Omron Corporation

Chiba University

Shingo Nagaoka

Takeshi Uematsu

Taichi Mishima

Hiroyuki Onishi

Takeo Nishikawa

Hiroo Sekiya

Mitsuru Sato

Shigeru Aoyama

Toshiyuki Zaitsu

Kentaro Hamana

Tomohiko Matsushita

Yuki Ito

Yutaro Okuno

Tetsuichi Wazawa

Sadaharu Morishita

Hiroki Ishibashi

A resonance-type power converter circuit includes: a resonance circuit including a first LC resonance circuit and a switching element, and outputting an output voltage or current to a load; a detector circuit detecting output information; an calculation controller searching for a maximum point in a characteristic of the output information at an operating frequency based on the detected output information, and determining an operating frequency corresponding to the searched maximum point; and a signal generator generating a drive control signal having the determined operating frequency, and controlling the frequency based on the drive control signal. The resonance circuit has a characteristic of output information at the operating frequency having a load independent point not depending on the load and corresponding to the maximum point and feeds back a drive control signal including the output information to the switching element and drives it at the load independent point by frequency control.

Resonance-type power converter circuit provided with resonance circuit including LC resonance circuit and switching element

At a first node, an intermediate voltage potential occurs between a voltage potential of the first input terminal and a voltage potential of the second input terminal A second node is connected to ends of primary windings of transformers of LLC resonant converters. A switch circuit is connected between the first node and the second node. A control circuit is configured to turn on a switch circuit when a load current of a load apparatus connected to a first output terminal and a second output terminal is equal to or smaller than a predetermined criterion and turn off the switch circuit when the load current of the load apparatus is larger than the predetermined criterion.

Power conversion apparatus having multiple LLC converters and capable of achieving desired output voltage even in changes in load current

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.

Contactless power transmission system capable of controlling power transmitter apparatus to stably supply load device with required power

In a power converter apparatus including a PFC circuit operating in a current-critical mode, a zero point of an inductor current is accurately detected. The control circuit includes a current detector unit including a first detection circuit that detects an inductor current, amplifies a voltage corresponding to the detected current with a gain, and outputs it as a detection voltage and a comparison circuit that compares the detected voltage with a predetermined reference voltage and outputs a comparison result signal. The control circuit calculates the reference voltage for making a delay when detecting the zero value of the inductor current substantially zero, based on the detected input voltage, the detected output voltage, the preset delay time, the inductance value of the inductor, the conversion factor in current/voltage converting, the power supply voltage, and the gain, and then, outputs it to the comparison circuit.

Control circuit for power converter apparatus provided with PFC circuit operating in current-critical mode

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.

Contactless power transmission system for transmitting power from power transmitter apparatus to power receiver apparatus, and detecting foreign object

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.

Contactless power transmission system for transmitting power from power transmitter apparatus to power receiver apparatus, and supplying load device with desired voltage

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.

Resonance oscillator circuit and contactless power supply system

Provided is a transformer (), which includes: a core () which forms a magnetic circuit and has a middle leg () and a plurality of side legs () branched from the middle leg (); primary windings () respectively wound around a first winding leg () and a second winding leg (), which are selected from the middle leg () and the side legs (); and a secondary winding () wound around either of the first winding leg () or the second winding leg (), wherein a first magnetic flux generated by the primary windings () from the first winding leg () and a second magnetic flux generated by the primary windings () from the second winding leg () differ from each other by a predetermined value or more at a position at which the fluxes do not intersect with the secondary winding ().

Transformer and resonant circuit having same

The LLC resonant converter includes a bridge circuit configured to receive a DC input voltage, an LLC resonant circuit connected to the bridge circuit, a transformer connected to the LLC resonant circuit, a rectifier circuit connected to the transformer and configured to send out a converted DC voltage, a resonant capacitor changeover circuit, a bridge circuit control section, and a resonant capacitor changeover control section. When the input voltage exceeds a changeover voltage, the operating frequency is raised higher than the resonance frequency, and thereafter the switch is turned off.

LLC resonant converter

Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. A noise eliminator in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch) and the radiator (heatsink). A conductive member of the noise eliminator is connected to a stable potential.

Power converter

Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. A noise eliminator in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch) and the radiator (heatsink). A flexible connecting line connected to a conductive member of the noise eliminator is connected to an on-board line disposed on a circuit board.

The metal fine particlesare sparsely fixed on the surface of the transparent substrate, and the acceptorfor attaching the specific ligand is immobilized on the transparent substrateor the metal fine particles. The prismis closely attached to the lower surface of the transparent substrate, and the excitation light enters the transparent substratethrough the prism. The incident light is totally reflected at the surface of the transparent substrate, and the evanescent light generated at the surface and the metal fine particleslocally plasmon resonate. As the evanescent light and the metal fine particles locally plasmon resonate, a strong electric field is enclosed in the vicinity of the metal fine particles. When the surface arranged with the metal fine particlesand the acceptoris contacted to the analysis sample solution containing ligand modified with light emitting molecules, only the light emitting molecule modifying a specific ligand attached to the acceptor emits light.

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Kizugawa, Japan

Shingo Nagaoka