Patent ID: 6172888
Filing Date: 2001-01-09
Classification: B23K

Abstract:
A transistor or inverter resistance welding power supply apparatus comprising:set value input means for the input of a desired current set value and a desired voltage set value;constant-current control means for allowing a current fed to materials to be welded together to coincide with said current set value;constant-voltage control means for allowing a voltage between a pair of welding electrodes to coincide with said voltage set value;welding current control mode selecting means for selecting either of a first welding current control mode provided by said constant-current control means and a second welding current control mode provided by said constant-voltage control means, said selecting means making a switchover from said first welding current control mode to said second welding current control mode when said interelectrode voltage reaches a predetermined critical voltage value, said selecting means making a switchover from said second welding current control mode to said first welding current control mode when said current fed to said materials to be welded together reaches a predetermined critical current value; andwelding current sequence control means for executing a welding current supply in a welding current control mode selected by said welding current control mode selecting means.