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:
Mar. 06, 2007
Filed:
Jun. 30, 2005
Naveen Yadlapalli, Hoffman Estates, IL (US);
Naveen Yadlapalli, Hoffman Estates, IL (US);
Osram Sylvania, Inc., Danvers, MA (US);
Abstract
A ballast () for powering at least one gas discharge lamp () includes an EMI filter (), a full-wave rectifier (), a DC-to-DC converter (), an inverter (), an output circuit (), and a microcontroller (). In response to an output ground-fault condition wherein at least one output terminal () of the ballast () is shorted to earth ground, the microcontroller () directs the DC-to-DC converter () to remain in a non-operating mode wherein the output voltage of the DC-to-DC converter () is substantially zero, thereby protecting the inverter () from damage. Preferably, the microcontroller () monitors a voltage across a DC blocking capacitor () within the output circuit () prior to startup of the DC-to-DC converter () in order to determine if an output ground-fault condition is present.