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. 08, 2016
Filed:
Mar. 04, 2014
Bernhard Siessegger, Danvers, MA (US);
Benjamin Alexandrovich, Brookline, MA (US);
Bernhard Siessegger, Danvers, MA (US);
Benjamin Alexandrovich, Brookline, MA (US);
OSRAM SYLVANIA INC., Wilmington, MA (US);
Abstract
Techniques are disclosed for dimming LED strings using frequency modulation (FM) dimming and burst control dimming. At high brightness levels, FM dimming may be used to decrease the current through LED strings by increasing the switching frequency of pulses within a pulse train of an AC current source. At low brightness levels, or after the switching frequency has been increased to the resonant frequency of the current source, burst control dimming may decrease the current through LED strings by decreasing the duty cycle of the pulse train of the current source. At high brightness levels, FM dimming and burst control dimming may be combined by decreasing the duty cycle of the pulse train at each of a number of increasing switching frequency values. FM dimming may also be combined with frequency hopping in order to increase the number of available frequency steps.