Anti-burglary devices with alarm control, for security

摘要

Anti-burglary devices with alarm control for security, including a mechanical detection part and an electronic alarm control part. The mechanical part is characterised by an elastic fixing of the closures or of the objects to be protected, which makes temporary contact upon an attempt at illegal handling. The electronic part consists of a monostable followed by a relay. Voltage is applied to it via a temporary detection contact, and it is maintained in action for the programmed duration by a working contact of the relay. A second contact of the relay controls the alarm device. There is no sensitivity to interference and the consumption is zero in standby position. The figure gives an example embodiment: the mechanical device is here a lock with a movable bolt (1) held by springs (2). When pushed, the electrical contact (3) triggers the monostable (4) kept on by the relay (5) which controls the alarm (6). IMAGE