Patent ID: 6351079
Filing Date: 2002-02-26
Classification: H05B,Y10S

Abstract:
A lighting device comprising:a cluster of WLEDs, at least some of which WLEDs are chained in parallel between a pair of lines that apply a voltage across the WLED chains; first current altering means that can be controlled to alter the total current delivered to the individual WLED chains; second current altering means provided in each WLED chain, the second current altering means being controllable to alter the current flow in that WLED chain; current measuring means in each WLED chain; and control means communicating with the current measuring means within in each WLED chain, the control means being capable of controlling at least one of (i) the first current altering means and (ii) at least one of the second current altering means in response to variations in measured current in the individual WLED chains.