Denso Corporation

Toyohashi University of Technology

Takanari Sasaya

Tomonori Kimura

Takeshi Inoue

Takashi Kaneko

Shoichi Yamauchi

Jun Sakakibara

Takeshi Enya

Takashi Ohira

Masaki Matsui

Akiyoshi Asai

Nobuaki Kawahara

Hisashi Takasu

Kunihiro Onoda

Naoki Sakai

Michiru Takahashi

Hisayoshi Ohshima

Akihiro Yamaguchi

Tetsuo Hirano

Takaaki Masaki

In each E-class inverter, an internal voltage detection circuit detects an internal voltage of a resonant type power supply circuit or a matching circuit and adjusts a phase of a driving signal of a MOSFET based on a detected voltage. It is thus possible to match a phase of a current voltage of a sine waveform of each inverter and combine power highly efficiently. Since power combining is performed highly efficiently without using a variable capacitor and variable inductor, it is possible to suppress upsizing of elements and achieve downsizing of a power amplifier circuit.

Power amplifier circuit including multiple inverters connected in parallel

A driving circuit for a switching element includes a main current wiring and a substrate. The main current wiring has a flat surface and carries a main current. The substrate has a flat surface mounted on the flat surface of the main current wiring and includes a coil disposed inside. The coil is disposed so as to interlink with a magnetic flux generated depending on the main current of the switching element and is electrically connected such that the coil receives the pulse signal of the signal source and transmits the pulse signal to a control terminal of the switching element.

Drive circuit for switching element

In a power switching circuit, a second commutation member has a second commutation path electrically connected in parallel to a first commutation path and a second diode provided in the second commutation path and electrically connected antiparallel to a semiconductor switching element. While the semiconductor switching element is off, the second commutation path allows a second current based on the inductive load to flow therethrough in a forward direction of the second diode within a commutation period. The second diode has a second reverse recovery time shorter than a first reverse recovery time of the first diode. A second inductance of the second commutation path is higher than a first inductance of the first commutation path.

Power switching circuit improved to reduce loss due to reverse recovery current

A method for controlling a vertical type MOSFET in a bridge circuit is provided to reduce diode power loss and improve a reverse recovery characteristic. The method includes controlling a forward voltage of a built-in diode of the vertical type MOSFET to be a first forward voltage by setting a gate voltage of the vertical MOSFET to a first gate voltage, so that the vertical type MOSFET is switched into a first off mode; and controlling the forward voltage of the built-in diode of the vertical type MOSFET to be a second forward voltage by setting the gate voltage of the vertical MOSFET to a second gate voltage, so that the vertical type MOSFET is switched into a second off mode.

Method for controlling vertical type MOSFET in bridge circuit

A rotation information detection device detects rotation information of a DC motor based on a surge component waveform superimposed on a voltage waveform between the terminals of the DC motor or a current waveform of the DC motor, a circuit is provided which supplies a current of a current value I45% during motor forward rotation or I55% during reverse motor rotation to the motor over the period from when the motor starts braking operation to when it stops.

DC motor rotation information detecting device

Methods for manufacturing semiconductor substrates in which a semiconductor layer for forming semiconductor device therein is formed on a supporting substrate with an insulating film interposed between, with which in forming the semiconductor layer on a substrate on which a buried pattern structure has been formed it is possible to greatly increase the film thickness uniformity of the semiconductor layer and the film thickness controllability, particularly when the semiconductor layer is being formed as an extremely thin film. As a result, it is possible to achieve improved quality and characteristics of the semiconductor substrates and make possible the deployment of such semiconductor substrates to various uses.

Method for manufacturing a semiconductor substrate

A variable focus lens device having a temperature compensation function whose construction is simple and which can be inexpensively manufactured. The device has a lens member including a lens container having a transparent elastic film, a transparent sealing member forming an internal volume, and a transparent liquid filling the internal volume, a stack-type piezoelectric actuator for varying the focus of the lens member by deforming the transparent elastic film by fluctuating the pressure inside the internal volume, and a tank connected to the internal volume by narrow passages. The tank and the narrow passages absorb temperature fluctuation components of the transparent liquid, which varies due to thermal expansion and contraction. The tank and the passages thereby form a temperature compensator, that, because the passages are narrow, does not react to sudden oscillating pressure components caused by the stack-type piezoelectric actuator.

Variable focus lens device having temperature fluctuation compensating feature for lens device liquid

Growing community of inventors

Toyokawa, Japan

Takanari Sasaya