| 摘要 |
<p>An intrusion detector (2) has a sensor (4) which is responsive to the vibration and tilting of an accessway, such as a door or window, brought about by the attempts of an intruder to gain entry to a premises. An alarm sounder (170) is activated when a sounder activation means (160) is triggered by trigger circuitry (6). The trigger circuitry (6) triggers on the detection of an intruder. A buffer (8) prevents spurious stimulation of the sensor (4) by wind buffeting, passing vehicular traffic etc. from causing the trigger circuitry (6) to trigger.</p> |
