| 摘要 |
PROBLEM TO BE SOLVED: To enable reduction of the cost, alleviation of a check work of the polarities of signal lines and reduction of the load imposed on a worker without any complicated microcomputer or the like.SOLUTION: A sensor device 100 for controlling a lighting state of a lighting device 200 has a sensor 10, a Dc power source 20 for converting power from an external power source to power for an operation, a pair of signal lines 30 used for connection to a sensor device of another lighting device, a current limiter 40 for connected between a positive electrode as one output terminal of the DC power source 20 and one of the pair of signal lines 30, a first switch 50 which is connected between a negative electrode as the other output terminal of the DC power source 20 and the other of the pair of signal lines 30 and turned on when the sensor 10 is operated, and a signal transmission unit 60 connected between the pair of signal lines 30. Current signals in both the directions between the pair of signal lines 30 are transmissible through a signal input terminal 60a of the signal transmission unit 60, and a signal output terminal 60b of the signal transmission unit 60 is connected through a first opening/closing device 70 between the positive and negative electrodes of the DC power source 20. |
