| 摘要 |
PURPOSE:To prevent the breakage of the transistor of a starting circuit by connecting a series body formed of a resistance and a serge absorber between the collector terminals and emitter terminals of the transistor. CONSTITUTION:A closed circuit is formed of an AC power source 1, a stabilizer 2, and a fluorescent lamp 3. A noise preventing capacitor 4 is connected to both the ends of the fluorescent lamp 3, and the collector terminal and emitter terminal of a transistor 13 having a base circuit for conducting switching by a timer circuit formed of a resistance 6 and an electrolytic capacitor 8 are connected to the non-power source side preheating electrode terminals of the fluorescent lamp 3 through a diode 5. A series body formed of a resistance 14 and a serge absorber 15 is connected between the collector terminal and emitter terminal of the transistor 13. Thus, even if the transistor is turned off and an excessive kick voltage is generated, the rated voltage or more of the transistor 13 is clipped by the resistance 14 and the serge absorber 15. Hence, the breakage of the transistor of a starting circuit can be prevented. |
