Constant current SCR power supply method and system for a welding load

摘要

A regulated constant current is supplied to a welding load by an SCR power supply having an SCR rectifier network interposed in series between the welding load and applied input power with the SCR power supply comprising means for generating a first feedback signal proportional to arc current which substantially coincides in time and phase with the arc current; means for generating a second feedback signal proportional to arc current which is substantially nonresponsive to the arc current fundamental ripple frequency, means for weighing the first and second feedback signals in a predetermined proportion to establish an error feedback control signal and means for applying trigger signals to the SCR rectifier network in timed synchronism with the input AC power line as a function of the error feedback control signal.