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. 02, 1999
Filed:
Jul. 02, 1996
Joseph M Allison, Euclid, OH (US);
General Electric Company, Schenectady, NY (US);
Abstract
A universal electronic ballast self-accommodates to appropriately supply power to each one of a family of different fluorescent lamps, one at a time. The ballast comprises a circuit for supplying a.c. current to a lamp in such manner that current in the lamp varies as a function of an error voltage. A summing circuit is provided together with an error amplifier for amplifying the output of the summing circuit to produce the error voltage. A circuit produces a reference voltage that is supplied to the summing circuit. A current feedback circuit feeds back to the summing circuit a first signal that varies as a function of lamp current. A voltage feedback circuit feeds back to the summing circuit at least a second signal that varies as a function of lamp voltage in such manner as to realize a ballast current-voltage characteristic that intersects respective lamp current-voltage characteristics at desired operating power for each of the family of lamps.