PULSED ARC WELDING

摘要

A pulsed arc welding system comprises a current pulse generating circuit and a background current generating curcuit including a DC power supply circuit adapted for connection to a load via an electrode wire. A switch causes current pulses generated by the current pulse generating circuit to be applied to the load. The voltage applied by the circuits across the load is detected and the switch controls the pulse repetition rate to maintain a substantially constant predetermined arc voltage across the load. The invention is characterized by determining the lowest arc voltage that occurs in a predetermined time period immediately preceding the onset of each current pulse. This arrangement minimises problems that have occured in the past and avoids errors due to short circuiting.