Patents by Inventor Ryouhei Saga

Ryouhei Saga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7157810
    Abstract: 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 converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3 and a current larger than a predetermined peak cut level is discharged from the secondary battery 4 at the time of peak load. Further, when the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC-DC converter 5. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.
    Type: Grant
    Filed: January 12, 2004
    Date of Patent: January 2, 2007
    Assignees: Hitachi, Ltd., Hitachi Maxell, Ltd., Hitachi Computer Peripherals Co., Ltd.
    Inventors: Akihiko Kanouda, Satoru Masuyama, Masato Isogai, Ryouhei Saga, Kenichi Onda, Norikazu Tokunaga
  • Patent number: 6977448
    Abstract: 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—DC converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3, and that portion of the load current that exceeds a predetermined peak cut level is discharged from the secondary battery 4 during peak loading. When the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC—DC converter 5. A suitable peak cut level is determined according to the state of charge of the secondary battery and load pattern, and is changed dynamically.
    Type: Grant
    Filed: April 28, 2003
    Date of Patent: December 20, 2005
    Assignees: Hitachi, Ltd., Hitachi Maxwell, Ltd., Hitachi Computer Peripherals Co., Ltd.
    Inventors: Akihiko Kanouda, Satoru Masuyama, Masato Isogai, Ryouhei Saga, Kenichi Onda, Norikazu Tokunaga
  • Publication number: 20040145926
    Abstract: 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 converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3 and a current larger than a predetermined peak cut level is discharged from the secondary battery 4 at the time of peak load. Further, when the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC-DC converter 5. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.
    Type: Application
    Filed: January 12, 2004
    Publication date: July 29, 2004
    Inventors: Akihiko Kanouda, Satoru Masuyama, Masato Isogai, Ryouhei Saga, Kenichi Onda, Norikazu Tokunaga
  • Patent number: 6643152
    Abstract: A DC power supply device comprises an AC/DC converter 1, a DC/DC converter 2, and a DC converter 3 converting DC power from a battery 4 to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit 100 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.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: November 4, 2003
    Assignees: Hitachi, Ltd., Hitachi Computer Peripherals Co., Ltd., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Norikazu Tokunaga, Kenichi Onda, Takeshi Onaka, Satoru Masuyama, Ryouhei Saga, Katsunori Hayashi
  • Publication number: 20030197494
    Abstract: A DC-DC converter of low ripple voltages which has a bi-directional power conversion means between an input power source and a smoothing capacitor and can quickly change the output voltage independently of the load. Said DC-DC converter comprises a main circuit of a non-insulated step-down DC-DC converter comprising at least two semiconductor elements, a DC reactor, and a smoothing capacitor, means for generating a variable reference voltage, means for comparing a reference voltage generated by said reference voltage generating means by the output voltage and outputting differential voltage information, means for generating a signal to be applied to the control terminals of said semiconductor element according to said differential voltage information, and means for discriminating the direction of a current flowing through said DC reactor.
    Type: Application
    Filed: May 2, 2003
    Publication date: October 23, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Ryouhei Saga, Kyoichi Hosokawa
  • Publication number: 20030184937
    Abstract: 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 converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3 and a current larger than a predetermined peak cut level is discharged from the secondary battery 4 at the time of peak load. Further, when the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC-DC converter 5. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.
    Type: Application
    Filed: April 28, 2003
    Publication date: October 2, 2003
    Applicants: Hitachi, Ltd., Hitachi Maxell, Ltd., Hitachi Computer Peripherals Co., Ltd.
    Inventors: Akihiko Kanouda, Satoru Masuyama, Masato Isogai, Ryouhei Saga, Kenichi Onda, Norikazu Tokunaga
  • Patent number: 6603671
    Abstract: 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.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: August 5, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Norikazu Tokunaga, Kenichi Onda, Takeshi Onaka, Ryouhei Saga, Akihiko Kanouda
  • Patent number: 6580597
    Abstract: 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.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: June 17, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Mikiya Nohara, Ryouhei Saga, Morinobu Endo
  • Publication number: 20030107906
    Abstract: A DC power supply device comprises an AC/DC converter 1, a DC/DC converter 2, and a DC converter 3 converting DC power from a battery 4 to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit 100 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.
    Type: Application
    Filed: November 13, 2002
    Publication date: June 12, 2003
    Applicants: Hitachi, Ltd., Hitachi Computer Peripherals Co., Ltd., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Norikazu Tokunaga, Kenichi Onda, Takeshi Onaka, Satoru Masuyama, Ryouhei Saga, Katsunori Hayashi
  • Patent number: 6567261
    Abstract: 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.
    Type: Grant
    Filed: August 7, 2002
    Date of Patent: May 20, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Mikiya Nohara, Ryouhei Saga, Morinobu Endo
  • Publication number: 20030042878
    Abstract: 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.
    Type: Application
    Filed: March 19, 2002
    Publication date: March 6, 2003
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Mikiya Nohara, Ryouhei Saga, Morinobu Endo
  • Publication number: 20030039092
    Abstract: 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.
    Type: Application
    Filed: August 7, 2002
    Publication date: February 27, 2003
    Applicant: HITACHI, LTD.
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Mikiya Nohara, Ryouhei Saga, Morinobu Endo
  • Patent number: 6507507
    Abstract: A DC power supply device comprises an AC/DC converter 1, a DC/DC converter 2, and a DC converter 3 converting DC power from a battery 4 to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit 100 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.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: January 14, 2003
    Assignees: Hitachi, Ltd., Hitachi Computer Peripherals Co., Ltd., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Norikazu Tokunaga, Kenichi Onda, Takeshi Onaka, Satoru Masuyama, Ryouhei Saga, Katsunori Hayashi
  • Publication number: 20020186576
    Abstract: 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 converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3 and a current larger than a predetermined peak cut level is discharged from the secondary battery 4 at the time of peak load. Further, when the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC-DC converter 5. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.
    Type: Application
    Filed: February 27, 2002
    Publication date: December 12, 2002
    Inventors: Akihiko Kanouda, Satoru Masuyama, Masato Isogai, Ryouhei Saga, Kenichi Onda, Norikazu Tokunaga
  • Publication number: 20020185994
    Abstract: A DC-DC converter of low ripple voltages which has a bi-directional power conversion means between an input power source and a smoothing capacitor and can quickly change the output voltage independently of the load. Said DC-DC converter comprises a main circuit of a non-insulated step-down DC-DC converter comprising at least two semiconductor elements, a DC reactor, and a smoothing capacitor, means for generating a variable reference voltage, means for comparing a reference voltage generated by said reference voltage generating means by the output voltage and outputting differential voltage information, means for generating a signal to be applied to the control terminals of said semiconductor element according to said differential voltage information, and means for discriminating the direction of a current flowing through said DC reactor.
    Type: Application
    Filed: January 31, 2002
    Publication date: December 12, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Ryouhei Saga, Kyoichi Hosokawa
  • Patent number: 6489756
    Abstract: 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.
    Type: Grant
    Filed: March 14, 2001
    Date of Patent: December 3, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Ryouhei Saga
  • Publication number: 20020136030
    Abstract: 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.
    Type: Application
    Filed: November 30, 2001
    Publication date: September 26, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Norikazu Tokunaga, Kenichi Onda, Takeshi Onaka, Ryouhei Saga, Akihiko Kanouda
  • Publication number: 20020080631
    Abstract: The efficiency of the DC-DC converter that the load factor varies greatly is improved.
    Type: Application
    Filed: March 14, 2001
    Publication date: June 27, 2002
    Inventors: Akihiko Kanouda, Kenichi Onda, Norikazu Tokunaga, Ryouhei Saga
  • Publication number: 20020067630
    Abstract: A DC power supply device comprises an AC/DC converter 1, a DC/DC converter 2, and a DC converter 3 converting DC power from a battery 4 to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit 100 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.
    Type: Application
    Filed: October 31, 2001
    Publication date: June 6, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Norikazu Tokunaga, Kenichi Onda, Takeshi Onaka, Satoru Masuyama, Ryouhei Saga, Katsunori Hayashi
  • Patent number: 6381152
    Abstract: 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.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: April 30, 2002
    Assignees: Hitachi, Ltd., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Tadashi Takahashi, Kenichi Onda, Norikazu Tokunaga, Takeshi Onaka, Ryouhei Saga, Katsunori Hayashi