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:
Nov. 22, 2011
Filed:
Nov. 25, 2005
Georg Sauerlaender, Aachen, DE;
Reinhold Elferich, Aachen, DE;
Bernd Ackermann, Aachen, DE;
Dirk Hente, Wuerselen, DE;
Christoph Martiny, Aachen, DE;
Matthias Wendt, Wuerselen, DE;
Georg Sauerlaender, Aachen, DE;
Reinhold Elferich, Aachen, DE;
Bernd Ackermann, Aachen, DE;
Dirk Hente, Wuerselen, DE;
Christoph Martiny, Aachen, DE;
Matthias Wendt, Wuerselen, DE;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A driver circuit for operating one or more light emitting diodes(LEDs) is disclosed. An alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element. The buffer element comprises an output choke, such as an inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.