Abstract: A method for wireless power transmission includes obtaining, via a Q-value circuit, first and second voltages at respective first and second nodes of a resonance circuit. The first and second voltages are effective to determine if foreign matter is present in a space affecting wireless power transmission. The method includes controlling a switching section between the Q-value circuit and the resonance circuit such that at least a part of the electric power transmission process occurs at a different time than when the first and second voltages are obtained.

Abstract: Disclosed herein is a wireless charging system, including: a primary device that includes a power transmitter adapted to transmit power wirelessly; and a secondary device that includes a power receiver adapted to receive power transmitted wirelessly from the power transmitter, wherein the secondary device also includes a sensor adapted to detect any anomaly in the power transmission path between the power transmitter and receiver.

Abstract: In an electrical power transmission system according to the present invention, a frequency generator outputs electrical power of an electrical signal having approximately the same frequency component as a resonant frequency of a resonant element to the resonant element via a driven element. The resonant element is an element having impedance and capacitance and generates a magnetic field by the electrical signal from the frequency generator. A magnetic field coupling circuit is a circuit having the same resonant frequency as the resonant element and becomes coupled by magnetic field resonance with the resonant element. The magnetic field coupling circuit causes magnetic field coupling even with another resonant element and transmits electrical power from the resonant element to the other resonant element. The other resonant element outputs electrical power transmitted through the magnetic field coupling circuit to a rectifier circuit via a driven element.

Abstract: Disclosed herein is a wireless power supplying system, including a power transmission device adapted to transmit power supplied thereto, a repeater device adapted to repeat the transmission power of the power transmission device, and a power reception device adapted to receive the power repeated by said repeater device

Abstract: Disclosed herein is a noncontact electric power feeding apparatus, including: a resonance element for supplying an alternative current electric power in a noncontact style in accordance with a resonance; an alternative current power source portion configured to generate an alternative current electric power to be supplied to said resonance element; and impedance adjusting portion provided between said alternative current power source portion and said resonance element and configured to variably control an impedance in accordance with a coupling coefficient between said noncontact electric power feeding apparatus and an electric power feeding destination of the alternative current electric power.