US3881066A
Expired / Lapsed
US
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DC Signaling method for solid-state crosspoint networks
Assignee: AG Communication Systems Corp
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Filing: 1974-01-02
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Granted: 1975-04-29
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Expires: 1994-01-02
Abstract
Abstract Method and apparatus including a novel DC-coupled junctor circuit for signaling across a solid-state crosspoint matrix network. The junctor comprises a pair of serially connected diodes interposed between the crosspoint network paths. A constant current source (or sink) is coupled to the junction of the diodes to provide a common DC current path therethrough for current coupled through the junctor diodes and the corresponding crosspoint paths and controlled variable impedance networks coupled thereto. Signaling across the solid-state crosspoint network is accomplished by selectively varying the impedance of one of the controlled variable impedance networks responsive to certain conditions being monitored in the interface circuitry associated with the crosspoint path by a corresponding loop supervision circuit. The resultant imbalance in current through the junctor diodes causes corresponding variations in the DC potential at the other crosspoint path output terminal which are monitored to control the interface circuitry coupled thereto. In an embodiment of the invention, the novel junctor circuit is employed in an electronic private automatic branch telephone exchange (EPABX).
Inventors
- 👤 Max S Macrander
- 👤 Ronald F Kowalik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:21
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04Q3/52; H04Q3/521
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
96 words
Apparatus for signaling across a solid-state crosspoint matrix network including first and second crosspoint paths comprising: a source of DC potential; controlled variable impedance means comprising first and second variable impedance networks respectively coupling said first and second crosspoint paths to said DC potential source; and DC-coupled junctor means intercoupling said first and second crosspoint paths, said DC-coupled junctor means varying the respective levels of DC potential developed at the corresponding junctions of said variable impedance networks and said crosspoint paths responsive to controlled variations in the ratio of the impedances of said variable impedance networks.
Claim 2
Dependent Claim
96 words
Apparatus for signaling across a solid-state crosspoint matrix network including first and second crosspoint paths comprising: a source of DC potential; controlled variable impedance means comprising first and second variable impedance networks respectively coupling said first and second crosspoint paths to said DC potential source; and DC-coupled junctor means intercoupling said first and second crosspoint paths, said DC-coupled junctor means varying the respective levels of DC potential developed at the corresponding junctions of said variable impedance networks and said crosspoint paths responsive to controlled variations in the ratio of the impedances of said variable impedance networks.
Claim 3
Dependent Claim
138 words
Apparatus for signaling across a solid-state crosspoint matrix network including first and second crosspoint paths comprising: a source of DC potential; controlled variable impedance means comprising first and second variable impedance networks respectively coupling said first and second crosspoint paths to said DC potential source; and junctor means comprising a pair of DC-coupled diodes D.C. intercoupling said first and second crosspoint paths and a constant current means coupled to the junction of said diodes for maintaining the sum of the DC currents conducted through said diodes at a constant level, controlled variations in the ratio of the impedances of said variable impedance networks resulting in an imbalance in the DC current distribution through said diodes and corresponding variations in the respective levels of DC potential developed at the junctions of said variable impedance networks and said crosspoint paths.
Claim 4
Dependent Claim
138 words
Apparatus for signaling across a solid-state crosspoint matrix network including first and second crosspoint paths comprising: a source of DC potential; controlled variable impedance means comprising first and second variable impedance networks respectively coupling said first and second crosspoint paths to said DC potential source; and junctor means comprising a pair of DC-coupled diodes D.C. intercoupling said first and second crosspoint paths and a constant current means coupled to the junction of said diodes for maintaining the sum of the DC currents conducted through said diodes at a constant level, controlled variations in the ratio of the impedances of said variable impedance networks resulting in an imbalance in the DC current distribution through said diodes and corresponding variations in the respective levels of DC potential developed at the junctions of said variable impedance networks and said crosspoint paths.
Claim 5
Dependent Claim
84 words
Apparatus in accordance with claim 2 including a plane of reference potential wherein said diodes each have respective anode and cathode electrodes, said cathodes being DC-coupled at a common junction and said anodes being D.C. coupled to corresponding ones of said crosspoint paths, and wherein said constant current means comprises a constant current sink coupled between said junction of said diode cathodes and said plane of reference potential, and including second and third constant current sinks coupled at respective ones of said diode anodes.
Claim 6
Dependent Claim
35 words
Apparatus in accordance with claim 2 including level detection means for monitoring the variations in the respective levels of DC potential developed at the corresponding junctions of said variable impedance networks and said crosspoint paths.
Claim 7
Dependent Claim
54 words
Apparatus in accordance with claim 2 wherein each of said variable impedance networks includes a resistive element and switch means for selectively switching said resistive element in and out of said variable impEdance network to vary the impedance thereof and wherein said variable impedance network further includes control means for controlling said switch means.
Claim 8
Dependent Claim
84 words
Apparatus in accordance with claim 5 wherein said resistive element comprises a first resistor and each of said variable impedance networks includes a second resistor coupled in series with said first resistor between said DC potential source and the corresponding one of said crosspoint paths and wherein said switch means is coupled in shunt with said first resistor to selectively shunt said first resistor with a low impedance and thereby vary the ratio of the impedances of said first and second variable impedance networks.
Claim 9
Dependent Claim
64 words
Apparatus in accordance with claim 6 wherein said switch means comprises a transistor having a collector-emitter output circuit and a base electrode, said collector-emitter output circuit being coupled across said first resistor and said base electrode being coupled to said control means, said control means selectively biasing said transistor to conduction to provide a low impedance current path in shunt with said first resistor.
Claim 10
Dependent Claim
86 words
Apparatus in accordance with claim 5 wherein said resistive element comprises a first resistor and each of said variable impedance networks includes a second resistor coupled in shunt with the series combination of said switch means and said first resistor between said DC potential source and the corresponding one of said crosspoint paths, said switch means being selectively switched to conduction to shunt said second resistor with said first resistor and thereby vary the ratio of the impedances of said first and second variable impedance networks.
Claim 11
Dependent Claim
72 words
Apparatus in accordance with claim 8 wherein said switch means comprises a transistor having a collector-emitter output circuit and a base electrode, said collector-emitter output circuit being coupled in series with said first resistor to shunt said second resistor and said base electrode being coupled to said control means, said control means selectively biasing said transistor to conduction to complete the connection of said first resistor in shunt with said second resistor.
Claim 12
Dependent Claim
114 words
In an electronic private automatic branch telephone exchange (EPABX) having a solid-state crosspoint matrix network including a plurality of crosspoint paths for interconnecting telephones, apparatus comprising: a source of DC potential; controlled variable impedance means comprising a plurality of variable impedance networks respectively coupling said crosspoint paths to said DC potential source; and DC-coupled junctor means intercoupling first and second ones of said crosspoint paths, said DC-coupled junctor means varying the respective levels of DC potential developed at the junctions of said first and second crosspoint paths and the corresponding ones of said variable impedance networks responsive to controlled variations in the ratio of the impedances of said first and second variable impedance networks.
Claim 13
Dependent Claim
114 words
In an electronic private automatic branch telephone exchange (EPABX) having a solid-state crosspoint matrix network including a plurality of crosspoint paths for interconnecting telephones, apparatus comprising: a source of DC potential; controlled variable impedance means comprising a plurality of variable impedance networks respectively coupling said crosspoint paths to said DC potential source; and DC-coupled junctor means intercoupling first and second ones of said crosspoint paths, said DC-coupled junctor means varying the respective levels of DC potential developed at the junctions of said first and second crosspoint paths and the corresponding ones of said variable impedance networks responsive to controlled variations in the ratio of the impedances of said first and second variable impedance networks.
Claim 14
Dependent Claim
100 words
Apparatus in accordance with claim 10 wherein said DC-coupled junctor means comprises a pair of DC-coupled diodes intercoupling said first and second crosspoint paths and a constant current means coupled to the junction of said diodes for maintaining the sum of the DC currents conducted through said diodes at a constant level, controlled variations in the ratio of the impedances of said variable impedance networks resulting in an imbalance in the DC current distribution through said diodes and corresponding variations in the respective levels of DC potential developed at the junctions of said variable impedance networks and said crosspoint paths.
Claim 15
Dependent Claim
83 words
Apparatus in accordance with claim 11 including a plane of reference potential wherein said diodes each have respective anode and cathode electrodes, said cathodes being DC-coupled at a common junction and said anodes being coupled to corresponding ones of said crosspoint paths, and wherein said constant current means comprisEs a constant current sink coupled between said junction of said diode cathodes and said plane of reference potential, and including second and third constant current sinks coupled at respective ones of said diode anodes.
Claim 16
Dependent Claim
93 words
Apparatus in accordance with claim 12 wherein said DC-coupled junctor means further includes a constant current sink coupled to the junction of each of said diodes anode and said crosspoint path for signaling from said DC-coupled junctor means across said crosspoint paths, said DC-coupled junctor means further including means for selectively enabling said additional constant current sink to effect an imbalance in the current distribution through said junctor diodes to cause variations in the respective levels of the DC potential developed at the junctions of said crosspoint paths and said variable impedance networks.
Claim 17
Dependent Claim
115 words
Apparatus in accordance with claim 10 including means comprising a plurality of interface circuits for coupling said telephones to corresponding ones of said crosspoint paths, each of said interface circuits comprising a transformer having primary and secondary windings, said telephone being coupled across said primary winding and said secondary winding being interposed between a particular one of said crosspoint paths and the corresponding one of said variable impedance networks, said DC-coupled junctor means varying the respective levels of DC potential developed at the junctions of said crosspoint paths and the corresponding ones of said transformer secondary windings responsive to controlled variations in the ratio of the impedances of said first and second variable impedance networks.
Claim 18
Dependent Claim
36 words
Apparatus in accordance with claim 14 including level detection means for monitoring the variations in the respective levels of DC potential developed at the corresponding junctions of said transformer secondary windings and said variable impedance network.
Claim 19
Dependent Claim
72 words
Apparatus in accordance with claim 14 wherein each of said variable impedance networks includes a resistive element and switch means for selectively switching said resistive element in and out of said variable impedance network to vary the impedance thereof and wherein said variable impedance network further includes loop supervision means for monitoring the corresponding one of said interface circuits and controlling said switch means responsive to current levels in said interface circuit.
Claim 20
Dependent Claim
84 words
Apparatus in accordance with claim 16 wherein said resistive element comprises a first resistor and each of said variable impedance networks includes a second resistor coupled in series with said first resistor between said DC potential source and the corresponding one of said crosspoint paths and wherein said switch means is coupled in shunt with said first resistor to selectively shunt said first resistor with a low impedance and thereby vary the ratio of the impedances of said first and second variable impedance networks.
Claim 21
Dependent Claim
66 words
Apparatus in accordance with claim 17 wherein said switch means comprises a transistor having a collector-emitter output circuit and a base electrode, said collector-emitter output circuit being coupled across said first resistor and said base electrode being coupled to said loop supervision means, said loop supervision means selectively biasing said transistor to conduction to provide a low impedance current path in shunt with said first resistor.
Claim 22
Dependent Claim
86 words
Apparatus in accordance with claim 16 wherein said resistive element comprises a first resistor and each of said variable impedance networks includes a second resistor coupled in shunt with the series combination of said switch means and said first resistor between said DC potential source and the corresponding one of said crosspoint paths, said switch means being selectively switched to conduction to shunt said second resistor with said first resistor and thereby vary the ratio of the impedances of said first and second variable impedance networks.
Claim 23
Dependent Claim
74 words
Apparatus in accordance with claiM 19 wherein said switch means comprises a transistor having a collector-emitter output circuit and a base electrode, said collector-emitter output circuit being coupled in series with said first resistor to shunt said second resistor and said base electrode being coupled to said loop supervision means, said loop supervision means selectively biasing said transistor to conduction to complete the connection of said first resistor in shunt with said second resistor.
Claim 24
Independent Claim
163 words
The method of signaling across a solid-state crosspoint matrix network in a EPABX system having interface circuitry for coupling telephones to said EPABX, said crosspoint network including a plurality of crosspoint paths for interconnecting said telephones, said EPABX system also including a plurality of variable impedance networks for coupling corresponding ones of said crosspoint paths to a source of DC potential, and a DC-coupled junctor for intercoupling a particular pair of said crosspoint paths, said method comprising: monitoring said interface circuitry; varying the impedance of said variable impedance networks responsive to current levels being monitored in said interface circuitry, said DC-coupled junctor varying the respective levels of DC ppotential developed at the corresponding junctions of said variable impedance networks and said corresponding crosspoint paths responsive to variations in the ratio of the impedances of said variable impedance networks; and detecting said DC potential variations to control a second of said interface circuits responsive to conditions monitored in the first of said interface circuits.
Claim 25
Independent Claim
163 words
The method of signaling across a solid-state crosspoint matrix network in a EPABX system having interface circuitry for coupling telephones to said EPABX, said crosspoint network including a plurality of crosspoint paths for interconnecting said telephones, said EPABX system also including a plurality of variable impedance networks for coupling corresponding ones of said crosspoint paths to a source of DC potential, and a DC-coupled junctor for intercoupling a particular pair of said crosspoint paths, said method comprising: monitoring said interface circuitry; varying the impedance of said variable impedance networks responsive to current levels being monitored in said interface circuitry, said DC-coupled junctor varying the respective levels of DC ppotential developed at the corresponding junctions of said variable impedance networks and said corresponding crosspoint paths responsive to variations in the ratio of the impedances of said variable impedance networks; and detecting said DC potential variations to control a second of said interface circuits responsive to conditions monitored in the first of said interface circuits.
References Cited (Backward Citations)
US3666892A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |