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:
Apr. 21, 2009
Filed:
Dec. 09, 2004
William L. Keith, Lake in the Hills, IL (US);
George L. Grouev, Arlington Heights, IL (US);
Kent E. Crouse, Carpentersville, IL (US);
William L. Keith, Lake in the Hills, IL (US);
George L. Grouev, Arlington Heights, IL (US);
Kent E. Crouse, Carpentersville, IL (US);
Koninlijke Philips Electronics, N.V., Eindhoven, NL;
Abstract
An electronic ballast includes open circuit voltage regulation comprises an filament current sensing circuitoperably connected to an output of the electronic ballast and generating a sensed output voltage signal, and a regulating pulse width modulator Ureceiving the sensed output voltage signal and operably connected to control voltage at the output of the electronic ballast, the regulating pulse width modulator Uhaving an output voltage threshold limit. The regulating pulse width modulator Ulimits the voltage at the output of the electronic ballast when the sensed output voltage signal exceeds the output voltage threshold limit. The regulating pulse width modulator Ucan limit the output voltage by limiting the pulse width to the high voltage driver and the resonant half bridge. The filament current sensing circuitcan sense the output voltage indirectly, such as by sensing tank current, or can sense the output voltage directly.