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);
Peter Shackle, Rolling Hills Estates, CA (US);
John Jay Dernovsek, Madison, AL (US);
Qinghong Yu, Salem, MA (US);
Christopher Radzinski, Huntsville, AL (US);
Peter Shackle, Rolling Hills Estates, CA (US);
John Jay Dernovsek, Madison, AL (US);
Universal Lighting Technologies, Inc., Madison, AL (US);
Abstract
An electronic ballast uses a voltage sampling circuit and a voltage control circuit to limit the open circuit voltage of the ballast. A lamp voltage sensing circuit is provided that uses a voltage dividing capacitor to accomplish lossless monitoring of the open circuit voltage of the ballast. A resistor placed in series with the sampling capacitor is used to create a voltage that turns a control transistor off and on. The control transistor produces a gating signal trimming signal that a half bridge driver uses to alter the gating signals provided to the inverter transistors of the ballast. A cable compensation circuit is included that minimizes variations in the open circuit voltage due to the connecting and disconnecting of a cable to the ballast by turning the control transistor off and on.