| 摘要 |
PURPOSE:To continue illumination control without a further operation of a switch after an indoor switch operation to turn off a light by closing an illumination circuit when illuminance becomes equal to or lower than a specified value, and opening the illumination circuit by an instantaneous cutoff of a power source in an illuminance state lower than the specified value. CONSTITUTION:A period from an instantaneous cutoff of a power source to generation of a detection signal in an illuminance detecting means, during generation of the detection signal in the illuminance detecting means consisting of a combination of an illuminance sensor 40 and a comparator 41, is detected by a period detecting means (logic circuit) comprising a combination of a D-type flip-flop 50 and an AND gate 51, and for that period an illumination lamp is controlled to be in an off state. Accordingly, in the case of going to bed and the like an instantaneous operation of on-off-on of an indoor switch 2 turns off the illumination lamp and in the morning an increase of an outside light reverses an output of a comparator 41 to a low level. In the evening, the output of the comparator 41 is reversed to a high level to turn on the illumination lamp. According to this constitution, even when the operation of the indoor switch 2 turns off the illumination lamp temporarily, illumination control can be continued. |
