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:
Jul. 09, 2013
Filed:
Jun. 29, 2010
Wei Xiong, Madison, AL (US);
Thomas Lunn, Hazel Green, AL (US);
Christopher Radzinski, Huntsville, AL (US);
Wei Xiong, Madison, AL (US);
Thomas Lunn, Hazel Green, AL (US);
Christopher Radzinski, Huntsville, AL (US);
Panasonic Corporation, Osaka, JP;
Abstract
An electronic ballast for fluorescent lighting includes an inverter circuit having an output circuit coupled to a pair of lamp terminals. A protection circuit is coupled to one of the lamp terminals. The protection circuit includes a differential voltage sensing circuit that is functional to sense the lamp voltage pulses as sudden changes in voltage across a DC blocking capacitor and, in response, to provide a positive AC voltage pulse. A pulse accumulation circuit is coupled to the differential voltage sensing circuit. The pulse accumulation circuit is responsive to the positive AC voltage pulses from the differential voltage sensing circuit to accumulate the positive AC voltage pulses into the ballast shutdown signal.