Multi-frequency fire alarm sounder
AssigneeHoneywell International Inc.
InventorsManley Keeler, Charles Fisler, Simon Ha
Life of this patent
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Abstract
An audible output device, of a type feasible in a fire alarm system, incorporates a multi-frequency wave form generator. The generator produces a plurality of frequencies with predetermined duty factors during various time intervals on a repetitive basis. The multi-frequency drive signal is in turn coupled to an audible output device such as a piezoelectric horn or the like. The multi-frequency audio output provides an indicator to persons adjacent to the device of the presence of an alarm condition.
Claims27
An alarm indicating output device comprising:
- an output transducer;
- a source of a plurality of different driving frequencies coupled to the transducer, the source includes circuits to sequentially couple members of the plurality of different frequencies, one at a time to the transducer during respective time intervals.
An audible output device comprising:
- an audible output transducer;
- and software for generating a sequence of driving signals for the transducer, the signals exhibiting a plurality of different frequencies with each frequency presented substantially solely, during a respective time interval, to the transducer.
A method of driving an audible output device comprising:
- providing an audible output device;
- establishing a set of output frequencies and associated output time intervals;
- repetitively coupling each of the frequencies for a respective time interval to the output device.
Dependencies are inferred from the claim text.