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: A wireless power feeder which performs power feed by a non-contact method to a wireless power receiver having a power receive coil, this wireless power feeder having a power feed coil; and a control circuit having a phase delay device which generates a delayed AC voltage where the phase of the output AC voltage is delayed; a magnetic sensor biased by the delayed AC voltage and detects a magnetic field generated by power receive coil; phase detection circuits which generate phase difference instruction voltages corresponding to a phase difference between an output voltage from the magnetic sensor and a comparison voltage, on the basis of the output voltage and the comparison voltage; and AC current generation circuits which generate the output AC voltage having a frequency based on the phase difference instruction voltage, and generate the AC current having a frequency corresponding to the frequency of the output AC voltage.

Abstract: A wireless power feeder which performs power feed to a wireless power receiver having a power receive resonance circuit including a power receive coil and a power receive capacitor, this wireless power feeder including: a power feed coil; a resonance current detector; and a control circuit; wherein the power feed coil does not substantially constitute a resonance circuit; the current detector has a detection resonance circuit including a detection coil and a detection capacitor, and detects a resonance current of the power receive resonance circuit; the winding region of the detection coil in the current detector is smaller than the winding region of the power feed coil; and the detection coil in the current detector is disposed such that the central winding axis thereof forms an angle of not less than 80° and not more than 100° with respect to magnetic field vectors generated by the power feed coil.

Abstract: A wireless power receiver according to an embodiment of the present invention is a wireless power receiver which acquire power by a non-contact method from a wireless power feeder, the wireless power receiver having: a power receive resonance circuit that includes a power receive coil and power receive capacitor and acquires power from a power feed coil of the wireless power feeder by means of the power receive coil on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil; a power receive load coil that receives the power fed from the power receive coil by a non-contact method; and an impedance converter that is arranged between the power receive load coil and a load and in which a primary impedance connected to the power receive load coil is higher than a secondary impedance connected to the load.

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 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: A feeding body 106 has a cylindrical part capable of housing a light source cartridge 104. A feeding coil L2 for supplying AC power to the light source cartridge 104 is buried in the bottom surface of the cylindrical part of the feeding body 106. A power transmission control circuit 108 supplies AC power to the feeding coil L2. The feeding body 106 can change the insertion depth of the light source cartridge 104 and has, in the inner wall, a screw groove for stabilizing the position of the light source cartridge.

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 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 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: 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 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: A wireless power feeder which performs power feed by a non-contact method to a wireless power receiver having a power receive coil, this wireless power feeder having a power feed coil; and a control circuit having a phase delay device which generates a delayed AC voltage where the phase of the output AC voltage is delayed; a magnetic sensor biased by the delayed AC voltage and detects a magnetic field generated by power receive coil; phase detection circuits which generate phase difference instruction voltages corresponding to a phase difference between an output voltage from the magnetic sensor and a comparison voltage, on the basis of the output voltage and the comparison voltage; and AC current generation circuits which generate the output AC voltage having a frequency based on the phase difference instruction voltage, and generate the AC current having a frequency corresponding to the frequency of the output AC voltage.

Abstract: A wireless power transmission system aims to feed power by wireless from a feeding coil to a receiving coil using a magnetic field resonance phenomenon between the feeding coil and receiving coil. The wireless power transmission system includes the feeding coil, receiving coil, a loading coil, and a power transmission control circuit. The power transmission control circuit supplies AC power to the feeding coil so as to make the feeding coil feed the AC power to the receiving coil. The loading coil is magnetically coupled to the receiving coil to receive the AC power from the receiving coil. A light control glass receives the AC power from the loading coil. The transparency of the light control glass is changed by the AC power received by the loading coil.

Abstract: Power is transmitted based on magnetic resonance from a feeding coil L2 to a receiving coil L3. An adjustment circuit 104 of a wireless power receiver 118 is supplied with a first AC power received by the receiving coil L3. An adjustment circuit 104 includes a DC circuit 106 and an AC circuit 150. The DC circuit 106 converts the first AC power into DC power. The AC circuit 150 converts the DC power into a second AC power. The adjustment circuit 104 outputs the DC power and second AC power simultaneously or selectively through separate channels.

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: A wireless power transmission system according to an embodiment of the present invention is a wireless power transmission system performing non-contact power transmission from a wireless power feeder selectively to a plurality of wireless power receivers, and each of the plurality of wireless power receivers comprises a power receive resonance circuit including a power receive coil and a power receive capacitor, and the wireless power feeder comprises a power feed coil and a control circuit supplying AC power to the power feed coil. The control circuit in the wireless power feeder performs power supply selectively to the plurality of wireless power receivers by changing frequency of the AC power on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil.

Abstract: A wireless power feeder which performs power feed to a wireless power receiver having a power receive resonance circuit including a power receive coil and a power receive capacitor, this wireless power feeder including: a power feed coil; a resonance current detector; and a control circuit; wherein the power feed coil does not substantially constitute a resonance circuit; the current detector has a detection resonance circuit including a detection coil and a detection capacitor, and detects a resonance current of the power receive resonance circuit; the winding region of the detection coil in the current detector is smaller than the winding region of the power feed coil; and the detection coil in the current detector is disposed such that the central winding axis thereof forms an angle of not less than 80° and not more than 100° with respect to magnetic field vectors generated by the power feed coil.

Abstract: A wireless power receiver according to an embodiment of the present invention is a wireless power receiver which acquire power by a non-contact method from a wireless power feeder, the wireless power receiver having: a power receive resonance circuit that includes a power receive coil and power receive capacitor and acquires power from a power feed coil of the wireless power feeder by means of the power receive coil on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil; a power receive load coil that receives the power fed from the power receive coil by a non-contact method; and an impedance converter that is arranged between the power receive load coil and a load and in which a primary impedance connected to the power receive load coil is higher than a secondary impedance connected to the load.

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.