| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge-lamp lighting device capable of surely producing a start voltage. SOLUTION: When a transistor Q1 is turned on by a control circuit 5, current flows through a capacitor C2, and through a first inductor L1, a second inductor L2, and a primary winding Tr1a of an inverter transformer Tr1, whereby voltage is induced in a secondary winding Tr1b and a detection winding Tr1c of the inverter transformer Tr1, respectively. A fluorescent lamp FL is high-frequency lit based on the voltage induced in the secondary winding Tr1b by parallel resonance of the capacitor C2, the first inductor L1, the second inductor L2, and the primary winding Tr1a of the inverter transformer Tr1. The voltage induced in the secondary winding Tr1b is produced in a resistor R2 by way of the detection winding Tr1c, this voltage is detected by a detection circuit 7, the voltage of the resistor R2 is kept constant by the control circuit 5 if an inductance circuit 4 for resonance, the capacitor C2 for resonance, a capacitor C3, and other components have dispersion in their values, whereby voltage applied to the fluorescent lamp FL is kept constant, and thus its starting and lighting are made certain. |
