| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that there is a concern for occurrence of electric shock where power leaks unintendedly from electric paths L1, L2.SOLUTION: A first coil 22 is connected with electric paths L1, L2 via a resonance circuit 20. Power of an external power supply 10 is supplied in noncontact to a vehicle, when the first coil 22 is coupled magnetically with a second coil 24 mounted on the vehicle. Power is supplied to the first coil 22 by outputting a rectangular signal having a frequency (ω/2&pgr;) by means of an inverter 14. A multiplier 34 multiplies a reference signal Sref having a frequency (ω/2&pgr;) by the difference of currents on the electric paths L1, L2 as a difference signal &Dgr;I. A multiplication signal &Dgr;Im thus generated is subjected to low-pass filtering by means of a CPU 44, and a DC component corresponding to an amplitude of the difference of AC currents on the electric paths L1, L2 is extracted. Presence or absence of electric leakage is diagnosed depending on this value. |
