Smoke alarm monitoring and testing system and method
First Claim
1. A method of monitoring and testing the integrity of a smoke detection and alarm system in which the smoke alarms are powered by a primary power supply, each smoke alarm having a stand-by battery power supply and being operable in a self-test mode, an alarm mode and a quiescent mode, the current drain in self-test and alarm modes exceeding the quiescent current drain, said method including:
- switching the voltage supplied to the smoke alarms such that when the smoke alarms are in quiescent mode, the current drain is via the primary power supply, if available, and not via the stand-by battery power supply.
1 Assignment
0 Petitions
Accused Products
Abstract
A smoke detection and alarm system including one or more low cost battery operated smoke alarms fitted with internal non-rechargeable standby batteries, a reactive primary power supply derived from mains supply, and connecting means for connecting the reactive power supply to each of the system'"'"'s smoke alarms, the system being characterized in that said reactive primary power supply comprises: means for providing a DC supply of slightly higher than the smoke alarm standby battery voltage; and means for detecting the higher than quiescent current supplied by the reactive power supply when any of the smoke alarms connected as part of the system is in alarm or in self-test mode; and means of lowering the DC supply voltage made available to power the system'"'"'s smoke alarms when a higher than quiescent current is detected; and said smoke alarms comprise: means by which all the current required under quiescent condition, with primary power available, is supplied by the reactive primary power supply; and means by which a very high proportion of the current required when any of the system'"'"'s smoke alarms is in self-test mode is supplied by the smoke alarm battery as the DC voltage of the reactive primary power supply drops in self-test mode; and all of the above system'"'"'s characteristics resulting in: the condition of the standby battery of each smoke alarm being tested at regular intervals to provide an audible warning if the battery is depleted, disconnected or missing; and the standby battery of each smoke alarm supplying quiescent current only for very brief periods to result in the standby batteries having a longer life well in excess of the average one year life common with existing systems; and the system being of very low overall cost and of much improved reliability.
31 Citations
27 Claims
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1. A method of monitoring and testing the integrity of a smoke detection and alarm system in which the smoke alarms are powered by a primary power supply, each smoke alarm having a stand-by battery power supply and being operable in a self-test mode, an alarm mode and a quiescent mode, the current drain in self-test and alarm modes exceeding the quiescent current drain, said method including:
switching the voltage supplied to the smoke alarms such that when the smoke alarms are in quiescent mode, the current drain is via the primary power supply, if available, and not via the stand-by battery power supply. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A smoke detection and alarm system including:
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a primary power supply; a plurality of smoke alarms powered by said primary power supply, each smoke alarm having a stand-by battery power supply and being operable in a self-test mode, an alarm mode or a quiescent mode, the current drain in self-test and alarm modes exceeding the quiescent current drain, and switching means for switching the voltage supplied to the smoke alarms such that when the smoke alarms are in quiescent mode, the current drain is via the primary power supply, if available, and not via the stand-by battery power supply. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A smoke detection and alarm system including one or more low cost battery operated smoke alarms fitted with internal non-rechargeable stand-by batteries, a reactive primary power supply derived from mains supply, and connecting means for connecting the reactive primary power supply to each of the system smoke alarms, the system being characterised in that
(1) said reactive primary power supply comprises: -
(a1) means for providing a d.c. supply of slightly higher voltage than the smoke alarm stand-by battery voltage, and (a2) means for detecting the higher than quiescent current supplied by the reactive primary power supply when any of the smoke alarms connected as part of the system is in alarm or self-test mode, and (a3) means of lowering the d.c. supply voltage made available to power the system smoke alarms when a higher than quiescent current is detected; and (2) said smoke alarms comprise; (b1) means by which all the current required under quiescent condition, with primary power available, is supplied by the reactive primary power supply, and (b2) means by which a very high proportion of the current required when any one of the system smoke alarms is in self test mode is supplied by the smoke alarm battery as the d.c. voltage of the reactive primary power supply drops in self test mode; and (3) all the above system characteristics resulting in; (c1) the condition of the stand-by battery of each smoke alarm being tested at regular intervals to provide an audible warning if the battery is depleted, disconnected or missing, and (c2) the stand-by battery of each smoke alarm supplying current only for very brief periods to result in the stand-by batteries having a longer life well in excess of the average one year life common with existing systems; and (c3) the system being of very low overall cost and of much improved reliability.
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Specification