| 摘要 |
PURPOSE: To provide a simplified control circuit with no control circuit for a dimmer by receiving power from between operation cycles through a control terminal of the dimmer. CONSTITUTION: A control circuit is connected to between terminals 113, 114. A light sensor LS for detecting surrounding light is connected across the terminals of a capacitor C, and one end of the capacitor is connected to a base of an NPN transistor Q3 . Electric power for operating transistors Q1 , Q2 , Q3 is supplied from a control circuit for a dimmer of a fluorescent lamp connected to a ballast 31. The transistor Q3 serves as a light amplifier. The transistor Q2 is operated as a control amplifier, and also operated as a current sink. The transistor Q1 is a main current sink. The ballast 31 supplies sufficient operating voltage and current to between the terminals 113, 114 to operate the transistors Q1 , Q2 , Q3 . |
