| 摘要 |
PURPOSE:To protect elements from breakdown by connecting a time constant circuit to the output side of a control circuit and performing control of ON interval slowly. CONSTITUTION:Lighting device for discharge lamp LT is constituted with a self-exciting transistor inverter circuit having a resonance circuit at the secondary which comprises a rectifying circuit REC for AC power source, a leakage transformer TR, a main switching element Q1, and the like. A time constant circuit comprising a resistor R18 and a capacitor C19 connected in series is connected between a control transistor Q2 and an ON interval control transistor Tr. By such arrangement, ON interval of the element Q1 can be performed slowly upon application of surge. |
