Patents by Inventor Takeshi Matuzaki

Takeshi Matuzaki 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: 4118749
    Abstract: An apparatus for protecting a synchronous machine from a field overvoltage is disclosed. The apparatus comprises a field excitation control circuit which is impressed with the armature voltage of the synchronous machine so as to provide a DC power supply for producing a DC output to excite the field winding of the synchronous machine, a first discharge circuit which is adapted to discharge the stored energy of the field winding when the synchronous machine is to be tripped under predetermined conditions, and a second discharge circuit for reducing the field voltage by allowing a field current to flow therethrough in response to generation of an overvoltage whose absolute value is higher than a predetermined level, across the field winding.
    Type: Grant
    Filed: March 30, 1977
    Date of Patent: October 3, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Matuzaki, Masuo Goto, Yasushi Momochi