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(11) | EP 1 035 528 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Fire alarm system |
(57) A fire alarm system comprises a control panel 13 and a plurality of combined smoke
detectors and sounders 10 connected to a wire extending from the control panel 13.
Each detector 10 is arranged to change from a standby condition to an alarm condition
when activated by smoke, however the control panel 13 is only arranged to trigger
the sounders 10 when the activated detector 10 has changed from its standby condition
to the alarm condition at least twice within a predetermined time period. In use, if the detector 10 was activated by smoke eg. from cooking, the smoke will diffuse quickly and the detector will not be activated again, and the sounders will not be triggered. However, if there is a real fire, the detector will be reactivated immediately and the sounders will be triggered. |