Patents by Inventor Hiroyuki Aoyama

Hiroyuki Aoyama 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: 4858096
    Abstract: An impedance for short-circuit prevention is connected with a secondary winding side of a transformer of a resonant converter comprising a resonant circuit, a D.C. input source, and a switching devices. The short-circuit prevention impedance is driven by the driving current generated in a driving winding in accordance with a resonance current at the primary winding side of the transformer, thereby obviating the stop of an oscillation. The oscillation can be stopped at a timing of not generating a surge voltage in the switching devices by detecting a current returning to the D.C. input power source.
    Type: Grant
    Filed: April 6, 1988
    Date of Patent: August 15, 1989
    Assignees: Hitachi, Ltd., Hitachi Metals, Ltd.
    Inventors: Kenichi Onda, Yasuo Matsuda, Kojin Abe, Yasunori Iwafuji, Hiroyuki Aoyama, Hideo Yoshinaka