| 摘要 |
PURPOSE:To obtain stable arc pulses with simple circuit constitution by dropping the voltage of an AC power source, and converting the same to pulse-like voltage after rectifying and smoothing then supplying the same to a consumable electrode wire via a DC reactor. CONSTITUTION:A 3-pase AC power source 1 is dropped of voltage with a transformer 12 for welding, and this voltage is rectified with a rectifier 13 and is smoothed with a smoothing capacitor 14, after which it is converted to pulse- like voltage with a switching circuit 15. This voltage is supplied to a wire 8 via a DC reactor 16. When a control signal is turned off by a driving device 17, the circuit 15 goes off, and the energy accumulated in the reactor 16, etc. is released via a flywheel diode 18, whereby the arc is sustained. The detection signal Ed of a current detector 19 is compared and amplified with the reference signal added with a base current supply command signal Eb and a pulse current supply command signal Ep in a comparing amplifier 20, and the circuit 15 is controlled by the compared signal V thereof via a device 17, whereby the output current of the circuit 15 is maintained constant. |
