| 摘要 |
When each weld period starts, a control feeds e.g., a high-level ON signal to switching elements having the associated polarity of an inverter so that the switching elements go on and remain on (step S2). This allows the current to start to flow and rise with a sharp gradient on the primary and secondary sides of a welding transformer. When a current detection signal <I1> from a sensor reaches a preset current value IF for current build-up in that weld period (steps S3 and S4), the control stops the on signal and instead issues a PWM signal to provide a high-frequency (e.g., 10 kHz) switching control of the switching elements (steps S5 to S9). <IMAGE> |
