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. 13, 2004
Filed:
Sep. 17, 2001
John G. Konopka, Deer Park, IL (US);
Osram Sylvania, Inc., Danvers, MA (US);
Abstract
A ballast ( ) for powering a gas discharge lamp load ( ) comprises a protection circuit ( ) operable to monitor an electrical signal ( ) in the ballast and disable the ballast for at least a predetermined period of time in response to a disturbance wherein at least a portion ( ) of the electrical signal ( ) exhibits a time-rate-of-change that exceeds the time-rate-of-change of the signal during normal operation of the ballast and gas discharge lamp load. Protection circuit ( ) is capable of disabling the ballast within a response time that is less than twice the period of the electrical signal. In a preferred embodiment that is suitable for ballasts with driven-type inverters, protection circuit ( ) comprises a latching device ( ) and a triggering circuit ( ). In a preferred embodiment that is suitable for ballasts with self-oscillating type inverters, protection circuit ( ) comprises a pull-down circuit ( ) and a negative voltage source ( ).