| 摘要 |
PROBLEM TO BE SOLVED: To enable a pseudo arc voltage to be continuously adjusted with a signal from outside by inputting the difference between an inter-outputting- terminal voltage of an arc machining power unit and an arc voltage set value and connecting, between the outputting terminals, an analog element whose conduction quantity varies in proportion to the input. SOLUTION: A DC arc machining power unit 1 having, a drooping characteristic or a constant voltage characteristic is connected to the pseudo arc circuit 9 of an arc loading device through the output terminals Tm1, Tm2 and input terminals Tm5, Tm6, with the inter-terminal voltage Vf detected by a voltage detector 10. In the meantime, by an instrument 14 for setting an arc voltage, a voltage Vr is set equivalent to the arc voltage determined at the time of measuring the characteristic of the power unit 1 and is inputted through an input terminal Tm7. This difference between Vf and Vr, i.e.,ΔV=Vr-Vf, is determined by a comparator 11, and inputted to a transistor 13 through a resistor 12, with the conduction quantity varied in accordance withΔV. Thus, the output current from the power unit 1 is increased/decreased, varying the voltage between the output terminals Tm1, Tm2, and measuring the output characteristic of the power unit 1.
|
