| 摘要 |
PROBLEM TO BE SOLVED: To enable automatic switching without fluctuations in power supply voltage by the common use of an electric convenience outlet, for both the inverter and the commercial power supply. SOLUTION: This power supply equipment comprises a power outlet 1 for common use of a commercial power supply and an inverter 10, a transfer switch 11 for supplying one of the power supply voltages to the outlet 1, a zero-crossing detection means 12 for detecting the zero crossing time of the commercial power supply voltage; a zero-crossing detection means 13 for the inverter power supply voltage, and a transfer control means 14 for controlling a transfer switch 11, which supplies its power supply voltage when the commercial power supply is not input but the inverter 10 operates thereby supplying its power supply voltage. When the commercial power supply is input but the inverter 10 is not operative, then the former is supplied, and when the inverter 10 is operating and the commercial power supply has been input, the former is supplied from a point in time when both the zero cross detection means 12, 13 have simultaneously detected either one of the points in time of zero cross from either a negative voltage or positive voltage. When the inverter 10 operates in a state in which the commercial power supply has been input, the latter is supplied at the time when both zero-crossing detection means 12, 13 have simultaneously detected the zero crossing time, in a state in which the commercial power is input and the inverter 10 is operative. |
