| 摘要 |
PROBLEM TO BE SOLVED: To drive an electric motor of three phase 200 V using single phase 100 V power supply by transforming single phase 100 V AC power supply to single phase 200 V AC power supply, and generating AC voltage of three phase 200 V from DC power supply outputted by full-wave rectification of the single phase 200 V AC voltage. SOLUTION: Single phase AC power supply outputted from single phase AC power supply 20 of 100 V is full-wave-rectified in a full-wave rectifying circuit 22 after the single phase AC power supply is set as double voltage through a step-up transformer 21. And then, it is supplied to an inverter 23. In a control circuit 38, gate signals G11 and G16, gate signals G13 and G12, and gate signals G15 and G14 are turned on alternately, and thereby, transistors Q11 and Q16, transistors Q13 and Q12, and transistors Q15 and Q14 are conducted alternately. At this time, cycles for turning on the gate signals G11 and G16, the gate signals G13 and G12, and the gate signals G!5 and G15 are set variable so as to vary an AC frequency of three phase 200 V supplied to the electric motor 24. |
