Patents by Inventor Paul F. Hung

Paul F. Hung 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).

  • Protection and recovery of telephone line interface circuits
    Patent number: 5390231
    Abstract: An automatic protection and recovery method for a telephone line interface circuit is described. The interface circuit monitors current on the line, and in the event of a fault producing an excessive current a protection relay interrupts a connection of the interface circuit to the line, and the interface circuit monitors common mode voltage on the line. The interface circuit is reconnected in response to the monitored voltage being below a relatively high threshold. If a second interruption results, the interface circuit is then reconnected in response to the monitored voltage being below a lower threshold. If a further interruption results, the interface circuit enters a ground fault recovery process. The method facilitates protection and rapid recovery from arbitrary fault conditions on the telephone line.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: February 14, 1995
    Assignee: Northern Telecom Limited
    Inventors: Paul F. Hung, Stanley D. Rosenbaum, Joseph F. M. Darveau, Reinhard W. Rosch, Brian A. F. S. Sutherland, Francois Y. Tremblay