| 摘要 |
PURPOSE:To prevent the discharge stop by the unstable current in the initial stage of lighting by setting the number of turns of the secondary side winding of a transformer to two different values, and controlling discharge starting voltage, steady voltage and middle voltage with a small rated part. CONSTITUTION:For the number of turns of the secondary windings N2, N3 of a transformer T1, that of the winding N3 is larger. Just after power source input, the high voltage form the winding N3 is supplied to an igniter through a rectifying circuit formed of diodes D1, D2 and a smoothing circuit consisting of a resistor R1, a capacitor C1, a resistor R2, and a capacitor C2, and the discharge lamp lighting voltage of a lamp is controlled. The lamp impedance for starting discharge is lowered, and the igniter is stopped. The voltage of the winding N2 is increased, middle voltage and steady voltage are controlled to steadily drive the lamp, and the discharge stop by the unstable current in the initial stage of lighting is prevented with a miniature and simple structure using a small rated part, and the lamp is steadily driven. |
