Patent ID: 9055639
Filing Date: 2015-06-09
Classification: H05B

Abstract:
1. An apparatus for driving a plurality of LED-based lighting units, comprising: a plurality of LED-based lighting segments connected in series, each of said LED-based lighting segments having a positive end and a negative end, and including at least one LED-based lighting unit connected in series; an input voltage supply coupled to the positive end of a first segment of said LED-based lighting segments; a current control device having a first end connected to the negative end of a last segment of said LED-based lighting segments and a second end connected to ground; a plurality of switch controllers, each of said switch controllers being connected in parallel with one corresponding segment of said LED-based lighting segments, each of said switch controllers receiving an input propagation signal and generating an output propagation signal; a switching voltage comparator unit receiving said input voltage supply, generating and sending a plurality of common signals to each of said plurality of switch controllers, and generating a first propagation signal as the input propagation signal of a first switch controller of said plurality of switch controllers; wherein the input propagation signal of each switch controller except for the first switch controller is the output propagation signal of an immediately preceding switch controller, each switch controller includes a switching device for short-circuiting the corresponding LED-based lighting segment, said switching device is controlled according to the input propagation signal of the switch controller, and the output propagation signal of each switch controller is derived from the input propagation signal of the switch controller and said common signals.