Patents by Inventor Ohjhong Yoon

Ohjhong Yoon 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).

  • Detection of ground faults in ungrounded DC power supply systems
    Patent number: 4638245
    Abstract: An apparatus for detecting a ground fault in an ungrounded DC power supply system having a DC power supply connected by positive and negative lines to a load, an AC voltage is selectively applied between a positive line and ground or between a negative line and ground. A current sensor including an electrical coil surrounding the positive and negative lines is responsive to significant alternating current in one of the lines, when the AC voltage is applied to the line and the line has a ground fault, to thereby indicate the fault.
    Type: Grant
    Filed: January 8, 1985
    Date of Patent: January 20, 1987
    Assignee: Federal Pioneer Limited
    Inventors: Colin A. A. MacPhee, Ohjhong Yoon