Patents by Inventor Takeo Nishikawa

Takeo Nishikawa 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: 11329546
    Abstract: A power converter apparatus is provided to include a switching circuit, and a filter circuit. The switching circuit generates an AC voltage by switching a DC voltage at a predetermining switching frequency, and the filter circuit converts the AC voltage from the switching circuit into the DC voltage by low-pass filtering the AC voltage. The filter circuit induces first and second bypass capacitors, and an inductor. The first bypass capacitor bypasses noise of a first frequency component of the AC voltage from the switching circuit, and the second bypass capacitor bypasses noise of a second frequency component of the AC voltage from the switching circuit, which is lower than the first frequency component. The inductor is inserted between the first and second bypass capacitors, and the inductance thereof is set so that a resonance frequency of the filter circuit is lower than the switching frequency by insertion of the inductor.
    Type: Grant
    Filed: March 11, 2019
    Date of Patent: May 10, 2022
    Assignee: OMRON CORPORATION
    Inventors: Noriyuki Nosaka, Takeo Nishikawa, Wataru Okada, Satoshi Iwai, Takanori Ishii, Gun Eto
  • Publication number: 20210273553
    Abstract: A power converter apparatus is provided to include a switching circuit, and a filter circuit. The switching circuit generates an AC voltage by switching a DC voltage at a predetermined switching frequency, and the filter circuit converts the AC voltage from the switching circuit into the DC voltage by low-pass filtering the AC voltage. The filter circuit includes first and second bypass capacitors, and an inductor. The first bypass capacitor bypasses noise of a first frequency component of the AC voltage from the switching circuit, and the second bypass capacitor bypasses noise of a second frequency component of the AC voltage from the switching circuit, which is lower than the first frequency component. The inductor is inserted between the first and second bypass capacitors, and the inductance thereof is set so that a resonance frequency of the filter circuit is lower than multiple times the switching frequency by insertion of the inductor.
    Type: Application
    Filed: March 11, 2019
    Publication date: September 2, 2021
    Inventors: Noriyuki NOSAKA, Takeo NISHIKAWA, Wataru OKADA, Satoshi IWAI, Takanori ISHII, Gun ETO
  • Publication number: 20210242864
    Abstract: A driver circuit controls a first switch element. A first resistor is connected between the driver circuit and the first switch element. A second switch element is connected to the first switch element. An overcurrent detector circuit controls the second switch element based on an overcurrent current flowing through the first switch element. A second resistor is connected between the overcurrent detector circuit and the second switch element. The first and second resistor is set such that a turn-off time of the first switch element when the second switch element is turned on by the overcurrent detector circuit is longer than a turn-off time of the first switch element when the first switch element is turned off by the driver circuit.
    Type: Application
    Filed: March 11, 2019
    Publication date: August 5, 2021
    Inventors: Wataru OKADA, Satoshi IWAI, Noriyuki NOSAKA, Takeo NISHIKAWA, Kenji KOBAYASHI, Keiji SHIRAISHI
  • Publication number: 20210167692
    Abstract: A power converter apparatus is provided to include a switching circuit, and a filter circuit. The switching circuit generates an AC voltage by switching a DC voltage at a predetermining switching frequency, and the filter circuit converts the AC voltage from the switching circuit into the DC voltage by low-pass filtering the AC voltage. The filter circuit induces first and second bypass capacitors, and an inductor. The first bypass capacitor bypasses noise of a first frequency component of the AC voltage from the switching circuit, and the second bypass capacitor bypasses noise of a second frequency component of the AC voltage from the switching circuit, which is lower than the first frequency component. The inductor is inserted between the first and second bypass capacitors, and the inductance thereof is set so that a resonance frequency of the filter circuit is lower than the switching frequency by insertion of the inductor.
    Type: Application
    Filed: March 11, 2019
    Publication date: June 3, 2021
    Inventors: Noriyuki NOSAKA, Takeo NISHIKAWA, Wataru OKADA, Satoshi IWAI, Takanori ISHII, Gun ETO
  • Publication number: 20210135583
    Abstract: An isolated bidirectional DC-DC converter device includes a first full-bridge inverter and a second full-bridge inverter circuit connected via a transformer; the second full-bridge inverter circuit including high-side switching elements and low-side switching elements; and a control unit configured to repeatedly execute an input-side control and an output-side control when boosting the input voltage to the first full-bridge inverter circuit; the control unit selectively executes any of a first control and a second control as the output-side control. The first control maintains the high-side switching elements in the OFF state while alternating each of the low-side switching elements between the ON and OFF states; and the second control maintains the low-side switching elements in the OFF state while alternating each of the high-side switching element between the ON and OFF states.
    Type: Application
    Filed: February 27, 2018
    Publication date: May 6, 2021
    Applicant: OMRON Corporation
    Inventors: Makoto OHASHI, Yoshihiko YAMAGUCHI, Takeo NISHIKAWA, Takanori ISHII
  • Patent number: 10516346
    Abstract: A power converter is provided with an inverter unit for converting DC power from a DC power supply into AC power, and a control unit that generates a control signal for controlling the inverter unit. The control unit includes an impedance estimation unit that injects a disturbance signal into a load and derives an estimated value of an impedance of the load based on a voltage signal from the load into which the disturbance signal is injected, the impedance compensator unit whose control parameters are set based on the estimated value of the impedance, and that corrects an output current signal in accordance with the control parameters, a command value unit that outputs a command value indicating a control target value, and a control compensator unit that generates a control signal, based on the command value from the command value unit and the current signal from the impedance compensator unit.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: December 24, 2019
    Assignee: OMRON Corporation
    Inventors: Yuhki Kamatani, Takeo Nishikawa, Hironori Nakada
  • Publication number: 20190287716
    Abstract: A transformer includes a core configured to form a magnetic circuit and including a gap in at least a part of the core; a bobbin mounted on the core; a first winding wire that is wound on the bobbin in two or more separate layers including a layer closest to the gap and a layer farther away from the gap than the layer; and a second winding wire insulated from the first winding wire, and including a layer of the second winding wire wound between the layer and the layer of the first winding wire. The layer and the layer of the first winding wire are connected in series.
    Type: Application
    Filed: September 20, 2017
    Publication date: September 19, 2019
    Applicant: OMRON Corporation
    Inventors: Takeo NISHIKAWA, Toshiyuki YOKOI, Takayoshi TAWARAGI
  • Patent number: 10361628
    Abstract: Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. A noise eliminator in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch) and the radiator (heatsink). A conductive member of the noise eliminator is connected to a stable potential.
    Type: Grant
    Filed: October 16, 2017
    Date of Patent: July 23, 2019
    Assignee: OMRON Corporation
    Inventors: Shingo Nagaoka, Hiroyuki Onishi, Takeo Nishikawa
  • Publication number: 20190190402
    Abstract: A power converter is provided with an inverter unit for converting DC power from a DC power supply into AC power, and a control unit that generates a control signal for controlling the inverter unit. The control unit includes an impedance estimation unit that injects a disturbance signal into a load and derives an estimated value of an impedance of the load based on a voltage signal from the load into which the disturbance signal is injected, the impedance compensator unit whose control parameters are set based on the estimated value of the impedance, and that corrects an output current signal in accordance with the control parameters, a command value unit that outputs a command value indicating a control target value, and a control compensator unit that generates a control signal, based on the command value from the command value unit and the current signal from the impedance compensator unit.
    Type: Application
    Filed: November 6, 2018
    Publication date: June 20, 2019
    Applicant: OMRON Corporation
    Inventors: Yuhki KAMATANI, Takeo NISHIKAWA, Hironori NAKADA
  • Patent number: 10312795
    Abstract: An inverter has a plurality of switching elements, the states of which are each switched by a pulse signal supplied in accordance with a power grid voltage. The inverter is provided with: a switching circuit that converts an input DC voltage to an AC voltage and outputs the AC voltage to a pair of output lines; a filter circuit having output coils inserted in the output lines; a current detection sensor that detects the current flowing through the output coils; and a high-speed pulse control circuit that, when an absolute value of the detected current is a threshold value or more, stops the supply of the pulse signal to the switching circuit.
    Type: Grant
    Filed: January 11, 2017
    Date of Patent: June 4, 2019
    Assignee: OMRON Corporation
    Inventors: Takeo Nishikawa, Hironori Nakada, Satoshi Iwai, Hiroki Kawano, Yuhki Kamatani, Kuniyuki Hirai
  • Patent number: 10304754
    Abstract: A heat dissipation structure of a semiconductor device is provided, the semiconductor device including: an electrical bonding surface electrically connected to a substrate; and a heat dissipation surface as an opposite side of the electrical bonding surface. The heat dissipation surface makes contact with a heat spreader via a conductive TIM while the heat spreader makes contact with a heat sink via an insulating TIM. A surface of the heat spreader facing the semiconductor device includes a recess part formed in at least one part in a vicinity of an outer periphery of the semiconductor device.
    Type: Grant
    Filed: January 25, 2017
    Date of Patent: May 28, 2019
    Assignee: OMRON Corporation
    Inventors: Takeo Nishikawa, Takayoshi Tawaragi, Eiichi Omura
  • Patent number: 10263429
    Abstract: 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: Grant
    Filed: January 25, 2016
    Date of Patent: April 16, 2019
    Assignee: OMRON Corporation
    Inventors: Makoto Ohashi, Takeo Nishikawa, Takashi Hyodo, Isao Fujihata, Masayuki Suetomi, Masaaki Shimizu
  • Patent number: 10244617
    Abstract: Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. A noise eliminator in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch) and the radiator (heatsink). A flexible connecting line connected to a conductive member of the noise eliminator is connected to an on-board line disposed on a circuit board.
    Type: Grant
    Filed: October 17, 2017
    Date of Patent: March 26, 2019
    Assignee: OMRON Corporation
    Inventors: Shingo Nagaoka, Hiroyuki Onishi, Takeo Nishikawa, Kentaro Hamana
  • Patent number: 10211756
    Abstract: An inverter circuit provided in a power conversion device includes a full-bridge inverter, and a short circuit part. The short circuit part includes switching elements and clamp elements connected to the switching elements. The clamp elements suppress application of an excessive voltage such as a surge voltage to the switching elements.
    Type: Grant
    Filed: October 18, 2017
    Date of Patent: February 19, 2019
    Assignee: OMRON Corporation
    Inventors: Takeo Nishikawa, Wataru Okada, Takayoshi Tawaragi, Satoshi Iwai
  • Publication number: 20190027421
    Abstract: A heat dissipation structure of a semiconductor device is provided, the semiconductor device including: an electrical bonding surface electrically connected to a substrate; and a heat dissipation surface as an opposite side of the electrical bonding surface. The heat dissipation surface makes contact with a heat spreader via a conductive TIM while the heat spreader makes contact with a heat sink via an insulating TIM. A surface of the heat spreader facing the semiconductor device includes a recess part formed in at least one part in a vicinity of an outer periphery of the semiconductor device.
    Type: Application
    Filed: January 25, 2017
    Publication date: January 24, 2019
    Applicant: OMRON Corporation
    Inventors: Takeo NISHIKAWA, Takayoshi TAWARAGI, Eiichi OMURA
  • Patent number: 10079545
    Abstract: A current resonant type DC voltage converter includes: a switching circuit configured to generate an AC voltage from a DC input voltage; a LC resonance circuit configured to resonate in response to application of the AC voltage to a resonant capacitor and a resonant coil; a transformer having a primary side connected in series to the LC resonance circuit; a parallel resonant inductance present in parallel to the transformer; a rectifier circuit configured to rectify a current appearing on a secondary side of the transformer to generate a DC output voltage; and a parallel resonant inductance adjustment circuit configured to change the parallel resonant inductance.
    Type: Grant
    Filed: February 19, 2015
    Date of Patent: September 18, 2018
    Assignee: OMRON Corporation
    Inventors: Takeo Nishikawa, Takashi Hyodo, Toshiyuki Yokoi
  • Publication number: 20180248474
    Abstract: An inverter has a plurality of switching elements, the states of which are each switched by a pulse signal supplied in accordance with a power grid voltage. The inverter is provided with: a switching circuit that converts an input DC voltage to an AC voltage and outputs the AC voltage to a pair of output lines; a filter circuit having output coils inserted in the output lines; a current detection sensor that detects the current flowing through the output coils; and a high-speed pulse control circuit that, when an absolute value of the detected current is a threshold value or more, stops the supply of the pulse signal to the switching circuit.
    Type: Application
    Filed: January 11, 2017
    Publication date: August 30, 2018
    Applicant: OMRON Corporation
    Inventors: Takeo NISHIKAWA, Hironori NAKADA, Satoshi IWAI, Hiroki KAWANO, Yuhki KAMATANI, Kuniyuki HIRAI
  • Publication number: 20180048229
    Abstract: Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. A noise eliminator in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch) and the radiator (heatsink). A conductive member of the noise eliminator is connected to a stable potential.
    Type: Application
    Filed: October 16, 2017
    Publication date: February 15, 2018
    Applicant: OMRON Corporation
    Inventors: Shingo NAGAOKA, Hiroyuki ONISHI, Takeo NISHIKAWA
  • Publication number: 20180042104
    Abstract: Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. A noise eliminator in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch) and the radiator (heatsink). A flexible connecting line connected to a conductive member of the noise eliminator is connected to an on-board line disposed on a circuit board.
    Type: Application
    Filed: October 17, 2017
    Publication date: February 8, 2018
    Applicant: OMRON Corporation
    Inventors: Shingo NAGAOKA, Hiroyuki ONISHI, Takeo NISHIKAWA, Kentaro HAMANA
  • Publication number: 20180041138
    Abstract: An inverter circuit provided in a power conversion device includes a full-bridge inverter, and a short circuit part. The short circuit part includes switching elements and clamp elements connected to the switching elements. The clamp elements suppress application of an excessive voltage such as a surge voltage to the switching elements.
    Type: Application
    Filed: October 18, 2017
    Publication date: February 8, 2018
    Applicant: OMRON Corporation
    Inventors: Takeo NISHIKAWA, Wataru OKADA, Takayoshi TAWARAGI, Satoshi IWAI