Security surveillance and fire detection system

摘要

A security system comprising a lamp 26 and/or siren 24 for attracting the attention of an intruder detected by passive infra-red detector 22 and/or 32 to a particular direction and an image capturing system 28 eg a camera, for capturing and recording the image of the intruder when attracted in said direction. The image capturing system 28 is activated upon receiving a 'detect' signal from the detector 22 and/or 32. The system may include a fire detection arrangement including a thermal sensor eg a positive temperature coefficient thermistor, and an alarm circuit having a mercury wetted relay whereupon the sensing of a predetermined temperature results in the thermal sensor acting to close the relay and actuate the alarm. The alarm may be located in a housing having a handle so positioned that lifting the housing by the handle results in the housing tilting and a tilt detector being actuated to thereby trigger the alarm eg sirens and/or lights. The system includes a plurality of relay stations each associated with a plurality of detector units, each detector unit transmitting information to its associated relay station by way of a radio signal and from there to a central control via a modem and a telephone line.