Patents by Inventor Koukichi Tobita

Koukichi Tobita 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).

  • Load control device for an AC circuit
    Patent number: 5959440
    Abstract: A motor controlling device for controlling the rotational speed of an AC motor (3) connected with an AC power supply (1) through a speed control thyrister (2) includes a negative charging circuit (5) for charging a negative half cycle voltage of the AC power supply (1) in a negative direction for each cycle to trigger the thyrister (2) in a positive half cycle period of the AC power supply (1), and a positive charging circuit (6) for charging a positive half cycle voltage of the AC power supply (1) in a positive direction from the end of the negative half cycle by the negative charging circuit (5) for each cycle to trigger the thyrister (2) when the charged voltage reaches a trigger voltage of the thyrister (2).
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: September 28, 1999
    Assignee: Omron Corporation
    Inventors: Koukichi Tobita, Hiroyuki Ohtsuka, Kazunori Kajitani