Patents by Inventor David P. Sonner

David P. Sonner 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).

  • Apparatus for unit control and presence detection
    Patent number: 5581201
    Abstract: A digital control circuit is constructed to use a single signal line for the dual functions of control and sensing the presence of the controlled device. The control circuit includes a driver element having an output capable of being placed in a high impedance allowing the signal line to be pulled to a first predetermined voltage potential when the controlled device is connected thereto, and a second voltage potential when the controlled device is absent therefrom. A receiver circuit monitors the signal line to sense presence of the one or the other of the voltage potentials.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: December 3, 1996
    Assignee: Tandem Computers Incorporated
    Inventors: David P. Sonner, David A. Brown, Carl W. Kagy, William J. Watson