Patent ID: 8716976

Claim:
A contactless electricity-supplying device comprising: a secondary winding to which an electric power is supplied from a primary winding by an alternating current power supply; an impedance characteristic of Z 1 relative to a frequency has a maximum in a vicinity of a frequency of a fundamental wave component of the alternating current power supply, an impedance characteristic of Z 2 relative to the frequency has the frequency of the fundamental wave component between, a frequency that has a maximum nearest to the frequency of the fundamental wave component, and a frequency that has a minimum nearest to the frequency of the fundamental wave component, wherein Z 1 shows that a coupling coefficient between the primary winding and the secondary winding is a certain value, and that the Z 1 is an impedance of only a primary side when the Z 1 is viewed from an output side of the alternating current power supply, and Z 2 shows that the coupling coefficient between the primary winding and the secondary winding is the certain value, and that the Z 2 is an impedance of only a secondary side when the Z 2 is viewed from a load side connected to the secondary winding.