| 摘要 |
PURPOSE:To decrease consumption of energy on a thermistor by actuating a thyristor which is controlled by a capacitor and diode AC switch when a fluorescent tube begins operating, and allowing the current to flow to a silicon rectifier. CONSTITUTION:Between an R/F circuit 10 and a high frequency switching circuit 30, a starting current limiting circuit 20 is installed through a loop including a thermistor 21 having a negative temp. coefficient. The thermistor 21 is connected parallel with a diode 25 installed facing oppositely to a thyristor 24, and the gate terminal of the thermistor is connected with a resistance 26 and a diode AC switch 23, to which a capacitor 22 is connected. The capacitor 22 is connected with the cathode of the thyristor 24 and a voltage dividing resistance 28 to constitute the starting current limiting circuit 20. When a fluorescent tube AB is going to start with a starter circuit 40, the current flowing through the filament of the fluorescent tube is controlled, and gradual increase is made by the thermistor 21. By the diode AC switch the thyristor is actuated to the capacitor 22, and the current flows through the thyristor 24. |
