| 摘要 |
Keyhole alarm system which is placed on the inner side of a door and consists of the shell (1) the siren (3) the electronic board (4) the switch - pushbutton (5) the battery (6) the switch (7) the shell (2) which includes an oblong section (10) which is placed from the inner side of the door, inside the keyhole, clogging up the exit. In an attempt to break the lock by inserting a tool in the keyhole, the oblong section moves (10) the main body of the alarm system inwards, away from the door and the switch - pushbutton (5), which was in a stand-by mode before the insertion, activates the siren. |
