| 摘要 |
PURPOSE:To automatically switch off a lamp in light daytime to prevent a loss. CONSTITUTION:A CdS 9 for outputting a signal according to the circumferential brightness is used. The resistance value of the CdS 9 is changed according to the circumferential brightness. Thus, the illuminance of a lamp 18 is also changed according to the changed resistance value of the CdS 9. When the circumference is light in the daytime, the lamp 18 is extinguished to prevent a loss. |
