| 摘要 |
PURPOSE:To provide a lighting equipment which can start discharge lamp easily and in which the discharge lamp is hard to blackening. CONSTITUTION:When a power is turned on, and a filament FLa side is a positive electrode, a Zener diode ZD2 maintains reverse blocking condition and a transistor Q1 keeps off condition, as electric charge is not accumulated in a capacitor C2 of a timer circuit 3. Voltage of resistors R1 and R2 divided by resistors R1, R2, R3 and R4 is applied to a Zener diode ZD1, the Zener diode ZD1 is turned on, a current is supplied to a gate of a thyristor Th, the thyristor Th is turned on, and filaments FLa and FLb are preheated. After a certain amount of time has passed and a capacitor C1 is charged, oscillation starts to illuminate the discharge lamp FL. |
