| 摘要 |
PROBLEM TO BE SOLVED: To improve security of a lighting control device of a vehicle lamp tool by preventing LED failure in a simple structure. SOLUTION: The lighting control device 1 for a vehicle lamp tool is provided with a switching regulator 2 to supply an LED current to an LED, an electric current sensing portion 4 to detect the LED current, and a control portion 3 to activate an LED light-control so that an average LED electric current is reduced through high-speed repetition of driving and shutdown of the switching regulator 2 in response to the light-control signal. The electric current sensing portion 4 is equipped with a capacitor C2 to hold the LED current detected during the driving period of the switching regulator 2 in a shutdown period after its driving period. COPYRIGHT: (C)2010,JPO&INPIT |
