Patents by Inventor Isao Fujihata
Isao Fujihata 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).
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Patent number: 10263429Abstract: A low-voltage circuit in a bidirectional DC-DC converter converts output AC power from a high-voltage circuit to DC power to charge a smoothing reactor and discharge the smoothing reactor, and includes an active snubber circuit including switching elements and each having a backward diode and a snubber capacitor. The snubber capacitor of the active snubber circuit has its one end connected to a drain end of the switching elements, and has its other end connected to a node between a center tap of a high-frequency transformer and a smoothing reactor.Type: GrantFiled: January 25, 2016Date of Patent: April 16, 2019Assignee: OMRON CorporationInventors: Makoto Ohashi, Takeo Nishikawa, Takashi Hyodo, Isao Fujihata, Masayuki Suetomi, Masaaki Shimizu
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Patent number: 10230306Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device that performs a specific state transition of the DC/DC converter (10) after a change rate of a magnitude of a current flowing through a winding of a primary or secondary side of a transformer (TR) with respect to time reaches a value within a predetermined change rate range.Type: GrantFiled: May 2, 2017Date of Patent: March 12, 2019Assignee: OMRON CorporationInventors: Masayuki Suetomi, Katsuji Mitsui, Isao Fujihata, Kesanobu Kuwabara, Yoshihiko Yamaguchi, Makoto Ohashi
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Patent number: 10008938Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device in which a direction of a current flowing through a winding of a transformer (TR) is switched after a magnitude of the current flowing through the winding of the transformer (TR) reaches “0.Type: GrantFiled: May 2, 2017Date of Patent: June 26, 2018Assignee: OMRON CorporationInventors: Isao Fujihata, Masayuki Suetomi, Kesanobu Kuwabara, Makoto Ohashi, Yoshihiko Yamaguchi
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Publication number: 20180013291Abstract: A low-voltage circuit in a bidirectional DC-DC converter converts output AC power from a high-voltage circuit to DC power to charge a smoothing reactor and discharge the smoothing reactor, and includes an active snubber circuit including switching elements and each having a backward diode and a snubber capacitor. The snubber capacitor of the active snubber circuit has its one end connected to a drain end of the switching elements and has its other end connected to a node between a center tap of a high-frequency transformer and a smoothing reactor.Type: ApplicationFiled: January 25, 2016Publication date: January 11, 2018Applicant: OMRON CorporationInventors: Makoto OHASHI, Takeo NISHIKAWA, Takashi HYODO, Isao FUJIHATA, Masayuki SUETOMI, Masaaki SHIMIZU
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Patent number: 9847723Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device that performs a predetermined state transition of the DC/DC converter (10) after waiting for a load current value of a primary or secondary side of a transformer (TR) becomes a value within a predetermined current value range.Type: GrantFiled: May 2, 2017Date of Patent: December 19, 2017Assignee: OMRON CorporationInventors: Masayuki Suetomi, Katsuji Mitsui, Isao Fujihata, Kesanobu Kuwabara, Yoshihiko Yamaguchi, Makoto Ohashi
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Patent number: 9837908Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device that performs predetermined state transition of the DC/DC converter (10) after waiting for a load current value of a secondary side of a transformer (TR) to be a value within a predetermined current value range.Type: GrantFiled: May 2, 2017Date of Patent: December 5, 2017Assignee: OMRON CorporationInventors: Masayuki Suetomi, Katsuji Mitsui, Isao Fujihata, Kesanobu Kuwabara, Yoshihiko Yamaguchi, Makoto Ohashi
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Publication number: 20170324337Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device that performs predetermined state transition of the DC/DC converter (10) after waiting for a load current value of a secondary side of a transformer (TR) to be a value within a predetermined current value range.Type: ApplicationFiled: May 2, 2017Publication date: November 9, 2017Applicant: OMRON CorporationInventors: Masayuki SUETOMI, Katsuji MITSUI, Isao FUJIHATA, Kesanobu KUWABARA, Yoshihiko YAMAGUCHI, Makoto OHASHI
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Publication number: 20170324334Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device in which a direction of a current flowing through a winding of a transformer (TR) is switched after a magnitude of the current flowing through the winding of the transformer (TR) reaches “0.Type: ApplicationFiled: May 2, 2017Publication date: November 9, 2017Applicant: OMRON CorporationInventors: Isao FUJIHATA, Masayuki SUETOMI, Kesanobu KUWABARA, Makoto OHASHI, Yoshihiko YAMAGUCHI
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Publication number: 20170324336Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device that performs a specific state transition of the DC/DC converter (10) after a change rate of a magnitude of a current flowing through a winding of a primary or secondary side of a transformer (TR) with respect to time reaches a value within a predetermined change rate range.Type: ApplicationFiled: May 2, 2017Publication date: November 9, 2017Applicant: OMRON CorporationInventors: Masayuki SUETOMI, Katsuji MITSUI, Isao FUJIHATA, Kesanobu KUWABARA, Yoshihiko YAMAGUCHI, Makoto OHASHI
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Publication number: 20170324335Abstract: A power conversion device, which includes an insulation type full bridge converter and can switch a power transmission direction at a high speed, is provided. A DC/DC converter (10) constitutes a power conversion device, which operates as a first type converter that converts a voltage within a first range applied to a first input/output terminal pair into a voltage within a second range and outputs the voltage from a second input/output terminal pair or a second type converter that converts a voltage within the second range applied to the second input/output terminal pair into a voltage within the first range and outputs the voltage from the first input/output terminal pair, as a device that performs a predetermined state transition of the DC/DC converter (10) after waiting for a load current value of a primary or secondary side of a transformer (TR) becomes a value within a predetermined current value range.Type: ApplicationFiled: May 2, 2017Publication date: November 9, 2017Applicant: OMRON CorporationInventors: Masayuki SUETOMI, Katsuji MITSUI, Isao FUJIHATA, Kesanobu KUWABARA, Yoshihiko YAMAGUCHI, Makoto OHASHI
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Patent number: 4823023Abstract: A switching circuit is improved in efficiency by including a switching corrector circuit for feeding back reversed polarity, differentiated switching pulses to the base of the switching transistor. In addition, temperature stability is achieved by providing a constant current source for a drive transistor which drives the switching transistor and for a control transistor which controls the drive transistor on the basis of the detected output of the circuit.Type: GrantFiled: July 15, 1986Date of Patent: April 18, 1989Assignee: Nippon Chemi-Con CorporationInventors: Tetsuhiko Shimpo, Isao Fujihata, Atsushi Yanase
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Patent number: 4538101Abstract: A power supply device includes a plurality of switching regulators and a waveshaping circuit, or, a switching circuit for converting an input voltage to switching pulses, a transformer for transforming the voltage of the pulses generated in the switching circuit, a rectifier circuit for rectifying the switching pulses provided through the transformer, a switching regulator into which the resulting d.c. input is supplied from the rectifier circuit and a waveshaping circuit. The former waveshaping circuit shapes the waveform of switching pulses generated within one switching regulator of the plurality of switching regulators and supplies the shaped output to the other switching regulators as an input reference waveform. The latter waveshaping circuit shapes the waveform of the switching pulses provided from the transformer and supplies the resulting function waveform to a pulse control unit in the switching regulator as an input reference waveform.Type: GrantFiled: June 3, 1983Date of Patent: August 27, 1985Assignee: Nippon Chemi-Con CorporationInventors: Tetsuhiko Shimpo, Isao Fujihata