| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of reducing a power loss and preventing undue stress from being applied to a switching element, etc., by surely detecting an abnormal state such as no load and the breaking of a filament of a discharge lamp. <P>SOLUTION: The device comprises a serial connection of switching elements Q1, Q2; a capacitor C4 for cutting a DC component; a charging circuit for a smoothing capacitor C1 composed of a serial connection of a resistor R1 and a switching element Q3; an oscillating circuit 2; an initiating circuit 1; and a serial connection of a capacitor C2, an inductance element L2 and a load. When an output voltage from a rectifier DB becomes lower than a charging voltage for the capacitor C1, the charging voltage for the capacitor C1 becomes a partial smoothing power source for an invertor circuit composed of the switching elements Q1, Q2, etc. A control voltage Vcc applied through a current limiting element R5 is shut off by a switching element Q4 before the starting of oscillations of the switching elements Q1, Q2. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
