LIGHTING DEVICE, AND ILLUMINATION FIXTURE HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a lighting device capable of controlling power consumption of a lamp LA on the basis of ripple voltage and extending life of an electrolytic capacitor C1. SOLUTION: The lighting device includes a power source rectifying circuit 20 for rectifying input AC voltage, a DC power source circuit 30 connected to the power source rectifying circuit 20 and having the electrolytic capacitor C1 which generates smooth voltage, a lighting circuit 40 connected to the electrolytic capacitor C1 and lighting up the lamp LA by converting to voltage corresponding to the lamp LA connected to the smooth voltage smoothed by the electrolytic capacitor C1, and a life detection circuit 50 connected to the electrolytic capacitor C1 in parallel and detecting ripple voltage of the electrolytic capacitor C1 and outputting a life level signal for reducing brightness of the lamp LA to the lighting circuit 40 when the detected ripple voltage is lower than a preset reference voltage L. Power consumption of the lamp LA can be controlled on the basis of the ripple voltage, and the life of the electrolytic capacitor C1 can be extended. COPYRIGHT: (C)2010,JPO&INPIT