Patent ID: 8410711
Filing Date: 2013-04-02
Classification: H05B,Y02B

Abstract:
1. A controller for controlling power to a light-emitting diode (LED) light source which receives a DC voltage, wherein said LED light source comprises a first plurality of LEDs and a second plurality of LEDs, and wherein said controller is operable for turning on said first plurality of LEDs and turning off said second plurality of LEDs if a signal indicative of said DC voltage is within a predetermined range, and for turning on both said first plurality and said second plurality of LEDs if said signal indicative of said DC voltage is beyond said predetermined range, said controller comprising: a first switch coupled to said first plurality of LEDs; a second switch coupled to said second plurality of LEDs; wherein said first switch is controlled linearly and said second switch is turned off if said signal indicative of said DC voltage is within said predetermined range, wherein said first switch is turned off and said second switch is controlled linearly if said signal indicative of said DC voltage is beyond said predetermined range, and a comparator for comparing said signal indicative of said DC voltage to a predetermined reference signal, wherein said first switch and said second switch are controlled according to an output of said comparator.