Patents by Inventor Frederik H. Gerritsen

Frederik H. Gerritsen 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).

  • Telephone subscriber line looping circuit
    Patent number: 4476352
    Abstract: A line looping circuit for connection between the wires of a subscriber's line via the hook contact and in parallel with further equipment of the subscriber's set. The circuit comprises the series arrangement of the main current path of one or two field effect transistors and a resistor, the gate of each field effect transistor being connected to the end of the resistor remote from that field effect transistor. The circuit has a low resistance to small currents and a high resistance to high currents.
    Type: Grant
    Filed: March 30, 1982
    Date of Patent: October 9, 1984
    Assignee: U.S. Philips Corporation
    Inventors: Frederik H. Gerritsen, Daniel J. G. Janssen