Patents by Inventor Yukinori Maekawa

Yukinori Maekawa 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: 9257915
    Abstract: A bridge rectifier circuit has first to fourth diode groups which are bridge-connected and each include a main diode and sub-diodes being enabled to be respectively connected in parallel to the main diode, first and second input terminals to which AC power is supplied, a first output terminal connected to the first input terminal via the first diode group and connected to the second input terminal via the second diode group, a second output terminal connected to the first input terminal via the third diode group and connected to the second input terminal via the fourth diode group, and a control circuit configured to detect a current flowing through at least one diode group and increases the number of sub-diodes connected in parallel to the main diode of the diode group through which the detected current flows in accordance with an increase in the detected current.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: February 9, 2016
    Assignee: SOCIONEXT INC.
    Inventors: Hideta Oki, Yukinori Maekawa
  • Publication number: 20140098582
    Abstract: A bridge rectifier circuit has first to fourth diode groups which are bridge-connected and each include a main diode and sub-diodes being enabled to be respectively connected in parallel to the main diode, first and second input terminals to which AC power is supplied, a first output terminal connected to the first input terminal via the first diode group and connected to the second input terminal via the second diode group, a second output terminal connected to the first input terminal via the third diode group and connected to the second input terminal via the fourth diode group, and a control circuit configured to detect a current flowing through at least one diode group and increases the number of sub-diodes connected in parallel to the main diode of the diode group through which the detected current flows in accordance with an increase in the detected current.
    Type: Application
    Filed: August 22, 2013
    Publication date: April 10, 2014
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventors: Hideta Oki, Yukinori Maekawa
  • Patent number: 7777474
    Abstract: A DC-DC converter for converting an input voltage and generating an output voltage. The DC-DC converter includes an adjustment resistor. A control circuit generates a control signal and includes an external terminal to which the adjustment resistor is externally connected. A switching transistor is connected to the control circuit and turned on or off in accordance with the control signal. The control circuit includes an oscillator that generates an oscillation signal. The control circuit generates the control signal based on the oscillation signal and a signal that is in accordance with an output voltage or output current of the DC-DC converter. The oscillator monitors a first amount of current flowing through the external terminal of the control circuit and generates the oscillation signal in a cycle that is accordance with the monitoring result.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: August 17, 2010
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Yukinori Maekawa, Yoshihiro Nagaya, Keita Sekine, Takashi Matsumoto, Takehito Doi
  • Publication number: 20070285074
    Abstract: A DC-DC converter for converting an input voltage and generating an output voltage. The DC-DC converter includes an adjustment resistor. A control circuit generates a control signal and includes an external terminal to which the adjustment resistor is externally connected. A switching transistor is connected to the control circuit and turned on or off in accordance with the control signal. The control circuit includes an oscillator that generates an oscillation signal. The control circuit generates the control signal based on the oscillation signal and a signal that is in accordance with an output voltage or output current of the DC-DC converter. The oscillator monitors a first amount of current flowing through the external terminal of the control circuit and generates the oscillation signal in a cycle that is accordance with the monitoring result.
    Type: Application
    Filed: April 26, 2007
    Publication date: December 13, 2007
    Inventors: Yukinori Maekawa, Yoshihiro Nagaya, Keita Sekine, Takashi Matsumoto, Takehito Doi