Abstract: A coil device and a wireless power transmission device which can detect the happened open fault or short fault reliably in any one of the plurality of capacitor elements constituting the capacitor circuit. Coil device includes coil for power transmission, capacitor circuit connected to coil for power transmission and having a plurality of capacitor elements, conductive metal portion which is disposed close to coil for power transmission, and measuring portion for measuring a voltage or a current generated in metal portion.

Abstract: A coil unit, a wireless power feeding device, a wireless power receiving device, and a wireless power transmission device are provided that are capable of reducing high voltage induced on the metal part. A coil unit Lu1 includes a power transmission coil L1, a first reactance circuit X10 that is connected to one end portion of the winding of the power transmission coil L1 and forms a resonant circuit together with the power transmission coil L1, a metal part SD disposed on the same side as the back side of the power transmission coil L1, and a first adjustment capacitor C10 connected between the other end portion of the winding of the power transmission coil L1 and the metal part SD.

Abstract: To provide a wireless power receiving device, and a wireless power transmission device capable of improving the reliability of a protection circuit while preventing breakage of a circuit element upon occurrence of any abnormality, such as overvoltage or overcurrent. A wireless power receiving device includes a power receiving coil; a rectifier unit that performs full-wave rectification of the power received by the power receiving coil and supplies the power to a load; power-receiving-side detecting unit that detects an output voltage value or an output current value from the rectifier unit; and switching unit that short-circuits one of two current paths through the rectifier unit if the value detected by the power-receiving-side detecting unit exceeds a predetermined reference value.

Abstract: A coil unit, a wireless power feeding device, a wireless power receiving device, and a wireless power transmission device are provided that can reduce high induced voltage on the metal part. A coil unit includes a power transmission coil, reactance circuits and that each form a resonant circuit together with the power transmission coil, and a metal part disposed on the same side as the back side of the power transmission coil. A ratio between a first reactance value of the first reactance circuit and a second reactance value of the second reactance circuit is set based on the ratio of the mean distance between the winding and the metal part in a part of the winding from the other end to the central portion to the mean distance between the winding and the metal part in a part of the winding from one end to the central portion.

Abstract: A coil device and a wireless power transmission device which can detect the happened open fault or short fault reliably in any one of the plurality of capacitor elements constituting the capacitor circuit. Coil device includes coil for power transmission, capacitor circuit connected to coil for power transmission and having a plurality of capacitor elements, conductive metal portion which is disposed close to coil for power transmission, and measuring portion for measuring a voltage or a current generated in metal portion.

Abstract: A coil unit, a wireless power feeding device, a wireless power receiving device, and a wireless power transmission device are provided that can reduce high induced voltage on the metal part. A coil unit includes a power transmission coil, reactance circuits and that each form a resonant circuit together with the power transmission coil, and a metal part disposed on the same side as the back side of the power transmission coil. A ratio between a first reactance value of the first reactance circuit and a second reactance value of the second reactance circuit is set based on the ratio of the mean distance between the winding and the metal part in a part of the winding from the other end to the central portion to the mean distance between the winding and the metal part in a part of the winding from one end to the central portion.

Abstract: A coil unit, a wireless power feeding device, a wireless power receiving device, and a wireless power transmission device are provided that are capable of reducing high voltage induced on the metal part. A coil unit Lu1 includes a power transmission coil L1, a first reactance circuit X10 that is connected to one end portion of the winding of the power transmission coil L1 and forms a resonant circuit together with the power transmission coil L1, a metal part SD disposed on the same side as the back side of the power transmission coil L1, and a first adjustment capacitor C10 connected between the other end portion of the winding of the power transmission coil L1 and the metal part SD.

Abstract: To provide a wireless power receiving device, and a wireless power transmission device capable of improving the reliability of a protection circuit while preventing breakage of a circuit element upon occurrence of any abnormality, such as overvoltage or overcurrent. A wireless power receiving device includes a power receiving coil; a rectifier unit that performs full-wave rectification of the power received by the power receiving coil and supplies the power to a load; power-receiving-side detecting unit that detects an output voltage value or an output current value from the rectifier unit; and switching unit that short-circuits one of two current paths through the rectifier unit if the value detected by the power-receiving-side detecting unit exceeds a predetermined reference value.