US3728620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission line fault indicator and locator utilizing variable frequency source coupled to one end of line
Assignee: Individual
•
Filing: 1971-07-14
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Granted: 1973-04-17
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Expires: 1991-07-14
Abstract
Abstract A system is disclosed which locates open and short-circuit faults on a transmission line by sensing a minimum occuring at the input end of the line. The apparatus comprises a variable frequency test signal source coupled to the input of an amplifier the output of which is adapted for connection to the input end of the transmission line. The frequency of the test signal is varied until a minimum is sensed at the output of the amplifier indicating the presence of a fault on the line. The location of the fault, that is, the distance from the input end of the line to the fault, is determined by the frequency of the source signal at which the minimum is produced. Means are provided in the system for resolving the ambiguity between an open-circuit fault and a short-circuit fault.
Inventors
- 👤 J Heins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:30
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08; G01R31/081; G01R31/085
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
A device for locating a fault condition on a transmission line or the like comprising an amplifier having an output adapted for connection to one end of a transmission line under test, a variable frequency signal source coupled to the input of said amplifier, the transmission line when a fault is present thereon constituting a resonant circuit coupled to the output of said amplifier, means operatively connected to said signal source for varying the frequency of said signal, means operatively connected to the output of said amplifier for sensing at said one end a minimum signal in response to the occurrence of resonance of said resonant circuit at the frequency of said test signal, and means coupled to and responsive to said frequency-varying means for indicating the location of the fault with respect to the distance of the fault from said one end of the line corresponding to the frequency of said signal source at which said minimum signal is obtained.
Claim 2
Independent Claim
161 words
A device for locating a fault condition on a transmission line or the like comprising an amplifier having an output adapted for connection to one end of a transmission line under test, a variable frequency signal source coupled to the input of said amplifier, the transmission line when a fault is present thereon constituting a resonant circuit coupled to the output of said amplifier, means operatively connected to said signal source for varying the frequency of said signal, means operatively connected to the output of said amplifier for sensing at said one end a minimum signal in response to the occurrence of resonance of said resonant circuit at the frequency of said test signal, and means coupled to and responsive to said frequency-varying means for indicating the location of the fault with respect to the distance of the fault from said one end of the line corresponding to the frequency of said signal source at which said minimum signal is obtained.
Claim 3
Dependent Claim
50 words
The system of claim 1, in which said sening means comprises means for detecting an effective null resulting from the presence of either an operative short-circuit or an operative open circuit fault on the line, and further comprising means for determining which of said faults is present on the line.
Claim 4
Dependent Claim
39 words
The system of claim 2, in which said determining means comprises means for selectively applying a d.c. signal to said line, and means for measuring the current flow through the line upon the application of said d.c. signal thereto.
Claim 5
Dependent Claim
45 words
The system of claim 3, in which said null detecting means defines said current-measuring means, said d.c. signal-applying means comprising switch means effective when said d.c. signal is applied to said line to disconnect said null indicating means from operative connection with said signal source.
Claim 6
Dependent Claim
31 words
The system of claim 4, further comprising line select means operatively connected to said indicating means for varying the latter in accord with the transmissive nature of the line under test.
Claim 7
Dependent Claim
31 words
The system of claim 1, further comprising line select means operatively connected to said indicating means for varying the latter in accord with the transmissive nature of the line under test.
Claim 8
Dependent Claim
31 words
The system of claim 2, further comprising line select means operatively connected to said indicating means for varying the latter in accord with the transmissive nature of the line under test.
References Cited (Backward Citations)
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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) | 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 |