| 摘要 |
PURPOSE:To provide a discharge lamp lighting device capable of lighting a discharge lamp as usual even a part is thinned out of plural discharge lamps. CONSTITUTION:When all fo fluorescent lamps FL1, FL2, and FL3 are connected, an inverter circuit 13 is controlled by a current transformer CT according to normal saturation. When any one of the fluorescent lamps FL1, FL2, and FL3 is demounted, a transistor Q3 is turned on and transistors Q5 and Q6 are turned off to store charge in a capacitor C16, and the saturation time of the current transformer CT is prolonged and the saturation time of the current transformer CT is corrected to be longer to light connected two out of the fluorescent lamps FL1, FL2, and FL3 at usual brightness. When two of the fluorescent lamps FL1, FL2, and FL3 are demounted, a Zener diode ZD1 is turned on and the point between the gate and source of an electric field transistor Q2 is short-circuited to stop the invertor circuit 13. |
