| 摘要 |
PURPOSE:To make the continuous changing of the output of a power source from constant voltage characteristics to constant current characteristics possible in an electric power source device for arc welding by driving a DC-AC converter with the deviation values between the detected current and voltage values of high frequency outputs and respective reference values. CONSTITUTION:The DC output of the 1st rectifying part 1 for an AC power source of a commercial frequency is converted to high frequency pulsation, and is regulated to prescribed voltage with a high frequency voltage transformer 3; thereafter, the high frequency pulsation is smoothed in the 2nd rectifying part. The output current and voltage thereof are detected with detectors 6, 7, and the values thereof and reference values 8 are inputted to an error amplifier 9 which emits the output signals corresponding to the respective deviations. A pulse width changing signal and the output of a master oscillator 10 are inputted to a pulse width converter 11, by which pulse width is changed. The driving element of a DC-AC converter 2 is driven by a driver circuit 12, and the converter 2 converts the DC to AC immediately, whereby the power source output is changed continuously from roughly constant voltage characteristics to constant current characteristics. |
