Patent ID: 8508142
Filing Date: 2013-08-13
Classification: H05B

Abstract:
1. A portable lighting device comprising: a power source that is operable for providing a voltage; a load comprising a light emitting diode (LED) light source; and a controller that is operable for receiving said voltage and regulating a current of said LED light source based on a sensing signal indicating said voltage of said power source, wherein said controller is operable for regulating said current of said LED light source to a first current level if said sensing signal indicates that said voltage of said power source is greater than a first voltage level, wherein said controller is operable for regulating said current of said LED light source to a second current level if said sensing signal indicates that said voltage of said power source is less than a second voltage level, wherein said second voltage level is less than said first voltage level, and wherein said controller is operable for regulating said current of said LED light source to vary according to said sensing signal if said sensing signal indicates that said voltage of said power source is between said first voltage level and said second voltage level.