| 摘要 |
The power-transmission device in the disclosed wireless power-transfer system is provided with an oscillator circuit, a power-transmission antenna, a memory, a reception circuit, and a control circuit. The oscillator circuit outputs AC power converted from DC power supplied by a DC power supply. The power-transmission antenna transmits the AC power outputted by the oscillator circuit in order to output said AC power to a power-reception-device load. The memory holds a prescribed value that indicates the voltage requested by the power-reception device. The reception circuit receives the voltage being supplied to the power-reception-device load. The control circuit: uses a first switching element and a second switching element to vary the time at which to set a first output terminal of the oscillator circuit and a second output terminal of the oscillator circuit to the same potential, thereby varying the output time ratio of the AC voltage outputted by the oscillator circuit; varies the frequency of the AC voltage outputted by the oscillator circuit and determines the AC frequency that maximizes the efficiency of the AC power; brings the received voltage to within the range indicated by the abovementioned prescribed value; and outputs, to the load, AC power that maximizes the aforementioned efficiency. |
