Patents by Inventor Clive R. Harris

Clive R. Harris 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).

  • Circuit for supplying constant voltage to a lamp from an AC input
    Patent number: 5576614
    Abstract: A circuit is provided for obtaining precise lamp voltage control and for compensating for varying or fluctuating input from an AC voltage source. The lamp is switched on by a switching device such as a triac. When the triac is powered, a simultaneous powering occurs of a second switching device such as an SCR. The SCR produces a scaled down RMS voltage output which closely matches the actual RMS lamp voltage. This second simulated voltage is precisely controlled in a feedback circuit which includes an RMS to DC converter and a feedback controller. The controller compares a converted DC voltage with a reference voltage and generates a firing pulse to the triac which is advanced or delayed so as to compensate for variations in the AC source as manifested by variations in the converted DC signal relative to the reference signal.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: November 19, 1996
    Assignee: Xerox Corporation
    Inventors: David J. Meads, Keith L. Bedford, Robert Kennedy, Clive R. Harris