Patent ID: 8907583
Filing Date: 2014-12-09
Classification: H05B

Abstract:
1. A light emitting diode (LED) driving device for driving a number (M) of LED units coupled in series, each of the LED units having an input end and an output end, said LED driving device comprising: a rectifying circuit adapted to be coupled between an alternating current (AC) power source and the input end of a first one of the LED units for receiving an AC input voltage from the AC power source, said rectifying circuit rectifying the AC input voltage to a direct current (DC) voltage; a number (M−1) of first switching circuits, each of which is adapted to be coupled between the output end of a corresponding one of first to (M−1) a second switching circuit adapted to be coupled between the output end of an M a resistor unit coupled among said first switching circuits, said second switching circuit and ground; wherein, when the DC voltage from said rectifying circuit is sufficient to turn on the first to k the output end of a k the output end of each of first to (k−1)