Abstract: There is provided an engine driven arc welder adapted for converting a.c. output of welding generator into d.c. output to allow it to undergo switching control by using a switching circuit to detect an output of the switching circuit to control its ON/OFF period by the detected content to control a welding current. The engine driven arc welder has a load limiting function. In this case, AVR is employed in a feedback control loop for generator voltage. The circuit configuration includes a F/V characteristic circuit and an output suppression circuit for comparing a detected voltage of the welding generator with a predetermined reference voltage to deliver, when the detected voltage is lower than the reference voltage, a signal for suppressing a welding output to a constant current control circuit for controlling welding current so that it becomes equal to a fixed value.

Abstract: There is provided an engine driven arc welder adapted for converting a.c. output of welding generator into d.c. output to allow it to undergo switching control by using a switching circuit to detect an output of the switching circuit to control its ON/OFF period by the detected content to control a welding current. This engine driven arc welder further has a reference signal formation circuit for forming a reference signal such that when a detected voltage across welding terminals is higher than a first predetermined value, it has a first reference value.