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. 01, 1997
Filed:
Aug. 23, 1995
Glenn D Garbowicz, Rosemont, IL (US);
Patrick E Troy, Chicago, IL (US);
Janis L Wetterich, Newark, IL (US);
Philips Electronics North America Corporation, New York, NY (US);
Abstract
A ballast for powering a fluorescent lamp with filaments requiring preheating. Control circuitry within the ballast delays an ignitor from being turned on until the filaments have been sufficiently preheated. The control circuitry is isolated and thereby protected from the high voltage pulses of the ignitor by an optocoupler. A SIDAC employed in the generation of the high voltage pulses is not relied upon for sensing full arc discharge of the lamp. The breakover voltage of the SIDAC can therefore be set at a much lower than conventional level resulting in the generation of more high voltage pulses over a prefixed period of time.