| 摘要 |
PROBLEM TO BE SOLVED: To properly detect dissociation between a drive frequency and a resonant frequency in field resonant type wireless power feeding. SOLUTION: Power is transmitted from a feeding coil L<SB>2</SB>to a receiving coil L<SB>3</SB>by magnetic resonance. A VCO 202 alternately turns ON/OFF switching transistors Q<SB>1</SB>and Q<SB>2</SB>to feed AC current to the feeding coil L<SB>2</SB>, whereby the AC power is fed from the feeding coil L<SB>2</SB>to the receiving coil L<SB>3</SB>. An AC magnetic field generated by AC current I<SB>S</SB>flowing in the feeding coil L<SB>2</SB>causes inductive current I<SB>SS</SB>to flow in a detection coil L<SB>SS</SB>. A phase detection circuit 150 compares a phase of AC voltage generated by the VCO 202 with a phase of the inductive current I<SB>SS</SB>to detect a phase difference with respect to voltage and current phases, and generates a phase difference indicating voltage indicating the magnitude of the phase difference. The reset circuit 102 forcibly reduces the phase difference indicating voltage when the phase difference indicating voltage exceeds a predetermined threshold. COPYRIGHT: (C)2011,JPO&INPIT
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