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:
Oct. 09, 2007
Filed:
Feb. 02, 2004
Michael Winkel, Lüdenscheid, DE;
Franz Tusch, Plettenberg, DE;
Michael Winkel, Lüdenscheid, DE;
Franz Tusch, Plettenberg, DE;
HEP Tech Co. Ltd., RC Taichung, TW;
Abstract
The invention relates to a ballast for low-pressure discharge lamps, comprising a controllable inverter circuit for the generation of a high-frequency supply voltage for a discharge lamp (), a lamp inductance (L) connected to the inverter circuit, a lamp parallel capacitor (C) which is serially connected to the lamp inductance (L) and connected in parallel to the discharge lamp (), and a preheating circuit supplying heating current to the electrodes () of the discharge lamp (). In order to minimize electrical losses and to enable universal use of said ballast for various types of discharge lamps the invention proposes that current is supplied to the preheating circuit via an auxiliary winding () arranged on the lamp inductance (L) with said auxiliary winding () being connected with the preheating circuit via a controllable switch or a parallel resonant circuit ().