| 摘要 |
<p>An inverter resistance welding control or power supply apparatus includes a clock generator (62) which generates a clock signal defining a switching cycle of an inverter (16) in a resistance welding machine, a device (60) for preselecting a predetermined reference value corresponding to a desired current peak, a current sensor (50) for detecting primary or secondary current of the welding machine, and an inverter control (CPU 40) for controlling the inverter on a switching cycle-by-cycle basis. Specifically, it turns on the inverter in response to a leading edge of the clock signal, and turns it off either when the current detected signal has reached the reference value or when the clock signal has reached a trailing edge. The control apparatus further includes a magnitude evaluator for measuring a magnitude of the current from the detected signal, which magnitude is expressed in root mean square, arithmetic mean or averaged peak value. The control apparatus further includes a reporter monitor for reporting, based on the measured results, information useful to determine normal or defective operation. There may be further provided a lack-of-secondary current detector for operatively and reliably detecting lack of the secondary current by monitoring the primary current. <IMAGE></p> |
