;an enabling signal generator for providing an enabling signal;high-frequency switching means control means receiving said current-representative signal, said high-frequency switching means control means being responsive to said enabling signal for controlling said high-frequency switching means in such a manner as to maintain said current-representative signal at a predetermined value;high-frequency ignition voltage generator control means for causing said high-frequency ignition voltage generator to start operating when said enabling signal is applied thereto and keeping said high-frequency ignition voltage generator operating until said current-representative signal is generated; anddisabling means for disabling said high-frequency ignition voltage generator when no current-representative signal is generated during a predetermined time period after the generation of said enabling signal.