FLUORESCENT LAMP DRIVING CIRCUIT HAVING FUNCTION FOR CIRCUIT PROTECTION AND INDICATION OF THE END

摘要

PURPOSE: A fluorescent lamp operating circuit with a circuit protection function and a function which indicates that the lifetime of a lamp almost ends is provided to detect and display a lifetime end point of a fluorescent lamp, thereby protecting a stabilizer. CONSTITUTION: A lamp voltage detecting unit(110) detects a supply voltage in a fluorescent lamp. An initial stabilization unit(120) stabilizes an initial detection voltage when the fluorescent lamp is turned on. A reference voltage setting unit(130) sets a reference voltage for a detection voltage when the lifetime of the fluorescent lamp almost ends. A comparison unit(140) compares a supply voltage with the reference voltage and outputs a trigger signal to the lamp voltage detecting unit. A display and support current keeping unit(160) displays a lamp lifetime state and protects a stabilizer.