ARC WELDING DEVICE

摘要

PURPOSE:To improve working efficiency and quality by converting once the output voltage regulating signal for a welding machine to a high frequency signal and controlling the output of the welding machine from the outside of DC current for welding without using the control cable to be exclusively used. CONSTITUTION:The voltage change rate of a variable resistor 12 for regulating an output voltage is converted to a signal (a) of a specified frequency f0 by a V-F converting circuit 28. A carrier (b) of a frequency fs is outputted from a carrier oscillating circuit 29 and is modulated to a signal (c) by a modulating circuit 30. The signal (c) is superposed on welding current cables 16, 17 by a transformer 31 and a capacitor 33. The signal (c) is applied to a demodulating circuit 35 by a transformer 34 and a capacitor 33 and is demodulated to a signal (d) which is applied to an F-V converting circuit 36. The frequency change rate is converted to the voltage change rate in the circuit 36 from which the voltage signal proportional to the frequency is drawn and is inputted as the output voltage regulating signal for a DC power source 14, for welding to a firing phase control circuit 6 of a thyristor.