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. 08, 2003
Filed:
Oct. 25, 2001
Applicant:
Inventors:
Marcel Beij, Eindhoven, NL;
Arnold Willem Buij, Eindhoven, NL;
Assignee:
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F 1/00 ;
U.S. Cl.
CPC ...
G05F 1/00 ;
Abstract
A ballast circuit for operating a discharge lamp is equipped with a timer for measuring the service life of the lamps, and with means for increasing the power supplied to the lamp as the number of burning hours increase. The decrease in efficiency associated with the increase in burning hours is compensated thereby.