| 摘要 |
PROBLEM TO BE SOLVED: To provide an AC power supply, capable of reliably matching the phase of a single-phase AC voltage to be outputted by a portable generator, an AC power supply of one's own, with that of an AC voltage to be outputted by an other AC power supply. SOLUTION: Time lags are compared between the zero-cross point of a sine wave form formed, by the PWM control signal controlling an inverter circuit 130 and that in the wave form of the voltage across the output terminals of its portable generator. If both zero-cross points are shifted, the interval of the clock pulses which form the PWM control signal is finely adjusted. This fine adjustment reduces the time lags of both zero-cross points. |
