Murata Manufacturing Co., Ltd.

Shinji Goma

Keiichi Ichikawa

Kazuya Kato

Tsuyoshi Suesada

Henri Bondar

Tatsuo Bizen

Noboru Kato

Nobuhito Tsubaki

Tsutomu Ieki

Takeshi Kataya

Teruaki Oshita

Masao Uno

Yoshiyuki Mashimo

Miyako Kabumoto

A power conversion device includes a step-down-type transformer and a bridge circuit that rectifies output voltage of the transformer and supplies the rectified output voltage to a load. The bridge circuit is connected to a secondary winding of the transformer and includes MOS-FETs connected in series and diodes connected in series. A gate of the MOS-FET is connected to one end of a primary winding of the transformer with a capacitor interposed therebetween and a gate of the MOS-FET is connected to the other end of the primary winding of the transformer with a capacitor interposed therebetween. With this, a power conversion device and a wireless power transmission system that can achieve space saving and reduce loss in a rectifying element are provided.

Power conversion device and wireless power transmission system

An inspecting apparatus is for a noncontact power transfer system that transfers electric power from a transmitting unit to a receiving device in a noncontact manner. The inspecting apparatus includes a coupling capacitance varying unit configured to vary at least one of a first coupling capacitance formed between a transmitting-side passive electrode and a receiving-side passive electrode and a second coupling capacitance formed between a transmitting-side active electrode and a receiving-side active electrode when the receiving device is placed on the transmitting unit, and a control unit configured to monitor an alternating-current voltage generated between the receiving-side passive electrode and the receiving-side active electrode of the receiving device or a direct-current voltage obtained through conversion by a rectifying circuit.

Inspecting apparatus and inspecting method for noncontact power transfer system

A wireless power receiver device includes a sheet-like electrode sheet section and a power receiver section. The electrode sheet section includes a power receiver side active electrode and a power receiver side passive electrode that are substantially coplanar and formed into sheet-like shapes; lead lines that are coplanar with both the electrodes, extended from the respective electrodes, and formed into sheet-like shapes; and an insulation sheet that covers both the electrodes and both the lead lines from both sides thereof. The power receiver section includes a step-down unit that steps down an alternating-current voltage induced between end portions of the lead lines; a power receiver module that rectifies and smoothes the alternating-current voltage that is stepped down by the step-down unit; and a connector for outputting an output voltage of the power receiver module.

Wireless power receiver device, wireless power transmitter device, and wireless power transceiver device

A power transmission-side measurement tool is installed in a power transmitting apparatus that applies an AC voltage stepped up by a step-up transformer to an active electrode and a passive electrode. The power transmission-side measurement tool includes a measurement active electrode that faces the active electrode and a measurement passive electrode that faces the passive electrode, and the measurement active electrode and measurement passive electrode are shorted together. Frequency characteristics of a serial resonance circuit formed by leakage inductance of the step-up transformer and capacitors are measured in a state where the power transmission-side measurement tool is placed on the power transmitting apparatus.

Frequency characteristic measurement method

A power transmission system includes a charging station and a power receiving device. The charging station has a pair of first electrodes, and a signal source that emits an alternating current signal; and a step-up transformer that applies a stepped-up voltage to the pair of first electrodes. The power receiving device has a pair of second electrodes opposite to and that capacitively couple with the first electrodes; a step-down transformer; a rectifying and smoothing circuit that rectifies and smoothes the stepped-down AC voltage; and a load circuit, The charging station further has a potential stabilizing electrode that capacitively couples with the electrode connected to a reference potential of the power receiving device and the potential stabilizing electrode is connected to a reference potential of the charging station via a charge controller.

Power transmission system

A capacitance (Cp) is a capacitance formed between a transmitting-device-side passive electrode and a receiving-device-side passive electrode. A capacitance (Ca) is a capacitance formed between a transmitting-device-side active electrode and a receiving-device-side active electrode. A bridge circuit formed by Zto Zis connected to a secondary side of a step-up transformer, where Zrepresents an impedance of a first element, Zrepresents an impedance of a second element, Zrepresents an impedance of a series circuit formed by the capacitance (Ca) and a load, and Zrepresents an impedance of the capacitance (Cp). By determining the impedances Zto Zsuch that this bridge circuit is balanced, a potential at a receiving-device-side reference potential point is made equal to a ground potential. This reduces variation in receiving-device-side reference potential, reduces noise, and stabilizes the operation of a load circuit on the receiving device side.

Power transfer system

An active electrode and a passive electrode are electrically field-coupled with an active electrode and a passive electrode provided in a power transmission device, respectively. Power in a high frequency voltage excited on the active electrode and the passive electrode is supplied to a mobile unit via a step-down transformer, a rectification smoothing circuit, and a DC-DC converter. A CPU turns off switches when wireless communication is carried out. The passive electrode functions as a booster antenna that is magnetically field-coupled with an antenna coil. A high frequency signal outputted from an RF circuit is transmitted via the antenna coil and the passive electrode, and a high frequency signal transmitted from the power transmission circuit is inputted, via the passive electrode and the antenna coil, to the RF circuit.

Power reception device, power transmission device, and power transmission system

A power transmitting apparatus includes a power transmitting apparatus side passive electrode and a power transmitting apparatus side active electrode, and a power receiving apparatus includes a power receiving apparatus side active electrode and a power receiving apparatus side active electrode. The power transmitting apparatus side active electrode and the power transmitting apparatus side passive electrode are not parallel with each other in terms of a positional relationship, and the power receiving apparatus side active electrode and the power receiving apparatus side passive electrode are not parallel with each other in terms of a positional relationship. By mounting the power receiving apparatus on the power transmitting apparatus, the power transmitting apparatus side passive electrode and active electrode respectively face the power receiving apparatus side passive electrode and active electrode.

Power transmitting apparatus, power receiving apparatus, and wireless power transmission system

A power transmitting apparatus has a power transmitting apparatus side active electrode provided within the casing thereof along a seat. A power transmitting apparatus side passive electrode is exposed on a backrest. A power receiving apparatus has a power receiving apparatus side active electrode formed along the bottom surface thereof. A power receiving apparatus side passive electrode is formed on the outer surface of the casing of the power receiving apparatus. By mounting the power receiving apparatus on a mounting portion of the power transmitting apparatus, the power receiving apparatus side active electrode faces the power transmitting apparatus side active electrode with a dielectric layer therebetween, and the power receiving apparatus side passive electrode is directly electrically connected to the power transmitting apparatus side passive electrode.

Power transmitting apparatus, power receiving apparatus, and power transmission system

A thin and compact battery module capable of suppressing an increase in temperature of the battery in the battery module when the battery is charged. The battery moduleincludes a power circuithaving a heat-generating multilayer inductorA, a resin layerin which the power circuitis embedded, and a secondary cell arranged on the top face of the resin layer. The resin layerhas multiple recessesA in a portion that is in contact with the secondary cell

Battery module and charging module

A miniaturized oscillator that is manufactured with greatly reduced production time and cost includes transmission lines defining resonance circuits provided on a circuit assembly board. In this state, the impedance of each transmission line is measured. Then, according to the transmission line impedance, chip components having impedances necessary to obtain a predetermined frequency are selected and mounted on the circuit substrate. With this arrangement and method of formation, the resulting oscillator oscillates at the desired oscillation frequency and it is not necessary to trim the transmission lines in order to achieve this result. Since the oscillator does not require time to make frequency adjustments and does require use of a trimming apparatus, no deterioration in the electric characteristics due to laser trimming occurs. In addition, it is unnecessary to provide an electrode land for making frequency adjustments. As a result, the entire oscillator is miniaturized.

Oscillator, method for producing oscillator, and communication apparatus incorporating same

A voltage-controlled oscillator has a frequency of oscillation that is varied using a substrate on which the same circuit pattern as that of the voltage-controlled oscillator is printed. In a resonant circuit included in the voltage-controlled oscillator, a first land is arranged substantially parallel to an inductor. A second land is arranged substantially parallel to the inductor and to a variable-capacitance diode. The capacitances of capacitors attached to the first land and second land are changed in order to vary the frequency of oscillation of the voltage-controlled oscillator. The frequency of oscillation can be varied without the necessity of scraping the inductor through which a major signal passes. Therefore, electrical characteristics of the voltage-controlled oscillator are not degraded and the frequency of oscillation is very steady. The frequency of oscillation can be varied merely by changing the capacitances of the capacitors attached to the first and second lands. Consequently, a step of scraping a strip line can be excluded, and manufacturing efficiency can be improved.

Voltage-controlled oscillator and electronic device using same

An input change-over amplifier is capable of effecting a change-over in outputting two signals having different frequencies, without lowering the signal levels thereof. Two signals having different frequencies are fed into two input terminals of an amplifying element. When a signal is input through one input terminal, the other input terminal is grounded. When a signal is input through the other input terminal, the above one input terminal is grounded. In this way, it is possible to effect a change-over in outputting two signals having different frequencies, without lowering the signal levels thereof. Further, since two signals can be fed into an amplifying element through different paths, it is not necessary to provide a matching circuit at a connection point of signal paths. Therefore, the number of required electronic parts can be reduced, an oscillator which is compact in size can be manufactured, and a necessary circuit can be designed within only a short time.

Input change-over type amplifier and frequency change-over type oscillator using the same

A voltage controlled oscillation circuit includes a resonance circuit and an oscillation circuit. The oscillation circuit includes a capacitor, a variable capacitance diode, and a resonator composed of a strip line one end of which is grounded. The oscillation circuit includes an oscillation transistor, bias resistors, and, a Colpitts capacitor, a harmonic bypass capacitor, and a chip capacitor, one end of which is connected in series with a resistor and the other end of which is grounded. A node between the bias resistor and the chip capacitor connects the resonator composed of a strip line provided within the resonance circuit via a connection line, whereby the emitter of the oscillation transistor provided within the resonance circuit is grounded via the bias resistor and the resonator. In addition, a parallel resonance circuit is composed of the resonator and the chip capacitor.

Voltage controlled oscillator with a resonator common to a resonance

A resonance inductor of a resonant circuit is formed of a chip inductor and an inductance fine adjustment pattern. A resonance capacitor is formed of a plurality of chip layered capacitors connected in parallel to each other via connection patterns formed on a substrate. The connection patterns are sequentially disconnected to adjust the capacitance of the resonance capacitor. Then, the inductance fine adjustment pattern is partially removed to adjust the inductance of the resonance inductor.

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Nagaokakyo, Japan

Shinji Goma