US3704447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Remote to central monitoring system utilizing amplitude coding of signals
Assignee: Individual
•
Filing: 1971-03-01
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Granted: 1972-11-28
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Expires: 1991-03-01
Abstract
Abstract A monitoring system includes a plurality of sensing stations for sensing and transmitting signals representing abnormal conditions to a central station through a single channel or line. The central station includes a plurality of detectors responsive to receive signals from the sensing stations and to identify one or more of the stations transmitting the signals.
Inventors
- 👤 Charles T Reader
- 👤 John F Renz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:27
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/018
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
207 words
In combination, a plurality of sensing devices located at spaced remote stations, said sensing devices being responsive to changes in conditions to generate single pulse amplitude modulated signals of predetermined different amplitudes, each one of said sensing devices being responsive to generate only a single pulse signal of a predetermined amplitude different in amplitude than the amplitudes of all of the others of said sensing devices, a plurality of detector circuits located at a central station, means for biasing said detector circuits to respond to single pulse signals of predetermined different amplitudes, each of said detector circuits being responsive to a single pulse amplitude modulated signal generated by a corresponding one of said sensing devices, a single signal line for transmitting a pulse signal from any one of said sensing devices to said central station to cause a corresponding one of said detector circuits to become activated to indicate a change in condition at a corresponding sensing device while all of the other of said detector circuits are maintained inactivated, and means to enable any one or more of said detector circuits maintained inactivated to become activated by single pulse signals generated to said central station after the activation of said corresponding one of said detector circuits.
Claim 2
Dependent Claim
207 words
In combination, a plurality of sensing devices located at spaced remote stations, said sensing devices being responsive to changes in conditions to generate single pulse amplitude modulated signals of predetermined different amplitudes, each one of said sensing devices being responsive to generate only a single pulse signal of a predetermined amplitude different in amplitude than the amplitudes of all of the others of said sensing devices, a plurality of detector circuits located at a central station, means for biasing said detector circuits to respond to single pulse signals of predetermined different amplitudes, each of said detector circuits being responsive to a single pulse amplitude modulated signal generated by a corresponding one of said sensing devices, a single signal line for transmitting a pulse signal from any one of said sensing devices to said central station to cause a corresponding one of said detector circuits to become activated to indicate a change in condition at a corresponding sensing device while all of the other of said detector circuits are maintained inactivated, and means to enable any one or more of said detector circuits maintained inactivated to become activated by single pulse signals generated to said central station after the activation of said corresponding one of said detector circuits.
Claim 3
Dependent Claim
26 words
The invention as set forth in claim 1, wherein said plurality of detector circuits are threshold level detectors normally held activated by different level bias voltages.
Claim 4
Dependent Claim
41 words
The invention as set forth in claim 2, wherein said threshold level detectors are operatively connected to each other with the different level bias voltages applied to said detectors progressivelY varying from one detector to the next detector in ascending order.
Claim 5
Dependent Claim
47 words
The invention as set forth in claim 3, wherein the pulse signal applied to said threshold level detectors activates the one of said detectors having the highest bias voltage level below the level of said pulse signal, with all of the other of said detectors remaining inactivated.
Claim 6
Dependent Claim
49 words
The invention as set forth in claim 4, wherein the detector activated generates an inhibit signal to prevent the activation of all the detectors having lower bias voltages than the bias voltage of said activated detector, with detectors having higher bias voltages than the applied pulse signal remaining inactivated.
Claim 7
Dependent Claim
29 words
The invention as set forth in claim 5, wherein the detector having the lowest bias voltage generates an alarm signal when said pulse signal is received by said detectors.
Claim 8
Dependent Claim
32 words
The invention as set forth in claim 6, wherein an indicator light is associated with each of said detectors and normally responsive to become lit upon the activation of its associated detector.
Claim 9
Dependent Claim
43 words
The invention as set forth in claim 7, wherein a memory circuit is provided in each of said detectors to maintain one or more of said activated detectors in active states without any of the indicator lights associated with said detectors becoming lit.
Claim 10
Dependent Claim
36 words
The invention as set forth in claim 8, wherein switching means are provided in said detectors to selectively render the lights associated with said detectors responsive or non-responsive without affecting the operating states of said detectors.
Claim 11
Dependent Claim
31 words
The invention as set forth in claim 9, wherein an additional detector is provided which is responsive to a tamper or fault in said signal line to produce an alarm signal.
Claim 12
Dependent Claim
141 words
A decoder circuit comprising a plurality of detector circuits, means for biasing to different bias levels to normally maintain said detector circuits inactivated, a plurality of sources for generating single pulse signals of different amplitudes, each of said sources generating a single pulse signal of an amplitude for activating a corresponding one of said detector circuits, means for applying said single pulse signals to all of said detector circuits, a single applied pulse signal from one of said sources causing a corresponding one of said detector circuits to become activated while all of the other of said detector circuits are maintained inactivated, and means to enable any one or more of said detector circuits maintained inactivated to become activated by another single pulse signal applied to all said detector circuits after the activation of said corresponding one of said detector circuits.
Claim 13
Dependent Claim
141 words
A decoder circuit comprising a plurality of detector circuits, means for biasing to different bias levels to normally maintain said detector circuits inactivated, a plurality of sources for generating single pulse signals of different amplitudes, each of said sources generating a single pulse signal of an amplitude for activating a corresponding one of said detector circuits, means for applying said single pulse signals to all of said detector circuits, a single applied pulse signal from one of said sources causing a corresponding one of said detector circuits to become activated while all of the other of said detector circuits are maintained inactivated, and means to enable any one or more of said detector circuits maintained inactivated to become activated by another single pulse signal applied to all said detector circuits after the activation of said corresponding one of said detector circuits.
Claim 14
Dependent Claim
26 words
A decoder circuit as set forth in claim 11, wherein said detector circuits include indicator means to permit identification of the source, transmitting single pulse signals.
Claim 15
Dependent Claim
52 words
A decoder circuit as set forth in claim 12, wherein said detector circuits are operatively connected to each other with the applied bias levels applied to said detector circuits being in an ascending progressive order so that any applied pulse signal falls between the bias levels of two of said detector circuits.
Claim 16
Dependent Claim
37 words
A decoder circuit as set forth in claim 13, wherein the detector circuit activated produces an inhibit signal to inhibit the detector circuits having lower bias levels with the detector circuits having higher bias levels remaining inactivated.
Claim 17
Dependent Claim
20 words
The invention as set forth in claim 14, wherein a memory circuit is provided in each of said detector circuits.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-28 | 1976-05-29 | 1976-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-28 | 1980-05-29 | 1980-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-28 | 1984-05-29 | 1984-11-28 | $7700.00 | Window Closed / Lapsed |