| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting system capable of surely re-starting a discharge lamp. SOLUTION: When a power source circuit is turned on and voltage of commercial AC power source (e) is detected with a voltage monitoring circuit 23, a timer circuit 24 outputs a pulse for several seconds. A light emitting diode LED emits light by the pulse output, a photo triac Q2 is turned on and a triac Q1 is turned on, a capacitor C1 is charged, a constant voltage element Z1 is turned on, voltage is raised with a coil L1, a pulse is supplied to a high intensity discharge lamp 9, and the high intensity discharge lamp 9 starts lighting. When the high intensity discharge lamp 9 puts out lights, lamp current does not flow, current is not detected with a current detecting circuit 25, and no lighting of the high intensity discharge lamp 9 is detected with a lighting judging circuit 26. The timer circuit 24 stops pulse output for several seconds enough to cool the high intensity discharge lamp 9, then outputs a pulse, applies high voltage to the high intensity discharge lamp 9 to surely re-starts the high intensity discharge lamp 9. |
