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.

Date of Patent:
Mar. 07, 2017

Filed:

Oct. 25, 2013
Applicant:

Cree, Inc., Durham, NC (US);

Inventor:

Everett Bradford, Apex, NC (US);

Assignee:

Cree, Inc., Durham, NC (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0827 (2013.01); H05B 33/083 (2013.01);
Abstract

A lighting device employs at least one string of LEDs as a lighting source. The string of LEDs may be coupled in series between a power supply node and ground. In order to accurately determine a drive current running through or drive voltage across the string of LEDs, the drive current through the string of LEDs or the drive voltage across the string of LEDs is sampled randomly or semi-randomly, and a moving average is determined from each one of the samples. By sampling the drive current through or drive voltage across the string of LEDs randomly or semi-randomly, inaccuracies due to synchronization of the sampling with interference in the drive current signal or the drive voltage signal are effectively prevented. Accordingly, an accurate measurement of the drive current through or the drive voltage across the string of LEDs may be obtained.


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