Patent ID: 8723072

Claim:
A plasma cutter comprising: a plasma torch; a plasma cutter power supply device which comprises a plurality of power units capable of supplying electrical current to the plasma torch in parallel; a power supply control device that controls (1) how many among the plurality of power units are to be operated and/or (2) an intensity of output electrical current of each of the power units which is being operated; and a component that simultaneously detects actual values of output currents of the power units, wherein the power supply control device comprises: a component that identifies at least one of (1) a number of faulty power units and (2) a number of operational power units within the plurality of power units by comparing the respective actual values with a command value of an electrical current; a component that selects and turns on selected power units of the operational power units based on (1) the number of faulty power units and (2) the number of operational power units within the plurality of power units; a component that determines, according to cutting conditions, an intensity of electrical current required for operating the plasma torch; and a component which adjusts a respective intensity of the selected power units according to the number of faulty power units and the determined intensity of electrical current required for operating the plasma torch.