DEVICE FOR SUPPLYING AC SQUARE WAVE WELDING POWER SOURCE FOR ARC WELDING

摘要

PURPOSE:To obtain a welded joint free from welding defects by impressing the high voltage necessary for arc firing or refiring in the period when the potential of an electrode is of a positive pole with respect to an object to be welded, etc., and providing an impressing circuit nearer the output side than switching elements constituting an inverter. CONSTITUTION:This device is equipped with the impressing circuit for impressing the high voltage of the voltage value necessary for arc firing or refiring or above nearer the output side than the inverter switching elements 1 to 4, i.e., just near the output terminal of the device. The influence by the floating impedance by the wiring in the device for supplying the welding power source decreases. Since the retiring voltage is impressed between the consumable electrode and the base metal without a delay in the rising of the voltage with time, the extremely smooth refiring is attained as against the arc breakage. The arc breakage during welding is suppressed down to the level at which the arc breakage cannot be confirmed by naked eyes. The refiring is smoothly executed without receiving the influence by the floating impedance in this way and, therefore, the uniform welded joint free from the welding defects is easily formed.