Alarm system
First Claim
1. An alarm system comprising:
- at least two alarm detecting devices, each alarm detecting device comprising;
an alarm condition detecting circuit,a secondary alarm activation circuit, andan audible alarm output circuit including an audio oscillator and a speaker;
said audible alarm output circuit being responsive to a detecting circuit control output generated by said alarm condition detecting circuit and to a secondary triggering output signal generated by said secondary alarm activation. circuit;
said secondary alarm activation circuit including;
a microphone having a microphone output signal,an amplifier circuit in connection with said microphone output signal and generating an amplified output signal,a tunable filter circuit having a filter input in connection with said amplifier output signal, said tunable filter circuit generating a filtered output signal in a first predetermined frequency range, said tunable filter circuit including a tuning mechanism tunable by a user to set a desired said first frequency range;
a filter signal integrator having an integrator input in connection with said filtered output signal for integrating said filtered signal output and generating an integrated output signal;
a reference signal generator having a reference signal output;
a comparator circuit having a reference signal input in connection with said reference signal output and a compared signal input in connection with said integrated output signal, and generating said secondary alarm triggering output signal when said compared signal input exceeds said reference signal input.
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Abstract
An alarm system that includes a number of alarm detecting devices wherein each alarm detecting device includes an alarm condition detecting circuit, a secondary alarm activation circuit, and an audible alarm output circuit including an audio oscillator and a speaker; the audible alarm output circuit being responsive to a detecting circuit control output generated by the alarm condition detecting circuit and to a secondary triggering output signal generated by the secondary alarm activation circuit; the secondary alarm activation circuit including a microphone having a microphone output signal, an amplifier circuit in connection with the microphone output signal and generating an amplified output signal, a filter circuit having a filter input in connection with the amplifier output signal generating a filtered output signal in a first predetermined frequency range; a filter signal integrator having an integrator input in connection with the filtered output signal for integrating the filtered signal output and generating an integrated output signal; a reference signal generator having a reference signal output; a comparator circuit having a reference signal input in connection with the reference signal output and a compared signal input in connection with the integrated output signal, and generating the secondary alarm triggering output signal when the compared signal input exceeds the reference signal input.
106 Citations
1 Claim
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1. An alarm system comprising:
at least two alarm detecting devices, each alarm detecting device comprising; an alarm condition detecting circuit, a secondary alarm activation circuit, and an audible alarm output circuit including an audio oscillator and a speaker; said audible alarm output circuit being responsive to a detecting circuit control output generated by said alarm condition detecting circuit and to a secondary triggering output signal generated by said secondary alarm activation. circuit; said secondary alarm activation circuit including; a microphone having a microphone output signal, an amplifier circuit in connection with said microphone output signal and generating an amplified output signal, a tunable filter circuit having a filter input in connection with said amplifier output signal, said tunable filter circuit generating a filtered output signal in a first predetermined frequency range, said tunable filter circuit including a tuning mechanism tunable by a user to set a desired said first frequency range; a filter signal integrator having an integrator input in connection with said filtered output signal for integrating said filtered signal output and generating an integrated output signal; a reference signal generator having a reference signal output; a comparator circuit having a reference signal input in connection with said reference signal output and a compared signal input in connection with said integrated output signal, and generating said secondary alarm triggering output signal when said compared signal input exceeds said reference signal input.
Specification