Patents by Inventor Yosuko Tsujikura

Yosuko Tsujikura 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).

  • Differential protective relay apparatus
    Patent number: 5095399
    Abstract: A differential protective relay apparatus is switched over between a current differential mode and a voltage differential mode automatically by both even-order harmonic components of an imput applied to a differential circuit and a voltage across an impedance of the differential circuit, thereby to cover extensive fault modes while retaining high minimum pickup sensitivity, furthermore, devised against excessive fault voltages in the voltage differential mode, and, consequently, advantageous in insulation withstand capability.
    Type: Grant
    Filed: August 9, 1990
    Date of Patent: March 10, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Makoto Terada, Yosuko Tsujikura