Abstract: In an insulated resonance circuit device, a first resonance circuit includes first and second LC resonance circuits electromagnetically coupled to each other and electrically insulated from each other, oscillates at a predetermined first resonance frequency based on an input AC voltage, and outputs an oscillation signal voltage. The second resonance circuit having a second resonance frequency substantially identical to the first resonance frequency resonates with the oscillation signal voltage to detect the oscillation signal voltage, and outputs the detected oscillation signal voltage. A control circuit compare the oscillation signal voltage from the second resonance circuit with a comparison signal voltage for obtaining a predetermined target output voltage and/or a predetermined target output current to generate and output gate signals for controlling a rectifier circuit.

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 first detector detects a value of a current or voltage generated by an auxiliary coil. A second detector detects a value of a current flowing through a power transmitting coil. A coupling coefficient estimator estimates a first coupling coefficient between the power transmitting coil and a power receiving coil, based on the value of the current or voltage generated by the auxiliary coil, and estimates a second coupling coefficient between the power transmitting coil and the power receiving coil, based on the value of the current flowing through the power transmitting coil. A control circuit controls a power supply circuit to stop power transmission to a power receiver apparatus when a difference between the coupling coefficients is greater than a threshold.

Abstract: A detection circuit detects at least one of a value of a current flowing through a power transmitting coil, and a value of a current or voltage generated by an auxiliary coil. A control circuit determines a transmitting frequency based on the value detected by the detection circuit, the transmitting frequency at least locally minimizing load dependence. The control circuit determines a voltage for the transmitting power at which an output voltage of a power receiver apparatus is equal to a predetermined target voltage when generating the transmitting power having the transmitting frequency determined, and controls the power supply circuit to generate the transmitting power having the transmitting frequency and voltage determined.

Abstract: 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.

Abstract: A resonance oscillator circuit is provided to include first and second oscillators. The first oscillator includes a first LC resonator circuit and an amplifier element, and oscillates by shifting a phase of an output voltage with a predetermined phase difference and feeding the output voltage back to the amplifier element. The second oscillator oscillates by generating a gate signal, which has a frequency identical to that of the output voltage, and drives the amplifier element, by shifting the phase of the output voltage with the phase difference and feeding the gate signal back to an input terminal of the amplifier element, by using the amplifier element as a switching element and using the first oscillator as a feedback circuit. The phase difference is a value substantially independent of an inductance of the first LC resonator circuit and a load, to which the output voltage is applied.

Abstract: A first detector detects a value of a current or voltage generated by an auxiliary coil. A second detector detects a value of a current flowing through a power transmitting coil. A coupling coefficient estimator estimates a first coupling coefficient between the power transmitting coil and a power receiving coil, based on the value of the current or voltage generated by the auxiliary coil, and estimates a second coupling coefficient between the power transmitting coil and the power receiving coil, based on the value of the current flowing through the power transmitting coil. A control circuit controls a power supply circuit to stop power transmission to a power receiver apparatus when a difference between the coupling coefficients is greater than a threshold.

Abstract: A detection circuit detects at least one of a value of a current flowing through a power transmitting coil, and a value of a current or voltage generated by an auxiliary coil. A control circuit determines a transmitting frequency based on the value detected by the detection circuit, the transmitting frequency at least locally minimizing load dependence. The control circuit determines a voltage for the transmitting power at which an output voltage of a power receiver apparatus is equal to a predetermined target voltage when generating the transmitting power having the transmitting frequency determined, and controls the power supply circuit to generate the transmitting power having the transmitting frequency and voltage determined.

Abstract: A resonance oscillator circuit is provided to include first and second oscillators. The first oscillator includes a first LC resonator circuit and an amplifier element, and oscillates by shifting a phase of an output voltage with a predetermined phase difference and feeding the output voltage back to the amplifier element. The second oscillator oscillates by generating a gate signal, which has a frequency identical to that of the output voltage, and drives the amplifier element, by shifting the phase of the output voltage with the phase difference and feeding the gate signal back to an input terminal of the amplifier element, by using the amplifier element as a switching element and using the first oscillator as a feedback circuit. The phase difference is a value substantially independent of an inductance of the first LC resonator circuit and a load, to which the output voltage is applied.