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:
Jun. 06, 2000
Filed:
Jul. 20, 1998
Lin Lin, Clifton, NJ (US);
Duro-Test Corporation, Bloomfield, NJ (US);
Abstract
A compact fluorescent lamp and an electronic ballast therefor are mounted on a three-terminal base which can be fitted into a three-way-switched standard AC lamp socket, so as to be responsive to the three powered switch positions of the socket for generating three light output levels. The ballast includes an AC-to-DC conversion circuit which supplies a lamp driver including a DC-to-AC conversion circuit, an oscillatory circuit and a resonant circuit. In one embodiment the AC-to-DC conversion circuit includes a full bridge rectifier and a voltage doubler producing two operating voltage levels for the lamp driver and two frequency control voltage levels for the oscillator, the ballast generating three light output levels by using two operating voltages and two operating frequencies. One of the lamp filaments is connected in series with the supply circuit for the oscillator so that the oscillator is inoperative when the lamp is disconnected or its filament burns out, and there is a feedback circuit from the resonant circuit to the oscillator supply for stabilizing its operating frequency. In another embodiment the AC-to-DC conversion circuit includes a half bridge rectifier and two voltage doublers for producing three operating voltages for the lamp driver to generate the three light output levels.