摘要 |
FIELD: intruder alarm signaling devices, possible use for guarding extensive areas of terrain, windows and doors of buildings, and also safes and other objects, using any conductive body as sensitive element. ^ SUBSTANCE: introduced into system are electrically changeable capacitor and inverting amplifier, while one output of electrically changeable capacitor is connected to one output of standard capacitor and through resistor - to first output of rectangular signal generator, another output of electrically changeable capacitor being connected to output of low frequencies filter. Input of low frequencies filter is connected to output of inverting amplifier, input of which is connected to output of storage-selection device, meant for connection to input of executive device with threshold block. ^ EFFECT: increased guarding system reliability and simplified installation of device on object being guarded. ^ 2 dwg |