| 摘要 |
PURPOSE:To simplify the work for wiring of 2 lines in parallel and the constitution of a curcuit by changing current consumption sharply at the time of operation of repeaters and a light receiver in an unlawful invasion monitoring system etc. CONSTITUTION:Projector 1, plural repeaters 2 and light receiver 3 are arranged in series against a projected luminous flux and the interrupted light between respective devices is detected by circuit 4 in the system. The system is constituted so that power is supplied from circuit 4 to each device by means of wiring 5 of 2 lines in parallel, and repeater 2 and light receiver 3 make the current consumption change sharpy at the time of receiving of luminous fluxes. The system equips level meter circuit 6 which divides the current of wiring 5 in every stage of the amount of current in circuit 4 and detects the current and makes LED 7 drive respectively according to the output of each stage, so that the operated device is discriminated. |
