Multi-Frequency Fire Alarm Sounder

摘要

An audible output device, of a type usable in a fire alarm system, incorporates a multi-frequency waveform 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.