| 摘要 |
PURPOSE:To provide a discharge lamp lighting device which does not cause malfunction of a protective circuit and can avoid problems such as lighting off even when the device is used under a bad power supply environment. CONSTITUTION:A reset circuit 8 indirectly detects drop of DC voltage connected to an inverter circuit 1, and a detected voltage is compared with a reference voltage to invert an output when the detection voltage becomes the reference voltage or less. A reset circuit 9 also detects drop of the DC voltage connected to the inverter circuit 1, so an output is inverted when the detected voltage is the reference voltage or less and in case it continues for a predetermined period or more. The output of the reset circuit 8 resets a discharge lamp voltage detection circuit 4 and an overcurrent detection circuit 5 to return them to initial conditions. In the meanwhile, the output of the rest circuit 9 triggers a monostable multivibrator M, and controls a generation part 2 to actuate the inverter circuit 1 from a preheatig mode by its Q output similarly to when power is charged. |
