Patents by Inventor John S. Engelhardt

John S. Engelhardt 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).

  • Room temperature dielectric HTSC cable
    Patent number: 6262375
    Abstract: A high temperature superconducting cable comprises a cryogenic core, with a superconducting material either inside the cryogenic core or wrapped around the core. A space maintained at a vacuum and functioning as a cryostat surrounds the core; within this space are a separator and superinsulation. A conventional dielectric at room temperature surrounds the superinsulation, and a conventional ground shield surrounds the conventional dielectric. This cable does not require a cryogenic dielectric and is of suitable size and nature to be used in retrofitting conventional cable pipes.
    Type: Grant
    Filed: September 24, 1992
    Date of Patent: July 17, 2001
    Assignee: Electric Power Research Institute, Inc.
    Inventors: John S. Engelhardt, Steven A. Boggs
  • Apparatus including novel bridge circuit
    Patent number: 3964315
    Abstract: A bridge circuit for measuring the D.C. resistance of a resistive element having an induced A.C. current comprises impedance legs whereby the A.C. component can be balanced out. The invention has particular application to the measurement of high-voltage cable conductor temperatures.
    Type: Grant
    Filed: January 11, 1974
    Date of Patent: June 22, 1976
    Assignee: The Anaconda Company
    Inventor: John S. Engelhardt