Patent US3912883A successfully refreshed from Google Patents.
US3912883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current supervisory system
Assignee: SPX Technologies Inc
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Filing: 1974-03-26
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Granted: 1975-10-14
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Expires: 1994-03-26
Abstract
Abstract A supervisory system for a plurality of line wire pairs which line wire pairs may be used for distribution of audio or digital information. DC energy, for supervisory purposes, is supplied to each of the line wire pairs which are separately and continuously monitored for faults. The continuous monitoring of the line wire pairs takes place even after detection of a fault so that, when the fault is repaired, the equipment automatically responds to the repair. The faults that can be detected include short and open circuits. Detection of an open circuit is signaled but information is allowed to flow down the opened line pair as far as possible. Detection of a short circuit results in removing the information transmission to protect information flow on other line wire pairs. A resistor across each line wire pair at the detection point ensures a minimum flow of direct current so that polarized capacitors can be used rather than less desirable bipolar capacitors.
Inventors
- 👤 Walter David Goodyear
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:51
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/46
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
137 words
A supervisory system for supervising, at a central location, an information transmission system with at least one pair of line wires, said information transmission system including information source connected to said one pair of line wires, said supervisory system comprising, means supplying direct current energy to said pair of line wires, first resistive means connected across said pair of line wires remote from said central location, second resistive means connected across said pair of line wires at said central location, detector means at said central location responsive to the direct current on one of said pair of line wires and, control means connected to said detector means operating in response to said detector means detecting a distinctive trouble condition on said pair of line wires for disconnecting said pair of line wires from said information transmission source.
Claim 2
Dependent Claim
137 words
A supervisory system for supervising, at a central location, an information transmission system with at least one pair of line wires, said information transmission system including information source connected to said one pair of line wires, said supervisory system comprising, means supplying direct current energy to said pair of line wires, first resistive means connected across said pair of line wires remote from said central location, second resistive means connected across said pair of line wires at said central location, detector means at said central location responsive to the direct current on one of said pair of line wires and, control means connected to said detector means operating in response to said detector means detecting a distinctive trouble condition on said pair of line wires for disconnecting said pair of line wires from said information transmission source.
Claim 3
Dependent Claim
110 words
The apparatus of claim 1 in which said information transmission system comprises a plurality of pairs of line wires, each connected to said information source, with first and second resistive means in which further includes a plurality of detector means, one for each pair of line wires, each of said detector means responsive to direct current on the associated pair of line wires and a plurality of control means, each associated with a different one of said detector means for disconnecting the associated pair of line wires from said information source in response to the assoociated detector means detecting a distinctive trouble condition on the associated pair of line wires.
Claim 4
Dependent Claim
58 words
The apparatus of claim 1 in which said information transmission system includes a transformer, one winding of said transformer coupled to said pair of line wires and which include in said supervisory system, switches responsive to said control means to open a connection between said pair of line wires and said winding when said control means is operated.
Claim 5
Dependent Claim
71 words
The apparatus of claim 2 in which said information transmission system includes a transformer, one winding of said transformer coupled to all said pairs of line wires and which include, in said supervisory system, switches associated with each of said control means, responsive to operation of the associated control means, to open a connection between one of said pairs of line wires and said winding when said control means is operated.
Claim 6
Dependent Claim
31 words
The apparatus of claim 1 which further includes indicator means responsive to said detector means for indicating one of the plurality of distinctive trouble conditions on said pair of line wires.
Claim 7
Dependent Claim
35 words
The apparatus of claim 2 which includes a plurality of indicator means each associated with a different detector means for indicating one of a plurality of trouble conditions on an associated pair of line wires.
Claim 8
Dependent Claim
82 words
The apparatus of claim 1 in which said detector means comprises, a voltage divider connected acrosS said means for supplying direct current energy with at least two taps to provide a pair of reference voltages, a sensing circuit to provide a direct current sensed voltage proportional to said direct current flowing in one of said pair of line wires, and a pair of comparator means each distinctively responsive to the relative magnitude of one of said reference voltages and said sensed voltage.
Claim 9
Dependent Claim
15 words
The apparatus of claim 1 in which each of said resistive means includes a resistor.
Claim 10
Dependent Claim
138 words
A supervisory system for supervising, at a central location, an information transmission system with at least one pair of line wires comprising, means for supplying direct current supervision energy to said pair of line wires including a pair of terminals, capacitive means coupled across said means supplying direct current, detector means at said central location responsive to the direct current on one of said pair of line wires, and connected between one of said pair of line wires and one of said two terminals of said means for supplying direct current, resistive means connected across said pair of line wires remote from said central location, second capacitive means connected across said detector means, second resistive means connected across said pair of line wires at said central location, and both said first and second capacitive means including polarized capacators.
Claim 11
Dependent Claim
138 words
A supervisory system for supervising, at a central location, an information transmission system with at least one pair of line wires comprising, means for supplying direct current supervision energy to said pair of line wires including a pair of terminals, capacitive means coupled across said means supplying direct current, detector means at said central location responsive to the direct current on one of said pair of line wires, and connected between one of said pair of line wires and one of said two terminals of said means for supplying direct current, resistive means connected across said pair of line wires remote from said central location, second capacitive means connected across said detector means, second resistive means connected across said pair of line wires at said central location, and both said first and second capacitive means including polarized capacators.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |