| 摘要 |
PURPOSE:To provide a discharge lamp lighting device detecting the abnormal state such as the failure of a discharge lamp with a simple structure. CONSTITUTION:When the filament FLa of a discharge lamp FL is not fitted, an electric closed circuit 26 is not formed, a transistor Q4 is turned on, the detected voltage is the lowest, and a control means 25 stops the output of an inverter circuit 24. When the filament FLb of the discharge lamp FL is not fitted, an electric closed circuit 27 is not formed, no voltage is applied to a resistor R5, and the control means 25 stops the output of the inverter circuit 24. When the rated voltage of the commercial AC power source E is lower than the preset value, the voltage divided by resistors R3, R6 is made the preset value or below, the transistor Q4 is turned on, the voltage detected by a filament installation detecting means 28 is reduced, and the control means 25 stops the output of the inverter circuit 24. |
