Abstract: A non-contact power transmission device equipped with a ground-side device and a vehicle-side device. The ground-side device has a primary-side coil to which alternating-current power is input. The vehicle-side device includes a secondary-side coil, a battery, a secondary-side matching device, and a charging device. The secondary-side coil receives alternating-current power from the primary-side coil in a non-contact manner. The secondary-side matching device is provided between the secondary-side coil and the battery, and has a predetermined fixed inductance and fixed capacitance. The charging device has a switching element that performs a switching operation with a prescribed cycle. The charging device adjusts the duty ratio of the switching operation in accordance with the impedance of a load.

Abstract: A contactless power transmission device includes a switching unit that switches a power transmission line so that a first power is transmitted through the first line when an AC power supply outputs a first AC power and so that a second power is transmitted through a second line when the AC power supply outputs a second AC power. An impedance conversion unit is arranged on the second line that converts an impedance from an output of the AC power supply to a variable load when the second power is transmitted through the second line to approach an impedance from the output of the AC power supply to the variable load when the first power is transmitted through the first line.

Abstract: Power supply side equipment comprises a high-frequency power supply, a matching box, a primary side resonance coil, an output impedance variable unit, a matching state detection unit, and a control unit. By a magnetic field resonance, the primary side resonance coil transmits power in a non-contact manner to a load through a secondary side resonance coil. At least the matching box, the primary side resonance coil, the secondary side resonance coil, and the load constitute a resonance system having a resonant frequency. The matching state detection unit detects the matching state between the input impedance of the resonance system and the output impedance of the high-frequency power supply at the resonant frequency. The control unit adjusts the output impedance variable unit and the matching box according to the detection result by the matching state detection unit so that the input impedance of the resonance system and the output impedance of the high-frequency power supply match each other.

Abstract: A power receiving device receives alternating current power in a wireless manner from a power supply device including an alternating current power supply and a primary coil. The power receiving device includes a secondary coil, a variable load, an impedance conversion unit, and an acknowledgement unit. Under a situation in which the acknowledgement unit acknowledges that the value of the alternating current power output from the alternating current power supply is unvaried, the impedance of the impedance conversion unit is variably controlled when an electrical property that is dependent on a relative position of the primary coil and the secondary coil varies.

Abstract: A power receiving device receives alternating current power in a wireless manner from a power supply device including a primary coil that receives the alternating current power. The power receiving device includes a secondary coil, a variable load, a first impedance conversion unit, a second impedance conversion unit, a fixed load, and a switch. The switch switches an output destination, to which the alternating current power received by the secondary coil is output from the first impedance conversion unit, to the fixed load or to the second impedance conversion unit and the variable load.

Abstract: A power-receiving device includes a secondary coil, which wirelessly receives AC power from a power-supply device having a primary coil, a variable load, in which an impedance changes in accordance with the power value of the input power, a PFC circuit having a first switching element, and a DC/DC converter having a second switching element. The PFC circuit rectifies the AC power received by the secondary coil and improves the power factor by adjusting the duty cycle in switching operation of the first switching element in accordance with the impedance fluctuation of the variable load. The DC/DC converter is configured to convert the voltage of the DC power to a different voltage and output the converted voltage to the variable load, and to adjust the duty cycle in switching operation of the second switching element in accordance with the impedance fluctuation of the variable load.

Abstract: A non-contact power transmission device equipped with a ground-side device and a vehicle-side device. The ground-side device has a primary-side coil to which alternating-current power is input. The vehicle-side device includes a secondary-side coil, a battery, a secondary-side matching device, and a charging device. The secondary-side coil receives alternating-current power from the primary-side coil in a non-contact manner. The secondary-side matching device is provided between the secondary-side coil and the battery, and has a predetermined fixed inductance and fixed capacitance. The charging device has a switching element that performs a switching operation with a prescribed cycle. The charging device adjusts the duty ratio of the switching operation in accordance with the impedance of a load.

Abstract: Power supply side equipment comprises a high-frequency power supply, a matching box, a primary side resonance coil, an output impedance variable unit, a matching state detection unit, and a control unit. By a magnetic field resonance, the primary side resonance coil transmits power in a non-contact manner to a load through a secondary side resonance coil. At least the matching box, the primary side resonance coil, the secondary side resonance coil, and the load constitute a resonance system having a resonant frequency. The matching state detection unit detects the matching state between the input impedance of the resonance system and the output impedance of the high-frequency power supply at the resonant frequency. The control unit adjusts the output impedance variable unit and the matching box according to the detection result by the matching state detection unit so that the input impedance of the resonance system and the output impedance of the high-frequency power supply match each other.

Abstract: A contactless power transmission device includes a switching unit that switches a power transmission line so that a first power is transmitted through the first line when an AC power supply outputs a first AC power and so that a second power is transmitted through a second line when the AC power supply outputs a second AC power. An impedance conversion unit is arranged on the second line that converts an impedance from an output of the AC power supply to a variable load when the second power is transmitted through the second line to approach an impedance from the output of the AC power supply to the variable load when the first power is transmitted through the first line.

Abstract: In control over a contactless power supply system that includes: a power transmitting device that includes a power transmitting unit, a power supply unit supplying electric power to the power transmitting unit and a matching transformer coupled between the power supply unit and the power transmitting unit and including a variable inductor and a variable capacitor that adjust an impedance of the power transmitting device; and a power receiving device that includes a power receiving unit carrying out electromagnetic resonance with the power transmitting unit to contactlessly receive electric power from the power transmitting unit, before starting transfer of electric power from the power transmitting device to the power receiving device, the variable inductor is adjusted on the basis of an impedance of the power receiving device to thereby bring the impedance of the power transmitting device close to the impedance of the power receiving device.

Abstract: A primary coil, a primary resonance coil, a secondary resonance coil, a secondary coil, and a load form a resonant system. A frequency matching section is configured to match the resonant frequency of a resonant system and the output frequency of a high frequency power source with each other when the load fluctuates. An impedance matching section is configured to match the impedance from input terminals of the primary coil to the load at the resonant frequency and the impedance from the high frequency power source to the input terminals of the primary coil with each other.

Abstract: A charging system for charging a vehicle battery using a commercial power supply available in a construction on the ground includes a charge device, a power line, a time setting unit, and a control unit. The charge device mounted on a vehicle charges the vehicle battery. The power line connects between the construction on the ground and the vehicle. The time setting unit sets a charge start time for starting battery charging. The control unit is used for starting battery charging at the charge start time.

Abstract: Provided is a parking assistance apparatus utilizing a fixed target by taking an image thereof, the parking assistance apparatus being capable of recognizing the fixed target with high recognition accuracy while using simple image recognition processing. A mark (M) includes a plurality of illuminators (1). Sets of the plurality of illuminators (1) form characteristic points C1 to C4. Turn-ON request generation means (36) of a vehicle-side device (20) sequentially generates turn-ON requests for each characteristic point and transmits the generated turn-ON requests to a parking-lot-side device (10). A display control unit (11) of the parking-lot-side device (10) turns ON the characteristic points based on the turn-ON requests. An image recognition unit (31) of the vehicle-side device (20) performs image recognition for the characteristic points sequentially.

Abstract: A charging system for charging a vehicle battery using a commercial power supply available in a construction on the ground includes a charge device, a power line, a time setting unit, and a control unit. The charge device mounted on a vehicle charges the vehicle battery. The power line connects between the construction on the ground and the vehicle. The time setting unit sets a charge start time for starting battery charging. The control unit is used for starting battery charging at the charge start time.

Abstract: It is an object of the present invention to provide a variable gain amplifier circuit operable with a low power supply voltage and with less noise generated inside the circuit. In the variable gain amplifier circuit, a third MOS transistor is connected between the respective sources of two MOS transistors constituting a differential amplifier circuit and to the gate of the third MOS transistor, and a DC bias voltage for operating the third MOS transistor in a non-saturated region is supplied. If the output voltage of an AM intermediate frequency variable gain amplifier circuit increases, a control voltage for reducing the resistance between the source and drain of the third MOS transistor is applied to reduce the gain of the AM intermediate frequency variable gain amplifier circuit.

Abstract: It is an object of the present invention to provide a variable gain amplifier circuit operable with a low power supply voltage and with less noise generated inside the circuit. In the variable gain amplifier circuit, a third MOS transistor is connected between the respective sources of two MOS transistors constituting a differential amplifier circuit and to the gate of the third MOS transistor, and a DC bias voltage for operating the third MOS transistor in a non-saturated region is supplied. If the output voltage of an AM intermediate frequency variable gain amplifier circuit increases, a control voltage for reducing the resistance between the source and drain of the third MOS transistor is applied to reduce the gain of the AM intermediate frequency variable gain amplifier circuit.

Abstract: A receiver of double conversion system wherein unwanted components included in received signals can be removed without fail and wherein the number of constituent parts has been reduced. The receiver comprises an antenna tuning circuit 10 including a tuning coil 11 and a variable-capacitance diode 13; a high frequency amplification circuit 20 for performing a high frequency amplification of a signal outputted by the antenna tuning circuit 10; two-stage mixing circuits 22, 28 for performing two frequency conversions of an output from the high frequency amplification circuit 20; and a detecting circuit 36 for detecting an output from the latter-stage mixing circuit 28.

Abstract: A receiver and its adjustment system and method that can reduce the effort and the cost required to give good characteristics. The receiver comprises a quadrature detector whose characteristics value is varied by adjusting the capacitance. The quadrature detector comprises a variable capacitance circuit 182 formed on a semiconductor substrate and an LC parallel resonance circuit 20 comprising an inductor 120 and a capacitor 122 formed outside the semiconductor substrate. The characteristic value of the quadrature detector is adjusted by varying the capacitance of the variable capacitance circuit 182.

Abstract: A receiver of double conversion system wherein unwanted components included in received signals can be removed without fail and wherein the number of constituent parts has been reduced. The receiver comprises an antenna tuning circuit 10 including a tuning coil 11 and a variable-capacitance diode 13; a high frequency amplification circuit 20 for performing a high frequency amplification of a signal outputted by the antenna tuning circuit 10; two-stage mixing circuits 22, 28 for performing two frequency conversions of an output from the high frequency amplification circuit 20; and a detecting circuit 36 for detecting an output from the latter-stage mixing circuit 28.