Fujitsu Corporation

Yale University

Fdk Corporation

Yoshiyasu Nakashima

Yu Yonezawa

Satoshi Kazama

Hiroshi Nakao

Koichi Yokota

Takahiko Sugawara

Isamu Yamada

Tomotake Sasaki

Takehiko Hayashi

Takao Goto

Hiroshi Yamada

Yasushi Hara

Yuki Tamura

Masatoshi Ishii

Yutaka Igarashi

Shinichi Shiotsu

Takaki Shimura

Akira Shiba

Hideyuki Motoyama

Masatomo Yasaki

Tsugito Maruyama

Hideki Tanaka

Yoshikatsu Ishizuki

Atsushi Yamaguchi

Shinya Sasaki

Kenji Kawabe

Hajime Hayashi

Toshiya Miyazaki

Shinya Iijima

Hideki Takauchi

Junji Kaneko

Shinichi Yoshimoto

Norio Fujimaki

Kazunori Hayami

Shigehiro Idani

Seiki Shibata

Hisato Hosoyama

Jun Oikawa

Kohtaro Gotoh

Roman B Kuc

Yoshinobu Matsui

Eiji Nagashima

Daiji Yamashita

James J Szinger

A power-supply apparatus includes a power-supply circuit to which an input voltage and an input current are input, to include a switching element to be controlled by a control signal so as to generate an output voltage and an output current, a memory, and a processor coupled to the memory and the processor to calculate a first duty ratio of the control signal so that the output voltage approaches a target voltage, calculate a second duty ratio of the control signal for the switching element, based on the input voltage, the input current, the output voltage, and the output current, detect deterioration of the power-supply circuit, based on the first duty ratio and the second duty ratio, generate the control signal of the first duty ratio when the power-supply circuit has not deteriorated, and generate the control signal for stopping the power-supply circuit when the power-supply circuit has deteriorated.

Power-supply apparatus and power-supply method

An electrolytic system includes, a power generator that outputs a first DC power, a plurality of converters each of which converts the first DC power into a second DC power according to a target duty ratio, and outputs voltage information and current information of the second DC power, a plurality of electrolyzers each of which receives the second DC power output from each of the plurality of converters and generates a gas, a control circuit that outputs control information by which the first DC power approaches a maximum power, based on a voltage value and a current value of the first DC power, and a selection circuit that outputs the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information and the voltage information and the current information.

Electrolytic system, electrolytic control circuit, and control method for electrolytic system

A current detection circuit included in a power supply detects a current flowing to an inductance element from a detection tap of an inductance element connected between an output terminal and an output of a first switching element. A control circuit included in the power supply controls a first control terminal of the first switching element and a second control terminal of a second switching element and calculates an output current flowing to a load based on the current detected by the current detection circuit.

Power supply and control method for power supply

A capacitor life diagnosis apparatus includes ringing detection circuitry that detects ringing of an output voltage of a power source including a capacitor at an output end, and signal generation circuitry that generates a signal indicating a life of the capacitor based on the ringing detected by the ringing detection circuitry.

Capacitor life diagnosis apparatus and capacitor life diagnosis method

An electronic apparatus includes a housing; a substrate disposed on the inner side of the housing; a plurality of temperature sensors disposed on the substrate; and a processor. The processor performs a procedure including calculating heat source temperatures of a plurality of heat sources disposed on the substrate from temperatures measured by the temperature sensors by using a first heat transfer model not including a first parameter representing a transient response of heat transfer from the heat sources to the temperature sensors; and calculating a surface temperature of a surface of the housing from the heat source temperatures by using a second heat transfer model including the first parameter and a second parameter representing a transient response of heat transfer from the heat sources to the surface.

Electronic apparatus and surface temperature calculation method

A capacitor life diagnosis device includes: a first fluctuation detecting unit configured to detect a maximum value of fluctuation in output voltage of a first capacitor every fixed time; and an output unit configured to predict a residual life of the first capacitor on the basis of temporal transition of the maximum value of fluctuation in the output voltage detected by the first fluctuation detecting unit, and output a signal indicating the residual life of the first capacitor.

Capacitor life diagnosis device, capacitor life diagnosis method, and program

A processor disposed over a substrate of an electronic apparatus acquires a first measured value from a temperature sensor disposed on the substrate, and calculates surface temperature of a surface of an enclosure of the electronic apparatus on the basis of a transfer function G(s) based on a first thermal resistance and a first thermal capacitance between a heat source over the substrate and the surface of the enclosure, a transfer function H(s) based on a second thermal resistance and a second thermal capacitance between the heat source and the temperature sensor, and the first measured value.

Enclosure surface temperature estimation method and electronic apparatus

A power supply device coupled to a load includes a first switch that switches a current input from an input terminal, a second switch that switches between a ground potential and an output of the first switch, an inductor that establishes a connection between an output terminal and the output of the first switch, a current sensing circuit that senses a peak current value serving as a peak value of a current flowing through the inductor, and a control circuit that controls a first control terminal of the first switch and a second control terminal of the second switch and that calculates a value of an output current flowing through the load, based on an output value of a temporal coefficient circuit coupled to one of a first control signal.

Power supply device, control circuit for power supply device, and control method for power supply device

A power supply device includes: a memory; and a processor coupled to the memory and the processor configured to: determine a duty ratio of a control signal of a switching element in a power supply circuit so that an output voltage of the power supply circuit approaches a target voltage; compute an acceptable range of a duty ratio based on an output current of the power supply circuit detected by a current detecting circuit; output the duty ratio when the duty ratio is inside the acceptable range; and stop the power supply circuit when the duty ratio is outside the acceptable range.

Power supply device and method for controlling power supply circuit

A power supply apparatus includes a trans circuit configured to convert an input voltage into an output voltage by adjusting switching of the input voltage; an output voltage detector configured to detect the output voltage; a compensator configured to generate a control value controlling a duty ratio of the switching such that a value of the detected output voltage coincides with a target value for the output voltage; an input voltage detector configured to detect the input voltage; an estimator configured to estimate an allowed range of the control value in accordance with the target value and a value of the detected input voltage; and an adjuster configured to adjust the control value so as to stop the switching when the control value falls outside the allowed range.

Power supply apparatus and error detecting method for power supply apparatus

A control method for a switching power supply circuit, the control method causing a processor to execute a process, the process includes: calculating a differential value between an output voltage of the switching power supply circuit and a target voltage; multiplying the differential value by a first coefficient to calculate a correction value; correcting a first detection value of an output current of the switching power supply circuit, which is detected by a current transformer circuit, based on the correction value, to generate a second detection value; comparing the second detection value with a threshold current value to determine whether or not an overcurrent has occurred; and reducing, when it is determined that the overcurrent has occurred, the output voltage of the switching power supply circuit.

Control method for switching power supply circuit and power supply device

A double-ended forward converter includes: a first switching element and a second switching element that are coupled to a primary side of a transformer; a pulse generation circuit that generates a pulse signal for controlling the first and second switching elements; an isolation transformer that converts the pulse signal into an alternating-current signal; a rectifier circuit that rectifies the alternating-current signal and generate gate voltages of the first and second switching elements; a driver circuit that includes a third switching element which drives gates of the first and second switching elements, a voltage generated on a secondary side of the isolation transformer being input to a gate of the third switching element; and a minus bias generation circuit that generates a source voltage of the third switching, based on a change in the voltage generated on the secondary side of the isolation transformer.

Double-ended forward converter and power supply device

An inductor apparatus includes: a substrate including an electrical insulation property and a non-magnetic material; and a plurality of inductors disposed in the substrate so as to extend from a first surface of the substrate to a second surface of the substrate, each of the plurality of inductors including: an inductor conductive part that has an electrical conductivity and extends in a thickness direction of the substrate; and a magnetic layer that covers a side of the inductor conductive part and include a relative permeability and a soft magnetic material.

Inductor apparatus and inductor apparatus manufacturing method

A control device includes a processor that executes a process including generating a driving signal that drives a switching device, so that an output voltage of a converter circuit that performs a step-down conversion on input power by driving the switching device matches a target value, and modifying the target value so that as an output current of the converter circuit becomes lower the output voltage becomes closer to an upper limit value of the output voltage.

Control device, DC-DC converter, switching power supply apparatus, and information processing apparatus

A semiconductor device includes: a first field-effect transistor configured to have a source connected to a reference potential node; a second field-effect transistor configured to have a source connected to a drain of the first field-effect transistor, and a gate connected to the source of the first field-effect transistor; a gate signal node configured to input a gate signal therein; a first resistor configured to be connected between the gate signal node and a gate of the first field-effect transistor; and a first capacitor and a switch circuit configured to be connected between a drain of the second field-effect transistor and the gate of the first field-effect transistor, in which the switch circuit is connected in series with the first capacitor.

Semiconductor device

Growing community of inventors

Kawasaki, Japan

Yoshiyasu Nakashima