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:
Dec. 31, 2002
Filed:
Aug. 06, 2001
Applicant:
Inventor:
John G. Konopka, Deer Park, IL (US);
Assignee:
Osram Sylvania Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 3/702 ;
U.S. Cl.
CPC ...
H05B 3/702 ;
Abstract
A ballast ( ) for powering a gas discharge lamp ( ) having heatable filaments ( ) includes a filament heating and protection circuit ( ) that provides preheating of the filaments, efficiently reduces the filament heating power after the lamp ignites, quickly responds to removal or failure of the lamp in order minimize power dissipation in the ballast, and operates a replaced lamp without requiring cycling of the power to the ballast. In a preferred embodiment, filament heating and protection circuit ( ) includes a transformer ( ), a switching circuit ( ), a turn-on circuit ( ), and a lamp-out detection circuit ( ).