| 摘要 |
PURPOSE:To obtain stable arc pulses with a 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-phase 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 the circuit 15 is off, the energy accumulated in the reactor 16, etc. is released via a flywheel diode 18, whereby the arc is sustained. The detection signal of a current detector 19 is compared with a reference signal in a comparing amplifier 20, and the circuit 15 is controlled by the compared signal thereof via a driving device 17; therefore, the output current of the circuit is maintained constant. On the other hand, the detection signal of a voltage detector 25 is compared with the reference signal and amplified, and the output thereof is used as a reference signal of the amplifier 20, by which the circuit 15 is controlled via the device 17, and the arc voltage is made constant. |
