Patents by Inventor Hajime Katsushima

Hajime Katsushima 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: 8873259
    Abstract: A DC-DC converter includes a regeneration snubber circuit. The snubber circuit is connected in parallel with the secondary diode circuit and includes a series circuit of a discharge blocking diode, a snubber capacitor, and a switching element for regeneration connected in parallel with the discharge blocking diode. The DC-DC converter further includes a control unit which turns the switching element for regeneration on a predetermined time period after the timing of turning the primary side switching element off. The predetermined time period is set to approximately the time period during which the charge, accumulated in the snubber capacitor due to reverse recovery time when one of the secondary diodes has been turned off, discharges.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: October 28, 2014
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Patent number: 8400799
    Abstract: This inverter circuit includes first and second switching elements and an output transformer which is provided with a first primary winding connected in series between said first and second switching elements, and also with a secondary winding for obtaining an output voltage. The inverter circuit is further provided with a first voltage supply, a second voltage supply, and a control unit. The first voltage supply applies voltage to said first switching element via said first primary winding. And the second voltage supply applies voltage to said second switching element via said second primary winding. The control unit turns said first switching element and said second switching element alternatingly ON and OFF. This inverter circuit also includes first and second regeneration snubber circuits for regenerating the charge charged into snubber capacitors.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: March 19, 2013
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Patent number: 8363432
    Abstract: This DC-DC converter circuit includes: first and second switching elements (S1, S2); an output transformer (T) that includes a first primary winding (P1) connected in series between the positive electrode sides of the first and second switching elements (S1, S2), a second primary winding (P2) connected in series between their negative electrode sides, a secondary winding (S) for obtaining an output voltage, and tertiary windings (n3, n4); a first voltage source (C1), connected between a first connection point at which the first primary winding (P1) is connected to the second switching element (S2) and the first switching element (S1), that applies a voltage to the first switching element via the first primary winding; a second voltage source (C2) connected to locations symmetric with those of the first voltage source (C1); and a control unit (CT) that turns the first and second switching elements (S1, S2) alternatingly ON and OFF, and first and second regeneration snubber circuits (SN1, SN2) for regenerating
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: January 29, 2013
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Hajime Katsushima, Toshikazu Fujiyoshi, Kenji Morimoto, Hajime Yamamoto, Satoshi Yamamura
  • Publication number: 20120243263
    Abstract: This DC-DC converter circuit includes: first and second switching elements (S1, S2); an output transformer (T) that includes a first primary winding (P1) connected in series between the positive electrode sides of the first and second switching elements (S1, S2), a second primary winding (P2) connected in series between their negative electrode sides, a secondary winding (S) for obtaining an output voltage, and tertiary windings (n3, n4); a first voltage source (C1), connected between a first connection point at which the first primary winding (P1) is connected to the second switching element (S2) and the first switching element (S1), that applies a voltage to the first switching element via the first primary winding; a second voltage source (C2) connected to locations symmetric with those of the first voltage source (C1); and a control unit (CT) that turns the first and second switching elements (S1, S2) alternatingly ON and OFF, and first and second regeneration snubber circuits (SN1, SN2) for regenerating
    Type: Application
    Filed: December 16, 2009
    Publication date: September 27, 2012
    Inventors: Hajime Katsushima, Toshikazu Fujiyoshi, Kenji Morimoto, Hajime Yamamoto, Satoshi Yamamura
  • Patent number: 8107265
    Abstract: This inverter circuit includes two switching elements which are turned alternately ON and OFF, and a first primary winding connected in series between these switching elements, and also includes an output transformer having a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage source and a second voltage source. The first voltage source applies a voltage to the first switching element via the first primary winding. And the second voltage source applies a voltage to the second switching element via the second primary winding. This inverter circuit also includes a regeneration snubber circuit for regenerating charge accumulated in a snubber capacitor. The regeneration snubber circuit includes a regeneration circuit including a voltage boost section which converts the primary side voltage of the output transformer to a predetermined voltage, which it outputs.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: January 31, 2012
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Patent number: 8094470
    Abstract: This current balanced push-pull type inverter circuit includes first and second switching elements, and an output transformer which includes a first primary winding and a second primary winding connected in series between said first and second switching elements, and also includes a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage supply capacitor, a second voltage supply capacitor, and a control unit. A first snubber circuit, in which a first free wheel diode and first and second snubber capacitors are connected in series, is connected in inverse parallel to the first switching element. A first discharge resistor is connected between the first snubber capacitor and a first power supply capacitor, and a second discharge resistor is connected between the second snubber capacitor and a third power supply capacitor. And a second snubber circuit and discharge resistors are connected to the second switching element as well, in a similar manner.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: January 10, 2012
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Patent number: 8094469
    Abstract: This inverter circuit includes first and second switching elements and an output transformer which has a first primary winding connected in series between the first switching element and the second switching element and a second primary winding for obtaining an output voltage. The inverter circuit also includes a first voltage source, a second voltage source, and a control unit. The first voltage source is connected between a first connection point at which the first primary winding is connected to the second switching element, and the first switching element, and applies a voltage to the first switching element via the first primary winding. And the second voltage source is connected between a second connection point at which the first primary winding is connected to the first switching element, and the second switching element, and applies a voltage to the second switching element via the first primary winding.
    Type: Grant
    Filed: November 27, 2008
    Date of Patent: January 10, 2012
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Patent number: 8072188
    Abstract: This power supply device includes a series circuit of a first switching element and a second switching element connected in parallel with a DC power supply unit, and a smoothing filter circuit which includes a series circuit of an inductor and a smoothing capacitor connected in parallel with the second switching element. The power supply device also includes a control unit and a drive circuit for generating first and second PWM pulses by respectively driving the first and second switching elements ON and OFF, and for creating a dead time between those switching pulse signals. And this control unit changes the frequency of the switching pulse signal according to the pulse width of either the first PWM pulses or the second PWM pulses.
    Type: Grant
    Filed: September 22, 2008
    Date of Patent: December 6, 2011
    Assignee: Sansha Electric Manufacturing Co., Ltd.
    Inventors: Masanori Yorinobu, Shigeru Okamoto, Hajime Katsushima
  • Publication number: 20110280048
    Abstract: This DC-DC converter circuit includes a switching circuit which switches a DC power supply with a primary side switching element, a transformer to a primary side winding whereof the output of the switching circuit is applied and which outputs a voltage which has been changed by a predetermined voltage change ratio to a secondary side winding, and secondary diodes for current adjustment connected to the secondary side winding of the transformer. Moreover, it includes a regeneration snubber circuit connected in parallel with the secondary diode circuit and including a series circuit of a discharge blocking diode and a snubber capacitor and a switching element for regeneration connected in parallel with the discharge blocking diode, a filter circuit connected between rectification outputs of the secondary diode circuit, and a control unit which turns the switching element for regeneration ON a predetermined time period after the timing of turning the primary side switching element OFF.
    Type: Application
    Filed: February 25, 2009
    Publication date: November 17, 2011
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Publication number: 20110280054
    Abstract: This inverter circuit includes first and second switching elements and an output transformer which has a first primary winding connected in series between the first switching element and the second switching element and a second primary winding for obtaining an output voltage. The inverter circuit also includes a first voltage source, a second voltage source, and a control unit. The first voltage source is connected between a first connection point at which the first primary winding is connected to the second switching element, and the first switching element, and applies a voltage to the first switching element via the first primary winding. And the second voltage source is connected between a second connection point at which the first primary winding is connected to the first switching element, and the second switching element, and applies a voltage to the second switching element via the first primary winding.
    Type: Application
    Filed: November 27, 2008
    Publication date: November 17, 2011
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Publication number: 20110216557
    Abstract: This inverter circuit includes first and second switching elements and an output transformer which is provided with a first primary winding connected in series between said first and second switching elements, and also with a secondary winding for obtaining an output voltage. The inverter circuit is further provided with a first voltage supply, a second voltage supply, and a control unit. The first voltage supply applies voltage to said first switching element via said first primary winding. And the second voltage supply applies voltage to said second switching element via said second primary winding. The control unit turns said first switching element and said second switching element alternatingly ON and OFF. This inverter circuit also includes first and second regeneration snubber circuits for regenerating the charge charged into snubber capacitors.
    Type: Application
    Filed: February 6, 2009
    Publication date: September 8, 2011
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Publication number: 20110058395
    Abstract: This current balanced push-pull type inverter circuit includes first and second switching elements, and an output transformer which includes a first primary winding and a second primary winding connected in series between said first and second switching elements, and also includes a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage supply capacitor, a second voltage supply capacitor, and a control unit. A first snubber circuit, in which a first free wheel diode and first and second snubber capacitors are connected in series, is connected in inverse parallel to the first switching element. A first discharge resistor is connected between the first snubber capacitor and a first power supply capacitor, and a second discharge resistor is connected between the second snubber capacitor and a third power supply capacitor. And a second snubber circuit and discharge resistors are connected to the second switching element as well, in a similar manner.
    Type: Application
    Filed: March 10, 2009
    Publication date: March 10, 2011
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Publication number: 20110049989
    Abstract: This inverter circuit includes two switching elements which are turned alternately ON and OFF, and a first primary winding connected in series between these switching elements, and also includes an output transformer having a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage source and a second voltage source. The first voltage source applies a voltage to the first switching element via the first primary winding. And the second voltage source applies a voltage to the second switching element via the second primary winding. This inverter circuit also includes a regeneration snubber circuit for regenerating charge accumulated in a snubber capacitor. The regeneration snubber circuit includes a regeneration circuit including a voltage boost section which converts the primary side voltage of the output transformer to a predetermined voltage, which it outputs.
    Type: Application
    Filed: January 30, 2009
    Publication date: March 3, 2011
    Inventors: Toshikazu Fujiyoshi, Hajime Katsushima, Kenji Morimoto, Satoshi Yamamura
  • Publication number: 20090237028
    Abstract: This power supply device includes a series circuit of a first switching element and a second switching element connected in parallel with a DC power supply unit, and a smoothing filter circuit which includes a series circuit of an inductor and a smoothing capacitor connected in parallel with the second switching element. The power supply device also includes a control unit and a drive circuit for generating first and second PWM pulses by respectively driving the first and second switching elements ON and OFF, and for creating a dead time between those switching pulse signals. And this control unit changes the frequency of the switching pulse signal according to the pulse width of either the first PWM pulses or the second PWM pulses.
    Type: Application
    Filed: September 22, 2008
    Publication date: September 24, 2009
    Inventors: Masanori YORINOBU, Shigeru Okamoto, Hajime Katsushima