Murata Manufacturing Co., Ltd.

Henri Bondar

Keiichi Ichikawa

Patrick Camurati

Tsuyoshi Suesada

Shinji Goma

Hironobu Takahashi

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

A power transfer system that transfers electric power from a power transmission device to a power reception device through electrical coupling. The power transmission device and the power reception device structurally designed such that the power transfer system is able to stabilize reference potentials of the power transmission device and the power reception device when the power reception device is placed on the power transmission device.

Power transfer system with capacitive coupling

A power transmission system is disclosed in which power is transmitted from a power transmission apparatus to a power receiving apparatus by electric field coupling between active and passive electrodes. The power transmission apparatus includes a step-up/down circuit for stepping up or down a direct voltage and an inverter circuit for converting the direct voltage into an alternating voltage that is output to the active and passive electrodes. The power transmission apparatus controls the step-up/down circuit to sweep a transformation ratio M=Vo/Vin and detects the ratio M when an input power Pin of the step-up/down circuit is a minimum. The power transmission apparatus drives the step-up/down circuit to obtain the ratio M and perform the power transmission. As a result, there is provided a power transmission system capable of efficiently performing power transmission regardless of the change in a load in the power receiving apparatus.

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

The frequency generated by a high-frequency high-voltage generator is set to a higher one of the frequencies of two coupled modes which take place when a resonance circuit of a power transmission device and that of a power reception device are coupled to each other. For this reason, charge generated on an active electrode of the power transmission device and that generated on an active electrode of the power reception device have the same polarity, while an electric potential of a passive electrode of the power transmission device and that of a passive electrode of the power reception device have the same polarity. When the passive electrode of the power transmission device is connected to the ground, the electric potential of the passive electrode is zero V. Therefore, the electric potential of the passive electrode of the power reception device is substantially zero V.

A power transfer system includes a power transmission device and a power reception device. A central conductor and a peripheral conductor are formed near the upper surface of a casing of the power transmission device. The peripheral conductor surrounds the central conductor in an insulated state from the central conductor. An alternating voltage generating circuit is provided for the power transmission device and applies an alternating voltage between the central conductor and the peripheral conductor. A central conductor and a peripheral conductor are formed near the lower surface of a casing of the power reception device. The peripheral conductor surrounds the central conductor in an insulated state from the central conductor. A load circuit is provided for the power reception device, and a voltage induced between the central conductor and the peripheral conductor is applied to the load circuit.

Power transfer system and noncontact charging device

A power transfer system includes a power transmission device and a power reception device which are capacitively coupled to allow electrical conduction therethrough in the manner of alternating current. The power transmission device includes an active electrode, a passive electrode, a step-up transformer, and a high-frequency voltage generating circuit. The power reception device includes an active electrode, a passive electrode, and a load circuit. A divider for voltage division based on load capacitances (Cand C) is provided between the active electrode and the passive electrode. The active electrode and the passive electrode have respective equivalent capacitances to ground (Ca and Cp) relative to the ground potential. A ground leakage current Ig is minimized by adjusting the values of the respective capacitances in an equivalent circuit so as to satisfy the relationship: C/C=Cp/Ca.

High-frequency power device, power transmission device, and power transfer system

A power reception device and a power transmission device which are capable of suppressing an adverse effect of an electric field. A power reception device includes a capacitive coupling electrode comprising a high voltage side conductor and a low voltage side conductor extending around the high voltage side conductor. The high voltage side conductor is disposed on a surface of a housing. The low voltage side conductor is disposed inside a circuit board. A plurality of module parts are mounted on a surface of the circuit board which is located on an opposite side away from the high voltage side conductor with respect to the low voltage side conductor.

Power reception device and power transmission device

A power transmission device that includes a high-frequency high-voltage generating circuit which applies a high voltage of high frequency between a power transmission device side active electrode and a power transmission device side passive electrode, the power transmission device side passive electrode being disposed in a manner to surround the power transmission device side active electrode and the high-frequency high-voltage generating circuit. An auxiliary high-frequency high-voltage generating circuit is provided between a ground of the power transmission device having a potential substantially equal to the ground potential and the power transmission device side passive electrode. The auxiliary high-frequency high-voltage generating circuit suppresses a potential change of the power reception device side passive electrode relative to the ground potential.

Power transmission device and power transfer system

A power transmission system that includes a power transmitting device and a power receiving device. The power transmitting device includes a high-frequency voltage generator, a piezoelectric resonator, a power transmitting device side passive electrode, and a power transmitting device side active electrode. The power receiving device includes a piezoelectric resonator, a load, a power receiving device side passive electrode, and a power receiving device side active electrode. The active electrode of the power transmitting device and the active electrode of the power receiving device are in proximity with each other, whereby the power transmitting device and the power receiving device are capacitively coupled through the active electrodes and the surrounding dielectric medium.

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

A high-voltage side conductor is formed near the upper surface of a power transmission device, and a low-voltage side conductor is formed near the lower surface of the power transmission device. The power transmission device includes an alternating voltage generating circuit. A high-voltage side conductor is formed near the lower surface of a power reception device, and a low-voltage side conductor is formed near the upper surface of the power reception device. The power reception device includes a load circuit. When the high-voltage side conductors face a capacitive coupling conductor of an auxiliary sheet, capacitances are generated respectively between the high-voltage side conductors and the capacitive coupling conductor. Thus, the high-voltage side conductors are capacitively coupled to each other via the capacitive coupling conductor.

A power transfer system includes a power transmission device, a power reception device and a capacitive coupling conductor. A high-voltage side conductor is formed near the upper surface of a casing of the power transmission device, and a low-voltage side conductor is formed near the lower or surrounding surface of the casing. The power transmission device includes an alternating voltage generating circuit. A high-voltage side conductor is formed near the lower surface of a casing of the power reception device, and a low-voltage side conductor is formed near the upper surface of the casing of the power reception device. The power reception device includes a load circuit. The high-voltage side conductors are capacitively coupled to each other when facing each other, and the low-voltage side conductors are capacitively coupled to each other via a capacitive coupling conductor.

The apparatus according to the invention is composed of one or plural generator devices () connected to an energy source and of one or plural loads () (which may be mobile). Each load is powered by the intermediary of a limited spatial zone () where an electric field that is intense and rapidly varying is present, and this is achieved without wires or electrical contact or use of an earth connection. The intense field is created locally between certain sub-electrodes () located on the surface of the generator and an electrode () or several sub-electrodes on the load side and located opposite. The active sub-electrodes () on the generator side are selected by switches (), for example magnetic switches activated by a permanent magnet () located at the load (). On the load side, a passive electrode () is used which can be considered as mainly coupled to the surrounding dielectric medium. The invention targets, in particular, the tele-supply of energy to low and medium power fixed or mobile electric devices.

Method and device for transporting, distributing and managing electrical energy by remote longitudinal coupling in near field between electric dipoles

The invention proposes a means for transporting electrical energy and/or information from a distance by using, at a slowly varying regime, the Coulomb field which surrounds any set of charged conductors. The device according to the invention is composed of energy production and consumption devices situated a short distance apart, it uses neither the propagation of electromagnetic waves nor induction and cannot be reduced to a simple arrangement of electrical capacitors. The device is modeled in the form of an interaction between oscillating asymmetric electric dipoles, consisting of a high-frequency high-voltage generator () or of a high-frequency high-voltage load () placed between two electrodes. The dipoles exert a mutual influence on one another. The devices according to the invention are suitable for powering industrial and domestic electrical apparatus, they are especially suitable for powering low-power devices moving in a limited environment and for short-distance non-radiating transmission of information.

Growing community of inventors

Kyoto, Japan

Henri Bondar