| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of appropriately controlling an inverter circuit even when the output voltage of a direct current voltage source by restraining heat radiation of parts or the like. <P>SOLUTION: At lighting under light control, a light control signal turns off a transistor Q2 for L-level, and a boosting chopper circuit 14 outputs with low voltage for the lighting under light control, in order to set the output voltage to be detected by the chopper control IC 16 by the divided voltage of resistor R5, and resistors R6, R7. A high frequency alternating current voltage is impressed on the fluorescent lamp FL in a state of lighting under light control with a voltage lower than the voltage at full lighting, and the fluorescent lamp FL is lighted under light control. A field effect transistor Q5 is turned into off-state by the light control signal, and the capacity of a snubber circuit 26 for supplying power to an inverter control IC 23 gets large since it gets into such a state that a snubber capacitor C8 is connected to a snubber capacitor C9 in parallel. The inverter circuit 21 supplies an appropriate current to the inverter control circuit, and operates in normal state even if the inverter circuit is made to operate in a prescribed frequency. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
