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. 04, 1997
Filed:
Oct. 12, 1995
Anton C Blom, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A circuit for operating a lamp includes supply input terminals for connection to a supply voltage source and a transformer provided with a primary winding L1 and a secondary winding L2. A first branch has terminals (N1,N2) for holding the lamp and connects a first end of the secondary winding L2 to a second end thereof. A second branch comprising a series circuit of a switching element (Q1) and the primary winding L1 interconnects the supply input terminals. A control circuit (SC1) is coupled to a control electrode of the switching element for generating a control signal for rendering the switching element conducting and non-conducting, and thus generating a first current in the primary winding L1 and a second current in the secondary winding L2. The second branch comprises a series arrangement of the primary winding, the switching element (Q1), and the terminals (N1,N2) for connection to the lamp. The total lamp current is controlled via the switching element which passes only a portion of the lamp current.