Door or window lock has built in alarm detector in form of a reed relay switch that is operated by the presence of permanent magnet in movable lock element

摘要

The security device is installed in a drilled hole [5] in a door or window frame [6]. A movable sleeve [1] contains a security switch [3] that is a reed relay device. When the lock [12] is operated a small permanent magnet [24] moves to cause the switch to be active. Further movement of the lock is taken up by an over run spring [21] in the main cylinder [4].