| 摘要 |
PURPOSE:To easily constitute a circuit capable of lighting a neon lamp with a sufficient brightness and setting the illuminance around the lighted neon lamp dark at a low cost. CONSTITUTION:A CdS 2 is connected between power sources through a current limit resistance R, and a series circuit of a bidirectional Zener diode ZD and a neon lamp 1 is connected in parallel to both ends of the CdS 2. The lighting voltage of the neon lamp 1 is apparently increased by the portion of the Zener voltage, and when the circumferential illuminance becomes dark, the neon lamp 1 is lighted. By enhancing the voltage applied to the neon lamp 1 at this lighting time, the neon lamp 1 is brightly lighted. As the Zener diode ZD is only added, the circuit constitution is simplified, and the cost is reduced. |
