Hitachi, Ltd.

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Hitachi Metals, Ltd.

Hitachi Computer Peripherals Co., Ltd.

Hitachi Haramachi Semi-conductor, Ltd.

Renesas Technology Corp.

Hitachi Maxell, Limited

Hitachi Microcomputer System, Ltd.

Hitachi Maxwell, Ltd.

Hitachi Video and Information System, Inc.

Kenichi Onda

Akihiko Kanouda

Norikazu Tokunaga

Hideki Miyazaki

Yasuo Matsuda

Ryouhei Saga

Takeshi Onaka

Hiroshi Kimura

Katsunori Hayashi

Satoru Masuyama

Hideaki Horie

Kojin Abe

Mutsuhiro Mori

Naoki Sakurai

Masayoshi Sato

Hisao Amano

Hideo Sato

Kazuo Kato

Yutaka Suzuki

Takashi Sase

Kozo Watanabe

Morinobu Endo

Shin Kimura

Masato Isogai

Tomoyuki Tanaka

Kouzou Watanabe

Hidetoshi Arakawa

Ichiro Ikushima

Syuya Hagiwara

Kohei Yabuno

Mikiya Nohara

Nobuyuki Aihara

Shigekazu Zemba

Hiroshi Fukui

Ryotaro Kudo

Takashi Ikimi

Kiyoshi Sakamoto

Kunio Seki

Shin Nakajima

Hiroyuki Aoyama

Soichiro Ogawa

Yasumichi Yasuda

Kyoichi Hosokawa

Hidefumi Shirahama

Kenji Kawabata

Ikuo Yamato

Shinichi Yoshida

Masahiro Tobise

Noriyuki Uchiyama

Yuzo Morita

Motohiro Sugino

Takao Yaginuma

Yasunori Iwafuji

Masayuki Wada

Sadamu Saito

Yoichi Uehara

Ryuichi Ikeda

Toshiki Kurosu

Hirotaka Mochizuki

Sadaji Tashiro

Kozin Abe

Ryohei Saga

Noboru Ogawa

Makoto Goto

Takeshi Uemura

Tsugio Ogawa

Hideo Yoshinaka

Kouichi Mizuta

Akihoko Kanouda

Susumu Iijima

Yasuo Abe

The present invention reduces the capacity of the AC-DC converter for the peak load and realizes low price and reduction in the volume of the power unit. The apparatus built-in backup power supply has the peak cut function for sharing a part of the load current at the time of peak load from the secondary battery. The two-way DC-DC converterand the secondary batteryare installed on the DC output side of the AC-DC converterand a current larger than a predetermined peak cut level is discharged from the secondary batteryat the time of peak load. Further, when the load is less than the predetermined cut level, the secondary batteryis charged from the AC-DC convertervia the two-way DC-DC converter. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.

Backup power supply

It is aimed at decreasing losses not only in a synchronous rectifier circuit provided at a secondary side of a DC-DC converter, but also in a full-bridge switching circuit provided at a primary side thereof. The DC-DC converter comprises a transformer for voltage conversion, a synchronous rectifier circuit at the secondary side, and a full-bridge switching circuit at the primary side. The DC-DC converter performs synchronous rectifier control which uses switch transistors to change paths of currents flowing through the secondary coil in synchronization with switching operations at the primary side. The DC-DC converter detects currents flowing through a load at the secondary side, primary-side currents varying with the load currents, or primary-side input voltages to dynamically control off-timings of a synchronous rectification transistor at the secondary side. In addition, the DC-DC converter detects primary-side input voltages and currents flowing through the secondary-side load to dynamically control on-timings of a transistor in the primary-side switching circuit.

Switching power supply device and the semiconductor integrated circuit for power supply control

A power supply provided with: an AC/DC converter which receives AC power, converts the AC power into DC power, and outputs the DC power; a DC/DC converter which receives the DC power from the AC/DC converter, and controls a level of an output voltage of the DC/DC converter to be equal to a level of a voltage to be used by a load while the DC/DC converter supplies the output voltage to the load; a DC converter which is connected to an input of the DC/DC converter; and a DC power storage means which supplies electric power to the DC/DC converter through the DC converter.

Power supply with uninterruptible function

Apparatus built-in backup power supply system has a 'peak cut' function for sharing a part of the load current at the time of a peak load using a secondary battery. For this purpose, a two-way DC&#x2014;DC converterand the secondary batteryare installed on the DC output side of the AC-DC converterand that portion of the load current that exceeds a predetermined peak cut level is discharged from the secondary batteryduring peak loading. When the load is less than the predetermined cut level, the secondary batteryis charged from the AC-DC convertervia the two-way DC&#x2014;DC converterA suitable peak cut level is determined according to the state of charge of the secondary battery and load pattern, and is changed dynamically.

A power supply provided with: an AC/DC converter which receives AC power, converts the AC power into DC power, and outputs the DC power; a DC/DC converter which receives the DC power from the AC/DC converter, and controls a level of an output voltage of the DC/DC converter to be equal to a level of a voltage to be used by a load while the DC/DC converter supplies the output voltage to the load; a DC converter which is connected to an input of the DC/DC converter; and a DC power storage device which supplies electric power to the DC/DC converter through the DC converter.

A DC power supply device comprises an AC/DC converter , a DC/DC converter , and a DC converter 3 converting DC power from a battery to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit which observes a charging control level and a load sharing level, impresses a charging command on a UPS controlling part controlling the DC converter, and simultaneously provides a PFC controlling part controlling the AC/DC converter with a current command when a voltage level is less than the charging control level, stops only the charging command when the voltage level is more than the charging level and less than the load sharing level, and provides the UPS controlling part and the PFC controlling part with current commands when the voltage level is more than the load sharing level. The AC/DC converter and the DC converter supply power in parallel when a load is more than a prescribed value, and the DC converter supplies power as a backup when a trouble is present in an AC power input.

DC power supply device

A DC-DC converter is provided with a calculation circuit which estimates current flowing through a reactor in a control circuit for controlling a switching element and a circulation use element, and the switching element and the circulation use element are controlled by making use of the calculated reactor current value. Thereby, a DC-DC converter which operates in a high efficiency and with low ripple even during a light load condition and realizes a high response performance during load variation is provided.

Synchronized rectifier voltage step down DC-DC converter and control circuit therefor

A voltage regulator module includes a power supply circuit for supplying power to an integrated circuit, the power supply circuit including semiconductor switching devices and a drive circuit for driving the semiconductor switching devices; and charge storage means for smoothing an output of the power supply circuit, wherein charge storage unit having a smoothing capacitor includes an electric double-layer capacitor, wherein the electric double-layer capacitor includes a plurality of positive electrode terminals and a plurality of negative electrode terminals, and wherein the plurality of positive electrode terminals and the plurality of negative electrode terminals are disposed on a surface identical to a surface of the electric double-layer capacitor.

Voltage regulator module for micro processor and CPO using a super capacitor

A voltage regulator module includes a power supply circuit for supplying power to an integrated circuit, the power supply circuit including semiconductor switching devices and a drive circuit for driving the semiconductor switching devices; and charge storage means for smoothing an output of the power supply circuit, wherein charge storage unit having a smoothing capacitor includes an electric double-layer capacitor, wherein the electric double-layer capacitor includes a plurality of positive electrodes terminals and a plurality of negative electrode terminals, and wherein the plurality of positive electrode terminals and the plurality of negative electrode terminals are disposed on a surface identical to a surface of the electric double-layer capacitor.

DC-DC step-down converter with super capacitor

A DC power supply device comprises an AC/DC converter , a DC/DC converter , and a DC converter converting DC power from a battery to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit which observes a charging control level and a load sharing level, impresses a charging command on a UPS controlling part controlling the DC converter, and simultaneously provides a PFC controlling part controlling the AC/DC converter with a current command when a voltage level is less than the charging control level, stops only the charging command when the voltage level is more than the charging level and less than the load sharing level, and provides the UPS controlling part and the PFC controlling part with current commands when the voltage level is more than the load sharing level. The AC/DC converter and the DC converter supply power in parallel when a load is more than a prescribed value, and the DC converter supplies power as a backup when a trouble is present in an AC power input.

A direct-current power-supply apparatus provided by the present invention comprises a switching converter for converting an input direct-current power into another direct-current power, a control circuit and an isolation means. The switching converter has a main switch device for generating a pulse voltage from the direct-current input, a synchronous-rectification circuit on the output side of the switching converter and a reverse-current-blocking switch. On the other hand, the control circuit includes a PWM formation unit for driving the main switch device, a synchronous-rectification control unit for controlling an operation to drive the synchronous-rectification circuit and a driving control unit for controlling an operation to drive the reverse-current-blocking switch. The control circuit operates by using a common electric potential appearing on the output side of the switching converter as a reference electric potential. A driving signal is applied to the main switch device through the isolation means. Thus, the direct-current power-supply apparatus is controlled without need for exchanges of the signal for driving the main switch device and a signal isolated between control devices including a switch for synchronous rectification.

Direct-current power-supply apparatus, control circuit thereof and semiconductor integrated circuit device for power supply

In a voltage drop chopper type DC-DC converter, in an intermediate load area, a pulse train having a low peak value in the neighborhood of the threshold voltage is applied to a power MOSFET, whereby the power MOSFET is given a high ON resistance and turned on. By doing so, the output voltage is controlled by a PAM (pulse amplitude modulation) switch system for reducing the peak value below the supply voltage.

DC-DC converter with switchable control mode

A power supply apparatus includes a semiconductor switching device for outputting power and a control circuit for controlling the on/off operation of the semiconductor switching device. The control circuit includes a circuit for applying, when turning on the semiconductor switching device, a first control signal corresponding to the difference between the output voltage of the power supply apparatus and a first reference value to the semiconductor switching device in accordance with the increase in the output voltage from the power supply apparatus thereby to operate the semiconductor switching device in a non-saturated area, so that the semiconductor switching device is turned on gradually.

Method of driving semiconductor switching device in non-saturated state and power supply apparatus containing such a switching device

In order to provide a power inverter device which can reduce surge voltages in all of the operating conditions thereof and has a simple structure, in a neutral point clamped 3 level type power inverter device formed by connecting semiconductor switching elements, diodes and smoothing use capacitors connected via plate shaped conductors, a first plate shaped conductor connects the diodes and the smoothing use capacitors and a plurality of plate shaped conductors connecting the elements are disposed over the first plate shaped conductor and separated from it by an insulating material.

Power inverter device

The invention relates to a power supply system having plural converters connected in parallel. The current of each of the plural converters is detected and each of the converters is controlled so as to match each of the converters to a maximum current value from among the detected current values. In the parallel converters, when one or more converter fails, having an output current of zero, the remaining converters are each partially charged equally to maintain the load current. Since a common bus is arranged between plural converters and plural loads, it is possible to carry out a redundant operation having a high reliability. Since a stable output can be obtained without being affected by the failed converter, a power supply system having the redundancy and the high reliability can be attained.

Power supply system for supplying electric power to a load through

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Hitachi, Japan

Kenichi Onda