Patents by Inventor Shoji Katsuyama

Shoji Katsuyama 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).

  • AC/DC current detecting method
    Patent number: 5223789
    Abstract: An AC/DC current detection method that can detect small and large changes in current, by employing a high-frequency excitation current applied to a coil wrapped around an annular iron core. The change in this value is determined for operation in the region of the coercive force of the iron core or as the change in an extreme value thereof.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: June 29, 1993
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shoji Katsuyama, Yasutoshi Ide, Hideki Koyama