Omron Corporation

Yuki Ito

Goro Nakao

Taichi Mishima

Yusuke Kawai

Hiroaki Ota

Ken Onozaka

Takeshi Uematsu

Atsushi Nomura

Mitsunori Sugiura

Shingo Nagaoka

Kenichi Tabata

Takashi Hyodo

Daiki Ando

Hironori Tauchi

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.

Contactless power feeding apparatus

A contactless power feed apparatushas a relay circuitrelaying power transmitted from a power transmission deviceto a power reception devicein a contactless manner. The power transmission devicehas: a transmission coiltransmitting AC power to the relay circuit. The relay circuithas: a first coil, electromagnetically coupled with the transmission coiland receiving the AC power from the transmission coil; a second coil, transmitting the AC power to the power reception device; and a resonant capacitor, resonating with the AC power supplied to the transmission coiltogether with the first and second coils. The power reception devicehas: a resonant circuit, having a reception coilreceiving AC power from the second coilby being electromagnetically coupled with the second coilof the relay circuit

Contactless power feed apparatus

A power reception deviceincludes: an estimation circuitestimating a load resistance of an entire contactless power feed apparatus; and a reception-side communicatortransmitting an estimated value of the load resistance of the entire contactless power feed apparatusto a power transmission device. The power transmission devicehas a power supply circuitsupplying AC power to a transmission coilsupplying power to the power reception device. The power transmission devicefurther includes a control circuitdecreasing an input/output gain of a transmission-side DC-DC converterincluded in the power supply circuitby 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.

Contactless power feed apparatus and power transmission method

A foreign matter detection device includes: a plurality of detection coils (-to-) between a transmission coil () of a power transmission device () and a reception coil () of a power reception device (), through which power is transmitted in a contactless manner; a plurality of capacitors (-to-) forming, for each of the detection coils, a resonance circuit together with the detection coil; a power supply circuit () supplying AC power having a predetermined frequency to each detection coil; and a detection circuit () detecting a voltage output from each detection coil and detecting a foreign matter entering between the transmission coil () and the reception coil () 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 (-to-) to be ignored.

Foreign matter detection device

A control circuit controls a power supply circuit to generate transmitting power having a frequency varying within a frequency range. The control circuit determines a stably transmitting frequency based on a detected output voltage of a power receiver apparatus, the stably transmitting frequency indicating a frequency of the transmitting power at which dependency of the output voltage on a load value of the power receiver apparatus is at least locally minimized within the frequency range. The control circuit determines a transmitting voltage based on the detected output voltage, the transmitting voltage indicating a voltage of the transmitting power at which the output voltage reaches a target voltage when generating transmitting power having the stably transmitting frequency. The control circuit controls the power supply circuit to generate transmitting power having the stably transmitting frequency and the transmitting voltage.

Contactless power transmission system capable of controlling power transmitter apparatus to stably supply load device with required power

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.

An unbalanced failure detector circuit according to one aspect of the present disclosure is provided for detecting an unbalanced failure of an electronic device apparatus including electronic devices, and the electronic device apparatus includes a plurality of current paths connected in parallel. The unbalanced failure detector circuit includes a detector unit, and a controller. The detector unit has a plurality of coils connected in series and arranged to surround the plurality of current paths, respectively, and is configured to output a coil sum voltage which is a sum of induced voltages generated across the plurality of coils by currents flowing through the plurality of current paths. The controller is configured to detect the unbalanced failure of the electronic device apparatus when the coil sum voltage outputted from the detector unit exceeds a predetermined value range.

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KYOTO, Japan

Yuki Ito