Patents by Inventor Richard Crawbuck

Richard Crawbuck 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).

  • Ground fault protection of gas lamp power supplies
    Patent number: 5892646
    Abstract: A power supply for powering a neon sign assembly includes a ground fault detection circuit having a current sensing circuit that produces a voltage that is proportional to the current that flows from a center tap of an output transformer, a phase-sensitive rectifier that receives output from the current sensing circuit and a reference voltage from the transformer and produces an output voltage that depends on the magnitude of the output from the current sensing circuit and the phase angle between the output from the current sensing circuit and the reference voltage, and an amplitude comparator that produces an output to a latch circuit only when an output voltage from the phase-sensitive rectifier is equal to or greater than a pre-set ground fault current limit.
    Type: Grant
    Filed: May 5, 1997
    Date of Patent: April 6, 1999
    Assignee: Ventex Group, LLC
    Inventors: Francis J. Parker, Emilian Padurariu, Richard Crawbuck