Patent ID: 8193767

Claim:
A power receiving device, comprising: a power receiving coil having a spiral coil; a rectifier rectifying an alternating voltage generated in the power receiving coil; a secondary battery to which a direct-current voltage rectified in the rectifier is charged; and a magnetic foil arranged in at least one of a position between the spiral coil and the secondary battery, and a position between the spiral coil and the rectifier, wherein the magnetic foil comprises an amorphous alloy thin ribbon or an iron-based Microcrystalline alloy thin ribbon having an average thickness in a range of 5 to 50 μm, wherein the magnetic foil has a Ms·t value of 15 or more and 103.68 or less, where Ms [T] is a saturation flux density of the magnetic foil, t [μm] is a plate thickness of the the magnetic foil, and the Ms·t value [T·μm] is a product of the saturation flux density Ms and the plate thickness t, wherein the power receiving coil has a power receiving rate of 0.25 W/h or more.