Patents by Inventor Bruce G. Pringle

Bruce G. Pringle 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).

  • Patent number: 4791668
    Abstract: An interface circuit a.c. couples a transmission line and a port of a telecommunications facility. The transmission line may be of any of n characteristic impedances. The interface circuit includes a resistor network having at least 2n+1 resistor elements. The resistor network is connected to ground by at least one of the resistor elements. A switching device includes at least n switching elements being connected between n of the resistor elements and an input of an amplifier. A transformer includes first, second and third windings, the first winding being for connection to the transmission line, the second winding being connected between an output of the amplifier and a junction between the one of the resistor elements and at least another of the resistor elements, and the third winding being connected between ground and a point in the resistance network other than the junction. A resistor connects at least one of the n switching elements and the port of the telecommunication facility.
    Type: Grant
    Filed: September 23, 1987
    Date of Patent: December 13, 1988
    Assignee: Northern Telecom Limited
    Inventor: Bruce G. Pringle