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. 08, 2005
Filed:
Feb. 12, 2002
Alois Biebl, Sankt Johann, DE;
Alois Biebl, Sankt Johann, DE;
Abstract
A drive circuit for an LED array comprises a first LED cluster and at least one second LED cluster. A control loop is designed to drive a switch of the first LED cluster so as to achieve a constant mean value of the current (I) flowing through the first LED cluster the control loop being designed for also driving switches of the further LED clusters. The drive circuit also comprises a total current detection device (R) with the aid of which it is possible to determine an actual magnitude (U) which corresponds to the sum of the currents through at least two of the second LED cluster. A comparison unit compares the actual magnitude (U) with a predefinable desired magnitude (U)