Patents by Inventor Ryohji MATSUI

Ryohji MATSUI 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: 9519016
    Abstract: A ground fault detection apparatus is an apparatus detecting a ground fault in an ungrounded AC circuit in which a single-phase three-wire AC power source is connected to a load via a U phase wire, a neutral wire, and a V phase wire, including two resistive elements having an identical resistance value, one terminals of the two resistive elements being connected to the U phase wire and the neutral wire, respectively, the other terminals thereof being connected to each other. The ground fault detection apparatus further includes a current detector detecting a value of a current flowing between the other terminals of the two resistive elements (i.e., a node N1) and a ground point. In a case where the absolute value of the current exceeds a threshold value, the ground fault detection apparatus determines that a ground fault occurs.
    Type: Grant
    Filed: June 9, 2014
    Date of Patent: December 13, 2016
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Katsuhiko Satoh, Ryohji Matsui, Hiroshi Kawamura
  • Publication number: 20140361784
    Abstract: A ground fault detection apparatus is an apparatus detecting a ground fault in an ungrounded AC circuit in which a single-phase three-wire AC power source is connected to a load via a U phase wire, a neutral wire, and a V phase wire, including two resistive elements having an identical resistance value, one terminals of the two resistive elements being connected to the U phase wire and the neutral wire, respectively, the other terminals thereof being connected to each other. The ground fault detection apparatus further includes a current detector detecting a value of a current flowing between the other terminals of the two resistive elements (i.e., a node N1) and a ground point. In a case where the absolute value of the current exceeds a threshold value, the ground fault detection apparatus determines that a ground fault occurs.
    Type: Application
    Filed: June 9, 2014
    Publication date: December 11, 2014
    Inventors: Katsuhiko SATOH, Ryohji MATSUI, Hiroshi KAWAMURA