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:
May. 25, 2004
Filed:
Sep. 30, 2002
Applicant:
Inventor:
Himamshu V. Prasad, Rolling Meadows, IL (US);
Assignee:
Osram Sylvania, Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 3/700 ;
U.S. Cl.
CPC ...
H05B 3/700 ;
Abstract
A ballast ( ) having an inverter ( ) and a direct current blocking capacitor ( ) coupled in series with a ballast output ( ) includes a control circuit ( ) for providing adaptive end-of-lamp-life protection. During operation, control circuit executes the steps of measuring ( ) and storing ( ) a reference value for the voltage across the DC blocking capacitor ( ), monitoring ( ) the voltage across the DC blocking capacitor ( ), and protecting ( ) the inverter and lamp sockets in response to the voltage across the DC blocking capacitor departing from the reference value by more than a predetermined threshold amount.