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US4331952A Expired / Lapsed US ⏱️ 0.0 years remaining

Redundant sensor adapter

Assignee: ADT Diversified Services Inc
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Filing: 1980-09-22
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Granted: 1982-05-25
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Expires: 2000-09-22
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Abstract

Abstract An adapter for a multiwire security and surveillance system which permits the connection of redundant sensors at one location, without affecting the operation of non-redundant sensors at other locations. In one embodiment each of the redundant sensors is coupled to the adapter, such that individual sensor alarm currents are prevented from being applied to the signal wire. In response to simultaneously occuring latched output signals from the redundant sensors, a circuit within the adapter couples to the signal wire the same type alarm condition signal which is provided by the individual sensors. A voltage driver/current sensor circuit is interposed between an associated redundant sensor and the signal line to both sense an alarm condition at the corresponding redundant sensor and to isolate the sensor from the signal line, with the adapter coupling control signals through the associated voltage driver/current sensor circuit to the associated redundant sensor.

Inventors

  • 👤 Aaron A. Galvin
  • 👤 Kevin D. Flynn

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 12:19
CPC Classifications
G; G08; G08B; G08B29/00; G08B29/16

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 158 words
Apparatus for a facility monitoring system having a multiwire interconnect cable which includes a signal line, said apparatus permitting the connection of redundant sensors at one location to the multiwire interconnect cable without affecting the operation of non-redundant sensors connected to the interconnect cable, comprising: an adapter module adapted to be coupled between the redundant sensors and the multiwire interconnect cable, said adapter module including means interposed between each of said redundant sensors and said signal line for sensing an output signal from a corresponding redundant sensor and for isolating said sensor so that its output signal is not applied to said signal line; and, means for coupling to said signal line a predetermined signal upon the simultaneous or sequential occurrence of sensed output signals from said redundant sensors, said signal line carrying control signals and said sensing and isolating means including means for coupling the control signals carried by said signal line to a corresponding redundant sensor.
Claim 2
Dependent Claim 158 words
Apparatus for a facility monitoring system having a multiwire interconnect cable which includes a signal line, said apparatus permitting the connection of redundant sensors at one location to the multiwire interconnect cable without affecting the operation of non-redundant sensors connected to the interconnect cable, comprising: an adapter module adapted to be coupled between the redundant sensors and the multiwire interconnect cable, said adapter module including means interposed between each of said redundant sensors and said signal line for sensing an output signal from a corresponding redundant sensor and for isolating said sensor so that its output signal is not applied to said signal line; and, means for coupling to said signal line a predetermined signal upon the simultaneous or sequential occurrence of sensed output signals from said redundant sensors, said signal line carrying control signals and said sensing and isolating means including means for coupling the control signals carried by said signal line to a corresponding redundant sensor.
Claim 3
Dependent Claim 29 words
The apparatus of claim 1 wherein system sensors produce a predetermined output signal and wherein said predetermined signal is the same type output signal as generated by system sensors.
Claim 4
Dependent Claim 37 words
The apparatus of claim 1 wherein said system has a number of lines in said interconnect cable and wherein said adapter module includes means for directly connecting all lines but said signal line to said redundant sensors.
Claim 5
Dependent Claim 15 words
The apparatus of claim 1 wherein said output signal is an alarm condition indicating signal.
Claim 6
Dependent Claim 23 words
The apparatus of claim 1 wherein said sensing and isolating means includes a voltage driver and a current sensor coupled to said driver.
Claim 7
Dependent Claim 48 words
The apparatus of claim 5 wherein said current sensor includes a current sense resistor and wherein said voltage driver includes a high gain operational amplifier having its non-inverting input coupled to said signal line and having its output coupled to its inverting input through said current sense resistor.
Claim 8
Dependent Claim 76 words
The apparatus of claim 6 wherein said current sensor includes said current sense resistor coupled between the output of said voltage driver and said corresponding redundant sensor, a second operational amplifier having an inverting input coupled to the end of said resistor which is coupled to said corresponding redundant sensor, and means coupled to the non-inverting input to said second operational amplifier for providing an offset voltage from the output of said first mentioned operational amplifier.
Claim 9
Dependent Claim 28 words
The apparatus of claim 7 wherein said offset voltage providing means includes a voltage dividing circuit interposed between the output of said first mentioned operational amplifier and ground.
Claim 10
Dependent Claim 45 words
The apparatus of claim 1 wherein said means for coupling said predetermined signal to said signal line includes latch circuits, one each coupled to a sensor output signal sensing means and means for generating said predetermined signal responsive to simultaneous outputs from said latch circuits.
Claim 11
Dependent Claim 25 words
The apparatus of claim 9 wherein each latch circuit includes a monostable multivibrator actuated by an output from a corresponding sensor output signal sensing means.
Claim 12
Dependent Claim 21 words
The apparatus of claim 10 wherein each of said monostable multivibrators is set to time out a predetermined time after actuation.

References Cited (Backward Citations)

US3074053A Cited
US3611335A Cited
US3725888A Cited
US3786501A Cited
US3801978A Cited
US4195286A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-05-24 1985-11-23 1986-05-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-05-24 1989-11-23 1990-05-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-05-24 1993-11-23 1994-05-25 $7700.00 Window Closed / Lapsed

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