Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
DRIVING LEDS WITH RESONANCE INDUCTOR AND CAPACITORS
Document Type and Number:
WIPO Patent Application WO/2011/030258
Kind Code:
A3
Abstract:
A drive circuit (DR) drives a plurality of LED strings (DS1, DS2; DS10) each comprising at least one LED (Di). The drive circuit comprises a resonance inductor (K1), and a plurality of branches which each comprise a series arrangement of a resonance capacitor (C31, C32; C34, C35) and an associated one of the plurality of LED strings (DS1, DS2; DS10). The resonance capacitor (C31, C32; C34, C35) is arranged between the resonance inductor (K1) and its associated one of the plurality of LED strings (DS1, DS2; DS10) to receive a resonance voltage (VAC) from the resonance inductor (Kl). A level and frequency of the resonance voltage (VAC) and an impedance of the resonance capacitor (C31, C32; C34, C35) are selected to obtain a current source supplying a LED current (IL1, IL2; IL10) through the associated one of the plurality of LED strings (DS1, DS2; DS10) which is substantially independent on a tolerance on forward voltages of LED' s of the associated one of the plurality of LED strings (DS1, DS2; DS10).

Inventors:
DECRAEMER ALAIN (BE)
DE MEERSMAN ERIK (BE)
Application Number:
PCT/IB2010/053939
Publication Date:
August 11, 2011
Filing Date:
September 02, 2010
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
KONINKL PHILIPS ELECTRONICS NV (NL)
DECRAEMER ALAIN (BE)
DE MEERSMAN ERIK (BE)
International Classes:
H05B44/00
Domestic Patent References:
WO2003056878A12003-07-10
WO2008110978A12008-09-18
Foreign References:
EP1791398A12007-05-30
EP1788850A12007-05-23
Attorney, Agent or Firm:
COOPS, Peter et al. (P.O. Box 220, AE Eindhoven, NL)
Download PDF:
View/Download PDF      PDF Help



 
Previous Patent: X-RAY APPARATUS

Next Patent: APPARATUS COMPRISING AT LEAST TWO POLARISED ELECTRICAL LOADS AND ELECTRIC CONNECTION CABLE FOR SUCH ...