Abstract: A power receiver device of a non-contact power feeding device includes a plurality of resonance circuits that receive power from a power transmitter device, a voltage detection circuit that detects an output voltage from the plurality of resonance circuits, and a control circuit. Receiver coils of the plurality of resonance circuits are arranged so as to be electromagnetically coupled to each other. At least one of resonance circuits includes a variable capacitance circuit that is connected to the receiver coil of the resonance circuit and is regulatable in capacitance. The control circuit regulates the capacitance of the variable capacitance circuit in accordance with the output voltage.

Abstract: A winding of a transmission coil included in a power transmission device of a contactless power feed apparatus and serving to transmit AC power to a power reception device contactlessly is formed of a wiring pattern provided on a substrate. The transmission coil is divided into partial coils arranged coaxially. Each of the partial coils is formed such that, among the partial coils, a number of turns of a winding included in a partial coil is larger as the partial coil is located more outwardly.

Abstract: A contactless power feed apparatus 1 has a relay circuit 4 relaying power transmitted from a power transmission device 2 to a power reception device 3 in a contactless manner. The power transmission device 2 has: a transmission coil 12 transmitting AC power to the relay circuit 4. The relay circuit 4 has: a first coil 31, electromagnetically coupled with the transmission coil 12 and receiving the AC power from the transmission coil 12; a second coil 32, transmitting the AC power to the power reception device 3; and a resonant capacitor 33, resonating with the AC power supplied to the transmission coil 12 together with the first and second coils 31, 32. The power reception device 3 has: a resonant circuit 20, having a reception coil 21 receiving AC power from the second coil 32 by being electromagnetically coupled with the second coil 32 of the relay circuit 4.

Abstract: A power reception device 3 includes: an estimation circuit 28 estimating a load resistance of an entire contactless power feed apparatus 1; and a reception-side communicator 27 transmitting an estimated value of the load resistance of the entire contactless power feed apparatus 1 to a power transmission device 2. The power transmission device 2 has a power supply circuit 11 supplying AC power to a transmission coil 12 supplying power to the power reception device 3. The power transmission device 2 further includes a control circuit 18 decreasing an input/output gain of a transmission-side DC-DC converter 31 included in the power supply circuit 11 by a predetermined amount when the estimated value of the load resistance is less than a predetermined allowed lower limit, and maintaining or increasing the input/output gain when the estimated value of the load resistance is equal to or greater than the predetermined allowed lower limit.

Abstract: A foreign object detector includes detection coils between a transmitter coil in a transmitter device and a receiver coil in a receiver device, a power supply circuit that supplies AC power having a predetermined frequency to each detection coil through a feeder coil located to be electromagnetically coupled to each detection coil, and a detection circuit that detects, while power to be transmitted to the receiver coil is being supplied to the transmitter coil, a criteria voltage to be a criterion for foreign object detection output from each detection coil at a start of power supply from the power supply circuit and outputs a signal to stop power supply to the transmitter coil in response to the criteria voltage for any detection coil deviating from a predetermined range. The transmitter device transmits power to the receiver device contactlessly.

Abstract: A cage is provided which is less likely to be deformed by a centrifugal force, and in which the strength of a weld is less likely to decrease. Each horn portion includes a base wall axially connected to a ring portion, and located between pockets; and a pair of claws separated from each other. The pair of claws each has a pocket inner surface facing the pocket; and an opposed surface (14) on the side opposite from the pocket inner surface. The base wall includes a pair of connection portions axially connecting the respective claws to the ring portion; and an intermediate portion circumferentially connecting the connection portions to each other. A weld is disposed in a resin area consisting of one of the claws, one of the connection portions, and a circumferential section of the ring portion.

Abstract: A foreign matter detection device includes: a plurality of detection coils (43-1 to 43-n) between a transmission coil (12) of a power transmission device (2) and a reception coil (21) of a power reception device (3), through which power is transmitted in a contactless manner; a plurality of capacitors (44-1 to 44-n) forming, for each of the detection coils, a resonance circuit together with the detection coil; a power supply circuit (41) supplying AC power having a predetermined frequency to each detection coil; and a detection circuit (45) detecting a voltage output from each detection coil and detecting a foreign matter entering between the transmission coil (12) and the reception coil (21) according to the voltage detected. Then, each detection coil is arranged to overlap by a predetermined amount that allows electromagnetic coupling between adjacent two of the detection coils (43-1 to 43-n) to be ignored.

Abstract: A power reception device 3 includes: an estimation circuit 28 estimating a load resistance of an entire contactless power feed apparatus 1; and a reception-side communicator 27 transmitting an estimated value of the load resistance of the entire contactless power feed apparatus 1 to a power transmission device 2. The power transmission device 2 has a power supply circuit 11 supplying AC power to a transmission coil 12 supplying power to the power reception device 3. The power transmission device 2 further includes a control circuit 18 decreasing an input/output gain of a transmission-side DC-DC converter 31 included in the power supply circuit 11 by a predetermined amount when the estimated value of the load resistance is less than a predetermined allowed lower limit, and maintaining or increasing the input/output gain when the estimated value of the load resistance is equal to or greater than the predetermined allowed lower limit.

Abstract: A winding of a transmission coil included in a power transmission device of a contactless power feed apparatus and serving to transmit AC power to a power reception device contactlessly is formed of a wiring pattern provided on a substrate. The transmission coil is divided into partial coils arranged coaxially. Each of the partial coils is formed such that, among the partial coils, a number of turns of a winding included in a partial coil is larger as the partial coil is located more outwardly.

Abstract: A contactless power feed apparatus 1 has a relay circuit 4 relaying power transmitted from a power transmission device 2 to a power reception device 3 in a contactless manner. The power transmission device 2 has: a transmission coil 12 transmitting AC power to the relay circuit 4. The relay circuit 4 has: a first coil 31, electromagnetically coupled with the transmission coil 12 and receiving the AC power from the transmission coil 12; a second coil 32, transmitting the AC power to the power reception device 3; and a resonant capacitor 33, resonating with the AC power supplied to the transmission coil 12 together with the first and second coils 31, 32. The power reception device 3 has: a resonant circuit 20, having a reception coil 21 receiving AC power from the second coil 32 by being electromagnetically coupled with the second coil 32 of the relay circuit 4.

Abstract: A power receiver device of a non-contact power feeding device includes a plurality of resonance circuits that receive power from a power transmitter device, and a power receiver circuit that outputs, to a load circuit, the power received from the power transmitter device by the plurality of resonance circuits. Each of the plurality of resonance circuits includes a receiver coil that receives power from a transmitter coil of the power transmitter device, and a resonance capacitor that resonates, together with the receiver coil, with AC power supplied to the transmitter coil of the power transmitter device. The receiver coils of the plurality of resonance circuits are arranged so as to be electromagnetically coupled to each other.

Abstract: A power transmission device includes power transmission coils, at least one power supply circuit, a communicator, and a control circuit. The power transmission coils transmit power to a power reception device via a power reception coil. The at least one power supply circuit supplies AC power to the power transmission coils, respectively. The communicator receives a signal indicating a power reception status of the power reception device from the power reception device. According to the power reception status, the control circuit selects a power transmission coil with a highest efficiency of power transmission to the power reception device among the power transmission coils to serve as the power transmission coil for power transmission to the power reception device, and controls the at least one power supply circuit so that AC power is supplied to the selected power transmission coil and is not supplied to an unselected power transmission coil.

Abstract: A power transmitting apparatus included in a contactless power feeding apparatus includes a power supply circuit that supplies AC power having a predetermined drive frequency to a transmission coil for supplying power to a power receiving apparatus, a power receiving circuit that receives returning power transmitted from the power receiving apparatus, a control circuit that controls, according to a voltage of the returning power, the power supply circuit such that an output voltage of the power receiving apparatus is in a predetermined allowable range. Also, the power receiving apparatus includes a resonant circuit for receiving power via the transmission coil of the power transmitting apparatus, a rectifier circuit that rectifies power received via the resonant circuit, and a power transmitting circuit that transmits the returning power according to a voltage of power output from the rectifier circuit to the power transmitting apparatus.

Abstract: A power transmitting apparatus included in the contactless power feeding apparatus includes a power supply circuit that supplies AC power having a predetermined drive frequency to a transmission coil for supplying power to a power receiving apparatus, a first coil and a first capacitor that are connected between the power supply circuit and the transmission coil, a second capacitor that is connected at first end to the first capacitor and is connected at a second end to the second end of the transmission coil, and a control circuit. Also, the power receiving apparatus includes a receiver coil for receiving power, and a resonant circuit that includes a resonance capacitor that resonates together with the receiver coil. Also, the control circuit of the power transmitting apparatus controls the power supply circuit such that the predetermined drive frequency falls within a predetermined frequency range including a resonance frequency of the resonant circuit.

Abstract: A power transmission device includes a transmission coil that supplies power to a power reception device, a power supply circuit that converts DC power supplied from a DC power source via a plurality of switching elements connected in a full bridge shape or a half bridge shape between DC power sources and the transmission coil into AC power and supplies the AC power to the transmission coil, a phase adjustment circuit having an LC series circuit connected in parallel with the transmission coil and a switching element connected in series with the LC series circuit, and a control circuit that controls switching on and off of the switching element of the phase adjustment circuit in accordance with a measured value of an amount of current when any of the plurality of switching elements of the power supply circuit is turned off by a current detection circuit.

Abstract: A power transmitter device of a non-contact power feeding device includes a transmitter coil configured to supply power to the power receiver device, a power supply circuit including a plurality of switching elements connected between a DC power supply and the transmitter coil in a full-bridge configuration or a half-bridge configuration. The power supply circuit may be configured to switch the plurality of switching elements to an on or off state at a switching frequency to convert DC power supplied from the DC power supply into AC power having the switching frequency and supply the AC power to the transmitter coil, and a phase control circuit including at least one LC series circuit connected to both ends of the transmitter coil.

Abstract: A foreign object detector includes detection coils between a transmitter coil in a transmitter device and a receiver coil in a receiver device, a power supply circuit that supplies AC power having a predetermined frequency to each detection coil through a feeder coil located to be electromagnetically coupled to each detection coil, and a detection circuit that detects, while power to be transmitted to the receiver coil is being supplied to the transmitter coil, a criteria voltage to be a criterion for foreign object detection output from each detection coil at a start of power supply from the power supply circuit and outputs a signal to stop power supply to the transmitter coil in response to the criteria voltage for any detection coil deviating from a predetermined range. The transmitter device transmits power to the receiver device contactlessly.

Abstract: A foreign object detector includes multiple detection coils located between a transmitter coil in a transmitter device and a receiver coil in a receiver device to be electromagnetically coupled to one another, multiple capacitors each forming a resonant circuit together with a corresponding detection coil of the detection coils, a power supply circuit that supplies alternating current power having a predetermined frequency to each of the detection coils through a feeder coil located to be electromagnetically coupled to each of the detection coils, and a detection circuit that detects a voltage output from each of the detection coils and detects a foreign object between the transmitter coil and the receiver coil based on the detected voltage. The transmitter device transmits power to the receiver device contactlessly.

Abstract: A power transfer device includes a power transfer coil that transfers power to another device in a non-contact manner, a power transmission and reception circuit that supplies power to the power transfer coil or outputs power received by the power transfer coil to a load circuit, and a protection coil disposed between the power transfer coil and the power transmission and reception circuit to prevent a magnetic flux generated by the power transfer coil from reaching the power transmission and reception circuit. The protection coil includes an air-core coil formed of a wiring pattern of a conductor provided on a board disposed between the power transfer coil and the power transmission and reception circuit, and at least one core coil connected in series to the air-core coil.

Abstract: A power reception device of a non-contact power feeding device has: a resonant circuit having a reception coil configured to receive electric power from a power transmission device and a resonant capacitor connected in series with the reception coil; a first rectifier circuit configured to rectify electric power received via the resonant circuit; a smoothing capacitor connected to the first rectifier circuit and configured to smooth a voltage outputted from the first rectifier circuit; a sub-coil arranged to be capable of being electromagnetically coupled to the reception coil; and a second rectifier circuit connected between the sub-coil and the smoothing capacitor, and configured to output electric power according to a voltage generated in the sub-coil to the smoothing capacitor in response to a voltage obtained by rectifying a voltage generated in the sub-coil being higher than a voltage between both terminals of the smoothing capacitor.