Abstract: A wireless power feeder 116 feeds power from a feeding coil L2 to a receiving coil L3 by wireless based on a magnetic field resonance phenomenon between the feeding coil L2 and receiving coil L3. A power transmission control circuit 200 supplies AC current at a drive frequency fo to the feeding coil L2. The feeding coil L2 outputs AC power in substantially a non-resonant state with respect to circuit elements on the power feeding side. Then, power is supplied to a receiving coil circuit 130 by a magnetic field resonance between the feeding coil L2 and receiving coil L3.

Abstract: The present invention aims to provide a coil unit for improving an accuracy in detecting foreign matter and an apparatus for detecting foreign matter which improves the accuracy in detecting foreign matter when a power is transmitted in a contactless manner. A power feeding coil unit L100 (a coil unit) of the present invention is provided with a power feeding coil L1 (a coil for power transmission) and an apparatus D100 for detecting foreign matter. The apparatus D100 for detecting foreign matter is provided with a plurality of resonators R1 having a resonator coil M1 and a resonator capacitor C1 and also an excitation coil E1 for exciting the plurality of resonators R1. The plurality of resonators R1 are disposed to cover at least an area interlinking with a magnetic flux generated by the power feeding coil L1 and to decrease an influence of mutual inductance.

Abstract: A power feeding coil unit (a coil unit) is provided with a power feeding coil (a coil for power transmission) and an apparatus for detecting foreign matter. The apparatus for detecting foreign matter is provided with a plurality of resonators having a resonator coil and capacitor and also an excitation coil for exciting the plurality of resonators. The plurality of resonators are disposed in rows and columns to cover at least an area interlinking with a magnetic flux generated by the power feeding coil. The excitation coil makes resonators adjacent in a row direction and a column direction among the plurality of resonators to generate an alternating magnetic field with resonance frequencies different from each other within a frequency band in which the power feeding coil is not excited.

Abstract: A wireless headphone system 102 includes a headphone 144 and a headphone stand 104. The headphone 144 has two ear cups 150a and 150b. The ear cup 150a incorporates a receiving coil L3 and a capacitor C3. The ear cup 150b incorporates a charge controller 138 and a secondary battery 112. The headphone stand 104 incorporates a feeding coil L2. When the headphone 144 is set in the headphone stand 104, AC power is supplied from the feeding coil L2 to the receiving coil L3, and the secondary battery 112 of the headphone 144 is charged with the AC power.

Abstract: A power receiving device and power feeding device improve convenience of the user by increasing the freedom of configuring the power receiving device with respect to the power feeding device and freedom of configuring the power feeding device with respect to the power receiving device, and inhibit large size of machines. The power receiving device includes: plurality of surfaces; and inside a power receiving coil, and the power receiving coil includes: a winding portion with wires wound; and an opening portion surrounded by the winding portion and having two opposite opening ends. By disposing the power receiving coil so an end face of at least one of the two opening ends is nonparallel (excluding perpendicular) to two or more surfaces of the power receiving device, a power receiving area capable of receiving power from the power feeding device formed on the two or more surfaces of the power receiving device.

Abstract: Power is fed from a feeding coil L2 to a receiving coil L3 using magnetic resonance. The receiving coil L3 is connected in series to a capacitor C3 to constitute a receiving coil circuit 130. The receiving coil L3 is further connected to an adjustment coil L5. By adjusting the inductance of the adjustment coil L5, the resonance frequency of the receiving coil circuit 130 can be adjusted. Since the axial direction of the adjustment coil L5 is at right angles to the power feeding direction, an electromotive force does not occur in the adjustment coil L5.

Abstract: Power is fed from a feeding coil to a receiving coil L3 by magnetic resonance. The receiving coil L3 and a capacitor C3 are connected in series to constitute a receiving coil circuit. A loading coil L4 electromagnetically coupled to the receiving coil L3 is connected to a load through a rectification circuit 142 to constitute a loading circuit. Placing the rectification circuit 142 on a first flat plate electrode 132 of the capacitor C3 allows heat generated from the rectification circuit 142 to escape to the first flat plate electrode 132.

Abstract: A coil device for wireless power transmission mounted on a movable body includes a coil body and a magnetic flux conductor. A winding forming the coil body mainly contains aluminum, and the magnetic flux conductor contains a magnetic material and a resin.

Abstract: Power is fed from a feeding coil to a receiving coil using magnetic resonance. The feeding coil is wound in a first layer substrate 144 of a multilayer substrate 116 with a space provided between the coil conductor thereof and further wound in a second later substrate 146 with a space provided between the coil conductor thereof. The feeding coil is wound such that a coil conductor 106a in the first layer and a coil conductive wire 106b in the second layer do not overlap each other as viewed in the axial direction (z-axis direction).

Abstract: A power receiving device, a power feeding device, and a wireless power transmission device are provided. The power receiving device receives power wirelessly transmitted from the power feeding device and includes one or more power receiving units. At least one of the power receiving units in the power receiving device is disposed along two or more surfaces which form the outer shape of the power receiving device and are not parallel to each other.

Abstract: Power is fed from a feeding coil L2 to a receiving coil L3 by magnetic resonance. A VCO alternately turns ON/OFF switching transistors Q1 and Q2 at a drive frequency fo, whereby AC current is fed to the feeding coil L2, and then the AC current is fed from the feeding coil L2 to the receiving coil L3. A phase detection circuit detects a phase difference between the current phase and voltage phase, and the VCO adjusts the drive frequency fo such that the phase difference becomes zero. In a current phase detection circuit and a voltage phase detection circuit, detection values of the current and voltage phases can be changed, respectively and intentionally.

Abstract: Power is fed from a feeding coil L2 to a receiving coil L3 by magnetic resonance. A VCO 202 alternately turns ON/OFF switching transistors Q1 and Q2 at a drive frequency fo, whereby AC power is fed to the feeding coil L2, and then the AC power is fed from the feeding coil L2 to the receiving coil L3. A phase detection circuit 114 detects a phase difference between the current phase and voltage phase, and the VCO 202 adjusts the drive frequency fo such that the phase difference becomes zero. When load voltage is changed, the detected current phase value is adjusted with the result that the drive frequency fo is adjusted.

Abstract: Power is transmitted from a feeding coil L2 to a receiving coil L3 by magnetic resonance. A VCO 202 alternately turns ON/OFF switching transistors Q1 and Q2 to feed AC current to the feeding coil L2, whereby the AC power is fed from the feeding coil L2 to the receiving coil L3. An AC magnetic field generated by AC current IS flowing in the feeding coil L2 causes inductive current ISS to flow in a detection coil LSS. A phase detection circuit 150 compares the phase of AC voltage generated by the VCO 202 and phase of the inductive current ISS to detect the phase difference between voltage and current phases and generates phase difference indicating voltage indicating the magnitude of the phase difference. The reset circuit 102 forcibly reduces the phase difference indicating voltage when the phase difference indicating voltage exceeds a predetermined threshold.

Abstract: Power is fed from a power feeding coil L2 to a power receiving coil L3 by magnetic resonance. A VCO 202 alternately turns ON/OFF switching transistors Q1 and Q2 at a drive frequency fo, whereby AC power is supplied to the power feeding coil L2, and then the AC power is supplied from the power feeding coil L2 to the power receiving coil L3. A phase detection circuit 114 detects a phase difference between current and voltage phases, and the VCO 202 adjusts the drive frequency fo such that the phase difference becomes zero. When load voltage is changed, the detected voltage phase value is adjusted with the result that the drive frequency fo is adjusted.

Abstract: A resonance circuit is a circuit in which capacitors, a load, and coils are connected. AC power is fed by wireless from feeding electrodes of the capacitors to receiving electrodes thereof. The oscillator alternately turns on/off switching transistors to thereby supply AC power to the resonance circuit. An AC magnetic field generated by AC current flowing in the resonance circuit causes inductive current to flow in a detection coil. A phase detection circuit compares the phase of AC voltage generated by the oscillator and phase of the inductive current to thereby detect the phase difference between the voltage phase and current phase.

Abstract: A wireless power feeder 116 feeds power from a feeding coil L2 in the ground to a receiving coil L3 incorporated in an EV by wireless using a magnetic field resonance phenomenon between the feeding coil L2 and receiving coil L3. A plurality of feeding coils L2a to L2d are buried in the ground. Receivers 112a to 112d are buried in corresponding respectively with the feeding coils L2a to L2d. The plurality of receivers 112 each receive a position signal transmitted from a transmitter 110 of the EV. A feeding coil circuit 120 supplies AC power to the feeding coil L2 corresponding to the receiver 112 that has received the position signal to allow the feeding coil L2 to feed power to the receiving coil L3 by wireless.

Abstract: Power is fed from a feeding coil to a receiving coil by magnetic resonance. A drive circuit outputs an IN signal generated by an oscillator as a DR signal to alternately turn ON/OFF switching transistors at a resonance frequency, whereby AC current is fed to the feeding coil, and then the AC current is fed from the feeding coil to the receiving coil. An enable signal generation circuit generates an EN signal at a frequency lower than the resonance frequency. The drive circuit outputs the DR signal only while the EN signal assumes a high level. Transmission power from a wireless feeder to a wireless receiver is controlled by adjusting the duty ratio of the EN signal.

Abstract: A wireless power feeder 116 feeds power by wireless from a feeding coil L2 to a receiving coil L3 using a magnetic field resonance phenomenon. A power transmission control circuit 200 supplies AC power at a drive frequency fo to the feeding coil L2, thereby making the feeding coil L2 feed the AC power to the receiving coil L3. A phase detection circuit 150 detects the phase difference between the voltage phase and current phase of the AC power. Concretely, the phase detection circuit compares a first detection time period during which a signal T2 assumes a high level and a second detection time period during which a signal S2 assumes a high level and detects the length of the time period in which the first and second detection periods overlap each other to detect the phase difference.

Abstract: Power is fed from a feeding coil L2 to a receiving coil L3 by magnetic resonance. An oscillator 202 alternately turns ON/OFF switching transistors Q1 and Q2 to cause AC current IS of drive frequency fo to flow in a transformer T2 primary coil Lb. The AC current IS causes AC current I1 to flow in an exciting coil L1 and causes AC current I2 to flow in the feeding coil L2.

Abstract: Power is fed from a feeding coil L2 to a receiving coil L3 by magnetic resonance. A VCO 202 alternately turns ON/OFF switching transistors Q1 and Q2 at a drive frequency fo, whereby AC power is fed to the feeding coil L2, and then the AC power is fed from the feeding coil L2 to the receiving coil L3. A phase detection circuit 114 detects a phase difference between the current phase and voltage phase, and the VCO 202 adjusts the drive frequency fo such that the phase difference becomes zero. When load voltage is changed, the detected current phase value is adjusted with the result that the drive frequency fo is adjusted.