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:
Nov. 12, 2013
Filed:
Dec. 09, 2011
Wei Xiong, Madison, AL (US);
John J Dernovsek, Madison, AL (US);
Candice Ungacta, Huntsville, AL (US);
Danny Pugh, Harvest, AL (US);
Wei Xiong, Madison, AL (US);
John J Dernovsek, Madison, AL (US);
Candice Ungacta, Huntsville, AL (US);
Danny Pugh, Harvest, AL (US);
Universal Lighting Technologies, Inc., Madison, AL (US);
Abstract
An electronic ballast is provided with circuitry for detecting the removal of one or more lamp filaments across a range of dimming levels, and regulating an output stage including at least first and second pairs of lamp connection output terminals based on a filament connection status. A filament removal sensing circuit is coupled to the output terminal pairs and configured to generate an output voltage representative of a filament connection status with respect to the output terminal pairs. A microcontroller is coupled to receive the output voltage from the filament removal sensing circuit and programmed to determine a rate of change in the output voltage, compare the rate of change in the output voltage to a predetermined threshold value, and disable the output stage when the rate of change in the output voltage exceeds the predetermined threshold value.