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:
Sep. 08, 2009
Filed:
Jul. 21, 2006
Brent Gawrys, Whitehall, PA (US);
Jecko J. Arakkal, Emmaus, PA (US);
Mark S. Taipale, Harleysville, PA (US);
Dragan Veskovic, Allentown, PA (US);
Mark Charles Fischer, Siler City, NC (US);
Brent Gawrys, Whitehall, PA (US);
Jecko J. Arakkal, Emmaus, PA (US);
Mark S. Taipale, Harleysville, PA (US);
Dragan Veskovic, Allentown, PA (US);
Mark Charles Fischer, Siler City, NC (US);
Lutron Electronics Co., Inc., Coopersburg, PA (US);
Abstract
An electronic dimming ballast comprises a filament turn-off circuit for controlling the magnitudes of filament voltages supplied to the filaments of a gas discharge lamp. Each of a plurality of filament windings is directly coupled to one of the filaments and is operable to supply a small AC filament voltage to the filaments. The plurality of filament windings and a control winding are loosely magnetically coupled to a resonant inductor of an output circuit of the ballast. A controllably conductive device is coupled across the control winding. When the controllably conductive device is conductive, the voltage across the control winding and the filament windings falls to zero volts. The controllably conductive device is driven with a pulse-width modulated (PWM) signal so as to control the magnitudes of the filament voltages. The filament voltages are provided to the filaments before striking the lamp, and when dimming the lamp near low end.