| 摘要 |
PURPOSE:To obtain the optimum lighting control by outputting a human detection signal if a person exists in a detection region and the first control signal if not, outputting the second control signal on receiving the human detection signal, and turning a light on or off in response to the control signals. CONSTITUTION:When the illuminance in the detection region of a photosensor 11 is low and dark, an H-level low-illuminance detection signal is outputted from a comparator 13. If no person exists in the detection region of a human sensor 12 at this time, an H-level human detection signal is not outputted from the comparator 14, thus a set signal (second control signal) is not outputted from an AND circuit 18, an L-level current feed stop signal is outputted from FF5, a relay contact point 22a is kept opened, and a lighting fixture 1 is kept turned off. If a person enters the detection region of the sensor 12 when the circumference is dark, an H-level human detection signal is outputted from the sensor 12, an H-level set signal is outputted from the AND circuit 18, an H-level current feed command signal is outputted from FF19, and the lighting fixture 1 is lit. |
