POWER MONITOR FOR CURRENT CONTROLLED RESISTANCE WELDER

摘要

A weld controller (11) utilizing a constant current control employs a stepper program for increasing current boost in predetermined percentage increments following a predetermined stepper current profile (70) to provide compensation for contact tip wear. The weld controller acquires weld power data (91) in the form of current and voltage samples (90) for each step of the stepper program, and computes power from this data during an acquisition run through the stepper program. The weld controller will build a table of values relating weld current and delivered power (70). Subsequent operations of the weld controller will utilize high and low power limit thresholds (77, 78) that track the nominal power profile (70). An event condition will be declared if the weld power is outside the lower or upper threshold.