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. 05, 2006
Filed:
Mar. 31, 2005
Grigoriy A. Trestman, Salem, MA (US);
Joseph L. Parisella, Beverly, MA (US);
Grigoriy A. Trestman, Salem, MA (US);
Joseph L. Parisella, Beverly, MA (US);
Osram Sylvania, Inc., Danvers, MA (US);
Abstract
An electronic ballast () for powering a lamp load comprising an even number of gas discharge lamps () includes an inverter (), an output circuit (), and a protection circuit (). During operation, protection circuit () disables the inverter () in response to an end-of-lamp-life condition that is characterized by a predetermined imbalance in the operating current provided to each of the even number of lamps. Preferably, the output circuit () includes a current-sensing transformer () for detecting the predetermined imbalance, and the protection circuit () includes a silicon-controlled rectifier () for disabling the inverter ().