The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 2006
Filed:
Dec. 03, 2004
Qinghong Yu, Salem, MA (US);
Christopher Radzinski, Huntsville, AL (US);
John Jay Dernovsek, Madison, AL (US);
Peter Shackle, Rolling Hills Estates, CA (US);
Qinghong Yu, Salem, MA (US);
Christopher Radzinski, Huntsville, AL (US);
John Jay Dernovsek, Madison, AL (US);
Peter Shackle, Rolling Hills Estates, CA (US);
Universal Lighting Technologies, Inc., Madison, AL (US);
Abstract
An improved high input voltage instant start electronic ballast uses a substantially lossless snubber circuit. The substantially lossless snubber circuit is incorporated into the ballast to reduce turn off losses and increase the efficiency of the ballast. The snubber circuit includes two capacitors connected in parallel with respect to the two switching transistors or FETS in the inverter of the ballast. A series-resonant lamp voltage sensing circuit is also provided that uses a voltage dividing capacitor to accomplish lossless monitoring of the open circuit voltage of the ballast. A cable compensation circuit minimizes variations in the open circuit voltage due to the connecting and disconnecting of a cable to the ballast by limiting the turn on times of the transistors during high voltage conditions.