Remote alarm system
First Claim
1. A remote alarm system, comprising:
- a transmitter;
circuit means, included in said transmitter for generating an audio frequency electrical signal;
means for activating said circuit means for generating;
modulator circuit means, included in said transmitter and coupled to said circuit means for generating, for forming a current source modulated by said circuit means for generating;
radio frequency oscillator circuit means included in said transmitter and coupled to said modulator circuit means for being modulated by said modulated current source;
antenna means coupled to said radio frequency oscillator circuit means for transmitting signals therefrom;
a receiver;
antenna means for receiving transmissions from said antenna means for transmitting;
super-regenerative detector means included in said receiver and coupled to said antenna means for receiving;
amplifier means included in said receiver and coupled to said detector means for amplifying signals therefrom;
notch filter means included in said receiver and coupled to said amplifier means for selectively filtering the audio frequency of said circuit means for generating;
alternating current rectifier means included in said receiver and coupled to said filter means for converting any said audio frequencies filtered by said filter means into a direct current signal;
delay circuit means, included in said receiver and coupled to said rectifier means, for delaying activation of an alarm signal until said direct current signal is present for a predetermined amount of time and for determining a period of time for activation of an alarm signal; and
alarm means coupled to said delay circuit means for generating an alarm signal in response to said delay circuit means.
1 Assignment
0 Petitions
Accused Products
Abstract
A remote alarm system provides a transmitter having an audio frequency signal generator circuit, a modulator circuit forming a current source modulated by the audio frequency signal and a radio frequency oscillator circuit modulated by the current source, and a receiver having a super-regenerative detector, an amplifier connected thereto, a notch filter for selectively filtering the audio frequency signal, an alternating current rectifier for rectifying the audio frequency signal, a delay circuit for delaying activation of an alarm signal until a signal from the rectifier circuit is present for a predetermined amount of time and for determining a period of time for activation of an alarm signal, and an alarm means for generating an alarm signal in response to the output of the delay circuit.
12 Citations
8 Claims
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1. A remote alarm system, comprising:
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a transmitter; circuit means, included in said transmitter for generating an audio frequency electrical signal; means for activating said circuit means for generating; modulator circuit means, included in said transmitter and coupled to said circuit means for generating, for forming a current source modulated by said circuit means for generating; radio frequency oscillator circuit means included in said transmitter and coupled to said modulator circuit means for being modulated by said modulated current source; antenna means coupled to said radio frequency oscillator circuit means for transmitting signals therefrom; a receiver; antenna means for receiving transmissions from said antenna means for transmitting; super-regenerative detector means included in said receiver and coupled to said antenna means for receiving; amplifier means included in said receiver and coupled to said detector means for amplifying signals therefrom; notch filter means included in said receiver and coupled to said amplifier means for selectively filtering the audio frequency of said circuit means for generating; alternating current rectifier means included in said receiver and coupled to said filter means for converting any said audio frequencies filtered by said filter means into a direct current signal; delay circuit means, included in said receiver and coupled to said rectifier means, for delaying activation of an alarm signal until said direct current signal is present for a predetermined amount of time and for determining a period of time for activation of an alarm signal; and alarm means coupled to said delay circuit means for generating an alarm signal in response to said delay circuit means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification