| 摘要 |
PURPOSE:To prevent an oscillation from stopping at a heavy load time by providing a resonator, and providing a capacitor between a feedback winding and a transistor. CONSTITUTION:Before starting a fluorescent lamp of a load L, a load voltage is high, and a discharging circuit 10 operates. Accordingly, the stored charge of a capacitor C2 is rapidly discharged through a resistor R2 and a switching element S2 during the OFF period of a transistor Tr. Since the discharging circuit 10 operates even if the load L is fired so that the induced voltage of a feedback winding nf becomes low, the transistor Tr can be turned ON, and the oscillation will not stop. The discharging circuit 10 has detecting winding nD closely coupled in the output winding n2 of a transformer T, a diode D2 for rectifying the output of the winding nD, switching elements S1, S2, and resistors R3-R5, and the resistor R3 decides the discharging time constant of the capacitor C2. |
