DC switched arc torch power supply

a dc power supply, for use with a source of direct current, for supplying direct current to electrodes of a dc arc torch comprising:

• a power supply circuit including an input port coupled to the source of direct current and an output port coupled to the electrodes of the arc torch;
• a control switch and an inductor connected in series along the power supply circuit between the input port and the output port;
• a free-wheeling diode coupled to the power supply circuit such that the diode is reverse biased when the switch is ON, and forward biased when the switch is OFF so to maintain direct current flow across the electrodes and through the inductor;
• and
• a feedback circuit having a current sensor to sense an instantaneous value of current flowing across the electrodes and a control terminal connected to the switch, the feedback circuit providing a control signal at the control terminal to turn the switch ON when the instantaneous value reaches a first level and OFF when the instantaneous value reaches a second level to maintain the instantaneous value substantially between the first and second levels, the first level being less than the second level.