| 摘要 |
PURPOSE:To start it softly and efficiently by supplying DC output from a rectifying circuit to an inverter through a resistance so as to preheat a discharge lamp filament by the output of the inverter which does not reach the discharge start voltage for a short time before a thyristor becomes ON after power ON, and then turning on the thyristor. CONSTITUTION:Though a commercial AC power source 1 is closed so as to start the oscillation of an inverter consisting of transistors 5 and 6 by the output of a rectifying circuit, a capacitor 25 is not charged yet immediately after the closing of the power source, and a DIAC 23 is in OFF condition. Accordingly, a thyristor 22 is also in OFF condition, and high frequency signals from a oscillation transistor 20 do not reach the discharge start voltage of a discharge lamp 9, and it simply preheats a filament 10. After that, if a certain time pass away, the capacitor 25 is charged, and the DIAC 23 becomes ON condition and the thyristor becomes ON, and the high frequency signals from the transformer 20 become high voltage and join in the filament 10 of a discharge lamp 8, and the discharge of the discharge lamp 8 becomes continuous conditions. |
