LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a lighting system in which arc discharge is not continued even when the arc discharge is generated by a contact failure or the like. SOLUTION: A constant current high frequency power source 1 uses an AC power source AC as a power source to output high frequency waves. A load circuit 2 supplies power through a current transformer Tr connected to an output line W to a lamp La. When arc discharge is generated by a contact failure or the like on the output line W, a phase detection circuit detects arc discharge generated based on phase difference between a voltage phase and a current phase, and it stops an output of the constant current high frequency power source 1.