Patent ID: 8648537
Filing Date: 2014-02-11
Classification: H05B

Abstract:
1. An apparatus for driving LED-based lighting units, comprising: a plurality of LED-based lighting units, each of said LED-based lighting units having a positive terminal, a negative terminal and one or more LEDs connected between said positive and negative terminals; a plurality of switching units interleaved with said plurality of LED-based lighting units, each of said switching units being disposed between a corresponding leading LED-based lighting unit and a corresponding trailing LED-based lighting unit; an input voltage supply connected to said positive terminal of a first LED-based lighting unit of said plurality of LED-based lighting units; a controller for controlling said plurality of switching units; and a current control device having a first end connected to said negative terminal of a last LED-based lighting unit of said plurality of LED-based lighting units, and a second end connected to ground; wherein each of said plurality of switching units is separately controlled by said controller and comprises a series-connection mode for connecting said negative terminal of said corresponding leading LED-based lighting unit to said positive terminal of said corresponding trailing LED-based lighting unit, a parallel-connection mode for connecting the two positive terminals of the corresponding leading and trailing LED-based lighting units together, and the two negative terminals of the corresponding leading and trailing LED-based lighting units together, and a by-pass mode for connecting both said positive terminal and said negative terminal of said corresponding leading LED-based lighting unit to said positive terminal of said corresponding trailing LED-based lighting unit.