US4812752A
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Assignee: Honeywell International Inc
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Filing: 1987-10-19
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Granted: 1989-03-14
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Expires: 2007-10-19
Abstract
Abstract A circuit tester provides an indication of open circuit faults of individual conductors in cables. An oscillator circuit in the tesster includes a capacitance as an internal part of the circuit. Test probes connect conductor pairs to the oscillator circuit, thus changing the effective capacitance of the circuit. This changes the frequency output of the oscillator in accordance with the length of the conductors. Test indications may include a low pass filter and an audio circuit, or a circuit to convert frequency to a voltage or digitalized output. The tester may be used with automated test equipment.
Inventors
- 👤 Ernest A. Preuss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:46
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2605; G01R31/00; G01R31/50; G01R31/52; G01R31/54; G01R31/58; G01R31/66; G01R31/68; G01R31/69
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
144 words
Apparatus for detecting and locating open circuit faults in a cable bundle having a plurality of conductors and a first and second end, comprising: (a) an oscillator having a frequency of oscillation at an output and two output terminals, one to be connected to one of said conductors and the other to be connected to a second of said conductors so as to modify said frequency of oscillation according to the capacitance between said two input terminals so that said oscillator will have a modified frequency of oscillation at said output, (b) a filter having an output and an input connected to said output of said oscillator, said filter alternating said frequency of oscillation, and (c) means for indicating the frequency at said output of said filter, which means for indicating can be interpreted to detect and locate open circuit faults in the cable.
Claim 2
Dependent Claim
144 words
Apparatus for detecting and locating open circuit faults in a cable bundle having a plurality of conductors and a first and second end, comprising: (a) an oscillator having a frequency of oscillation at an output and two output terminals, one to be connected to one of said conductors and the other to be connected to a second of said conductors so as to modify said frequency of oscillation according to the capacitance between said two input terminals so that said oscillator will have a modified frequency of oscillation at said output, (b) a filter having an output and an input connected to said output of said oscillator, said filter alternating said frequency of oscillation, and (c) means for indicating the frequency at said output of said filter, which means for indicating can be interpreted to detect and locate open circuit faults in the cable.
Claim 3
Dependent Claim
22 words
The apparatus as in claim 1, wherein said filter outputs said modified frequency of oscillation when said two input terminals are connected.
Claim 4
Dependent Claim
14 words
The apparatus as in claim 1, wherein said filter is a low pass filter.
Claim 5
Dependent Claim
15 words
The apparatus as in claim 1, wherein said filter amplifies said modified frequency of oscillation.
Claim 6
Dependent Claim
14 words
The apparatus as in claim 1, wherein said means for indicating is a speaker.
Claim 7
Dependent Claim
27 words
The apparatus as in claim 5, wherein said speaker generates a sound having a tone which is related to the frequency at said output of said filter.
Claim 8
Dependent Claim
42 words
The apparatus as in claim 5, wherein said speaker generates a sound when said two input terminals of aid oscillator are connected to said cable bundle, said sound having a tone which is related to the capacitance between said two input terminals.
Claim 9
Dependent Claim
20 words
The apparatus as in claim 1, wherein said means for indicating comprises a frequency to voltage converter and a voltmeter.
Claim 10
Dependent Claim
24 words
The apparatus as in claim 8, wherein said voltmeter indicates a voltage which is related to the frequency at said output of said filter.
Claim 11
Dependent Claim
39 words
The apparatus as in claim 8, wherein said voltmeter indicates no voltage when said two input terminals are unconnected and indicates a voltage related to the capacitance between said two input terminals when said two input terminals are connected.
Claim 12
Dependent Claim
20 words
The apparatus as in claim 1, wherein said means for indicating is activated when said two input terminals are connected.
Claim 13
Independent Claim
156 words
A method for testing a cable bundle comprising a plurality of conductors to locate an open circuit in a first conductor in said cable bundle by using a tester having two input terminals and a filtered output dependent on the capacitance between said input terminals, said open circuit having been detected by checking said plurality of conductors for continuity, said method comprising the steps of: (a) connecting each of said input terminals to a second and a third conductor within said cable bundle at a first end of said cable bundle, (b) noting said output of said tester, (c) connecting one of said input terminals to said first conductor at said first end of said cable bundle, (d) noting said output of said tester, and (e) locating said open circuit in said first conductor at said first end of said cable bundle if said output from step (d) is notably different from said output step (b).
Claim 14
Independent Claim
156 words
A method for testing a cable bundle comprising a plurality of conductors to locate an open circuit in a first conductor in said cable bundle by using a tester having two input terminals and a filtered output dependent on the capacitance between said input terminals, said open circuit having been detected by checking said plurality of conductors for continuity, said method comprising the steps of: (a) connecting each of said input terminals to a second and a third conductor within said cable bundle at a first end of said cable bundle, (b) noting said output of said tester, (c) connecting one of said input terminals to said first conductor at said first end of said cable bundle, (d) noting said output of said tester, and (e) locating said open circuit in said first conductor at said first end of said cable bundle if said output from step (d) is notably different from said output step (b).
Claim 15
Dependent Claim
103 words
A method as in claim 12, further comprising the steps of: (f) connecting each of said input terminals to a second and a third conductor within said cable bundle at a second end of said cable bundle, (g) noting said output of said tester, (h) connecting one of said input terminals to said first conductor at said second end of said cable bundle, (i) noting said output of said tester, and (j) locating said open circuit in said first conductor at said second end of said cable bundle if said output from step (i) is notably different from said output from step (g).
Claim 16
Dependent Claim
15 words
A method as in claim 12, wherein said output of said tester is a frequency.
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) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |