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. 02, 1985
Filed:
Mar. 09, 1983
Dennis Capewell, Easton, PA (US);
David G Luchaco, Macungie, PA (US);
Joel S Spira, Coopersburg, PA (US);
Lutron Electronics Co., Inc., Coopersburg, PA (US);
Abstract
A gas discharge lamp control circuit for an inductive ballast includes anti-parallel connected controlled rectifiers connected in series with the a.c. source and the ballast and anti-parallel connected controlled rectifiers which are connected in series with a current limiting and energy diversion capacitor and in shunt with the ballast. The controlled rectifiers of the series and shunt switching assemblies are controlled so that, in any given half wave, the related controlled rectifier of the shunt switching means turns on to discharge a capacitor into the normally conducting controlled rectifier of the series switching means to produce a notch in the voltage wave form applied to the inductive ballast. The capacitor acts as a current limiting impedance and acts to permit reversal of the voltage during the notch interval in the input voltage to the ballast, thereby to increase the RMS content of the voltage wave form. An automatic low end dim setting circuit maintains the low end setting regardless of the type of lamp or ballast which is employed. A notch signal generating circuit is provided which employs two phase-shifted signals fed into a comparator and compared to a common reference level.