US3728616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuity testing apparatus utilizing a plurality of paired resistors
Assignee: AT&T Inc
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Filing: 1971-02-02
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Granted: 1973-04-17
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Expires: 1991-02-02
Abstract
Abstract An apparatus tests for wiring errors in connections between a plurality of pairs of terminals. The apparatus includes a plurality of pairs of matched resistors with one pair of terminals connected between each respective pair of resistors across a voltage source. The voltage across one of each pair of resistors is sensed to determine a voltage above or below a predetermined range of voltages to indicate a defectively wired circuit. Each pair of resistors has matched resistors with values differing sufficiently from every other pair of resistors to operate the voltage sensing facilities in the event there are crossed or erroneous connections.
Inventors
- 👤 H Cheek
- 👤 H May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:05
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/50; G01R31/66; G01R31/67
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
175 words
An apparatus for detecting an erroneous condition in a first connection between first and second terminals and in a second connection between third and fourth terminals, comprising: means for supplying a predetermined voltage: first, second, third and fourth resistances, said first and second resistances having relative values with a predetermined ratio, said third and fourth resistances having relative values with said predetermined ratio, said first and third resistances having respective values which differ by at least a predetermined percent; means for connecting the first and second resistances in series with the first and second terminals across the voltage supplying means and for connecting the third and fourth resistances in series with the third and fourth terminals across the voltage supplying means, said first and second terminals being interposed between said first and second resistances and said third and fourth terminals being interposed between said third and fourth resistances; and means sensing the voltage across one of the first and second resistances and across one of the third and fourth resistances for detecting the erroneous condition.
Claim 2
Independent Claim
175 words
An apparatus for detecting an erroneous condition in a first connection between first and second terminals and in a second connection between third and fourth terminals, comprising: means for supplying a predetermined voltage: first, second, third and fourth resistances, said first and second resistances having relative values with a predetermined ratio, said third and fourth resistances having relative values with said predetermined ratio, said first and third resistances having respective values which differ by at least a predetermined percent; means for connecting the first and second resistances in series with the first and second terminals across the voltage supplying means and for connecting the third and fourth resistances in series with the third and fourth terminals across the voltage supplying means, said first and second terminals being interposed between said first and second resistances and said third and fourth terminals being interposed between said third and fourth resistances; and means sensing the voltage across one of the first and second resistances and across one of the third and fourth resistances for detecting the erroneous condition.
Claim 3
Independent Claim
152 words
An apparatus for testing for errors in a plurality of connections between a corresponding plurality of pairs of terminals, comprising: means for supplying a predetermined voltage; means for electrically contacting the plurality of pairs of terminals; a plurality of pairs of resistances corresponding to the plurality of connections to be tested, each pair of resistances connected in series with a corresponding pair of terminals across said voltage supplying means such that each pair of terminals is interposed between first and second resistances of each corresponding pair of resistances; the first and second resistances of each pair of resistances having values with the same predetermined ratio; the first resistance of each pair of resistances having a value which differs from the value of every other first resistance by more than a predetermined percent; and means sensing voltages across one of said first and second resistances of each pair of resistances for detecting errors.
Claim 4
Independent Claim
152 words
An apparatus for testing for errors in a plurality of connections between a corresponding plurality of pairs of terminals, comprising: means for supplying a predetermined voltage; means for electrically contacting the plurality of pairs of terminals; a plurality of pairs of resistances corresponding to the plurality of connections to be tested, each pair of resistances connected in series with a corresponding pair of terminals across said voltage supplying means such that each pair of terminals is interposed between first and second resistances of each corresponding pair of resistances; the first and second resistances of each pair of resistances having values with the same predetermined ratio; the first resistance of each pair of resistances having a value which differs from the value of every other first resistance by more than a predetermined percent; and means sensing voltages across one of said first and second resistances of each pair of resistances for detecting errors.
Claim 5
Dependent Claim
49 words
An apparatus as defined in claim 2 wherein the detecting means includes: first means operated by a voltage above a predetermined range of voltages for indicating a first error condition; and second means operated by a voltage below the predetermined range of voltages for indicating a second error condition.
Claim 6
Dependent Claim
73 words
An apparatus as defined in claim 2 wherein the detecting means includes: a plurality of first means connected across respective ones of said first and second resistances and operated by voltages above a predetermined range of voltages for indicating first error conditions; and a plurality of second means connected across respective ones of said first and second resistances and operated by voltages below a predetermined range of voltages for indicating second error conditions.
Claim 7
Dependent Claim
67 words
An apparatus as defined in claim 4 wherein: each of the first means includes a first indicating device and first gating means operated by voltages above the predetermined range of voltages for actuating the first indicating device; and each of the second means includes a second indicating device and second gating means operated by voltages below the predetermined range of voltages for actuating the second indicating device.
Claim 8
Dependent Claim
33 words
Apparatus as defined in claim 2 wherein the first resistance of each pair of resistances has a value which differs from the value of every other first resistance by more than 18 percent.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |