IT1240570B - Anti-intrusion system - Google Patents

Abstract

The invention concerns an anti-intrusion system comprising a central monitoring device that controls one or more peripheral devices composed of at least a container having a window to permit entry of infrared radiation coming from the environment and/or a possible intrusion where the central device evaluates in different ways the signals received from the peripheral device, according to which the system is either in the active functioning or standby state. The principal characteristic consists of the fact that even when the central monitoring device is in the standby state a second electronic circuit contained in each of the peripheral devices generates an alarm signal as a result of an attempt to tamper with at least one of these peripheral devices, owing to the fact that they comprise means of detection of tampering that analyse time variations of output signals from the detector outlet which already supplies the first signal to the first electronic circuit 2, 3, 4, 5, 6, 13 and if these are in a range of different values related to variations of the environment subject to monitoring they generate the alarm signal concerning the tampering attempt. <IMAGE>