| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device (power supply device for arc welding) that implements stable drive of switching elements of an inverter circuit and an auxiliary circuit while serving a low output request.SOLUTION: On a higher output side of a predetermined output request, a control circuit 20 of a power supply device 11 performs PWM control of adjusting on pulse widths of control pulse signals S1-S4, S5 output to switching elements TR1-TR4, TR5 of an inverter circuit 13 and an auxiliary circuit 14. On a lower output side of the predetermined output request, on the other hand, a changeover is made to PDM control of adjusting on pulse densities of the control pulse signals S1-S4, S5 while keeping the on pulse widths of the control pulse signals S1-S4, S5 at predetermined widths (minimum widths) enough to turn on the switching elements TR1-TR4, TR5. |
