Patents by Inventor Katsumi Koyanagi

Katsumi Koyanagi 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).

  • Switching current and a relay device employed therein
    Patent number: 4855612
    Abstract: A switching circuit for supplying electric power to a load from a power source includes a first relay device having a first switch and a semiconductor switching element connected in series with the first switch, power source and load. A second relay device is provided which is defined by a second switch connected parallelly to the semiconductor switching element and an actuating switch for enabling and disabling the semiconductor switching element. The second relay device is so arranged as to effect the make of the actuating switch and second switch in said order and to effect the break of the same in the opposite order. A delay circuit is provided for controlling the first and second relay devices such that when supplying a current to the load, the first and second relay devices are turned on in said order so that the first switch, the actuating switch and the second switch are turned on in said order.
    Type: Grant
    Filed: March 10, 1988
    Date of Patent: August 8, 1989
    Assignee: Omron Tateisi Electronics Co.
    Inventors: Hirofumi Koga, Katsumi Koyanagi
  • Switching circuit and a relay device employed to prevent arcing
    Patent number: 4772809
    Abstract: A switching circuit for supplying electric power to a load from a power source includes a first relay device having a first switch and a semiconductor switching element connected in series with the first switch, power source and load. A second relay device is provided which is defined by a second switch connected parallelly to the semiconductor switching element and an actuating switch for enabling and disabling the semiconductor switching element. The second relay device is so arranged as to effect the make of the actuating switch and second switch in said order and to effect the break of the same in the opposite order. A delay circuit is provided for controlling the first and second relay devices such that when supplying a current to the load, the first and second relay devices are turned on in said order so that the first switch, the actuating switch and the second switch are turned on in said order.
    Type: Grant
    Filed: November 27, 1984
    Date of Patent: September 20, 1988
    Assignee: Omron Tateisi Electronics Co.
    Inventors: Hirofumi Koga, Katsumi Koyanagi