Patents by Inventor Ryszard Kitajewski

Ryszard Kitajewski 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).

  • Ring trip detector
    Patent number: 4022980
    Abstract: A Hall effect device is employed in telephone exchange circuitry for detecting when a called subscriber goes off-hook. This is done by detecting when a DC current due to line looping is superimposed on the AC current due to ringing whereupon ring trip occurs. Also described are circuits in which after ring trip has taken place the Hall device continues to supervise the called line loop.
    Type: Grant
    Filed: March 3, 1976
    Date of Patent: May 10, 1977
    Assignee: International Standard Electric Corporation
    Inventors: Ryszard Kitajewski, Anthony William Sweet, Michael Philip Dyer
  • Presence and direction of line current flow detector
    Patent number: 4020294
    Abstract: A Hall effect device is employed to monitor the presence and direction of line current flow. The output of the Hall effect device is fed to an amplifier having a known output level for a zero input. The output of the amplifier will increase or decrease dependent on the direction of the current flow. The output of the amplifier is monitored for change and direction of change of current flow.
    Type: Grant
    Filed: March 25, 1976
    Date of Patent: April 26, 1977
    Assignee: International Standard Electric Corporation
    Inventors: Ryszard Kitajewski, Anthony William Sweet, Michael Philip Dyer