Consumable electrode type D.C. arc welder

摘要

An invertor controlled D.C. arc welder of consumable electrode type which is arranged to rectify an a.c. power from a commercial power supply, convert it into a high frequency a.c. power by an invertor, rectify it again to obtain a d.c. power output for welding and stabilize the output voltage by feedback control of the invertor based upon the output voltage and provided with means for discriminating shorting and arcing periods of its welding load from the output voltage and additionally controlling the invertor based upon a resultant discrimination signal to raise the output voltage during the early time of the arcing period, thereby preventing defective welding due to insufficient output current. This invention is especially, effective for supplementing such insufficient output current as an aftereffect of insufficient output power during the shortening period in such welder which is provided with means for reducing the output voltage during the shortening period to prevent generation of undesirable spattering.