| 摘要 |
The invention relates to an alarm unit for detecting and identifying the crossing of one or more protected passages. Each peripheral station of the unit essentially comprises a first bistable circuit g2, one control input of which is connected to a reference potential via contacts k1-k4 associated with the protected passages, and a second bistable circuit g1, a control input of which is connected to a voltage source vg for placing the peripheral on alert, and an output of which is connected to the said input of the first bistable circuit g2 and a second input of which is connected to an output of this first bistable g2. The invention is applicable to the protection of premises. <IMAGE>
|
