US4638244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ground connection monitor
Assignee: General Electric Co
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Filing: 1984-10-22
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Granted: 1987-01-20
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Expires: 2004-10-22
Abstract
Abstract A circuit is employed to determine the presence of an open ground connection between a power source and a movable machine connected with the power source by means of a flexible cable. The circuit comprises a pulse generator for transmission of a pulse along the cable between the power source and the movable machine in combination with comparison means for determining whether the reflected pulse back along the cable from the movable machine becomes inverted upon reflection. The presence of a non-inverted reflected pulse indicates an open ground connection. Means are provided for disconnection of power between the power source and the movable machine upon the absence of receipt of an inverted reflected pulse along the connecting cable.
Inventors
- 👤 Edward K. Howell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:05
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08; G01R31/11; G01R27/00; G01R27/02; G01R27/16; G01R27/18; G01R31/50
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
164 words
Apparatus for monitoring the continuity of a pair of conductors in a multiconductor cable comprising: pulse generating means for transmitting a pulse of a first polarity from a first line termination at one end of said conductors along said pair of conductors; means for receiving said pulse upon reflection from a second line termination at an opposite end of said conductors and for comparing the polarity of said received pulse relative to said transmitted pulse; means connected with said comparison means for providing a response in accordance with said comparison; said means connected with said comparison means providing said response when said reflected pulse arrives at said receiving means with a predetermined polarity and at a predetermined time after said transmitted pulse; and said receiving means including an amplifier connected at one of its inputs to said first line termination and at another of its inputs to a DC reference for amplifying said received pulse when said received pulse is of a predetermined polarity.
Claim 2
Dependent Claim
164 words
Apparatus for monitoring the continuity of a pair of conductors in a multiconductor cable comprising: pulse generating means for transmitting a pulse of a first polarity from a first line termination at one end of said conductors along said pair of conductors; means for receiving said pulse upon reflection from a second line termination at an opposite end of said conductors and for comparing the polarity of said received pulse relative to said transmitted pulse; means connected with said comparison means for providing a response in accordance with said comparison; said means connected with said comparison means providing said response when said reflected pulse arrives at said receiving means with a predetermined polarity and at a predetermined time after said transmitted pulse; and said receiving means including an amplifier connected at one of its inputs to said first line termination and at another of its inputs to a DC reference for amplifying said received pulse when said received pulse is of a predetermined polarity.
Claim 3
Dependent Claim
51 words
The apparatus of claim 1 wherein said response means includes an integrator for averaging a plurality of said received pulses and a first comparator connected with said integrator for comparing said average received pulse to a reference and for providing a signal to operate a relay in response to said comparison.
Claim 4
Dependent Claim
44 words
The apparatus of claim 2 further including a second comparator connected with said integrator, and a first, second and third indicator connected with said reference for comparing said average received pulse to a reference voltage and indicating the level of said average received pulse.
Claim 5
Dependent Claim
26 words
The apparatus of claim 2 further including a light source connected with said first comparator to provide an indication of the operation of said third comparator.
Claim 6
Dependent Claim
32 words
The apparatus of claim 8 wherein said second line termination comprises a capacitor connected between said pair of conductors or a direct connection between said pair of conductors at an opposite end.
Claim 7
Dependent Claim
40 words
The apparatus of claim 3 further including a source of DC potential and a filter connected with a third comparator and one of said conductors for comparing the level of a DC voltage along said conductor with a reference voltage.
Claim 8
Dependent Claim
57 words
The apparatus of claim 3 wherein said first indicator is operated when said average received pulse is at a first level of voltage, said second indicator is operated when said average received pulse is at second level of voltage, and said third indicator is operated when said average received pulse is at a third level of voltage.
Claim 9
Dependent Claim
16 words
The apparatus of claim 7 including means for controlling the voltage level of said transmitted pulse.
Claim 10
Dependent Claim
122 words
Apparatus for monitoring the continuity of a pair of conductors in a multiconductor cable comprising: pulse generating means for transmitting a pulse of a first polarity from a first line termination at one end of said conductors along said pair of conductors; means for receiving said pulse upon reflection from a second line termination at an opposite end of said conductors; and means including a gated amplifier connected at one of its inputs to said first line termination, and adjustable time delay means connected with said pulse generator for enabling said gated amplifier to amplify said received pulse only when the time delay between said transmitted and said received pulse corresponds to a propagation time characterized by length of said multiconductor cable.
Claim 11
Dependent Claim
122 words
Apparatus for monitoring the continuity of a pair of conductors in a multiconductor cable comprising: pulse generating means for transmitting a pulse of a first polarity from a first line termination at one end of said conductors along said pair of conductors; means for receiving said pulse upon reflection from a second line termination at an opposite end of said conductors; and means including a gated amplifier connected at one of its inputs to said first line termination, and adjustable time delay means connected with said pulse generator for enabling said gated amplifier to amplify said received pulse only when the time delay between said transmitted and said received pulse corresponds to a propagation time characterized by length of said multiconductor cable.
Claim 12
Dependent Claim
23 words
The apparatus of claim 9 wherein said first line termination comprises an impedance connected between said pair of conductors at said one end.
Claim 13
Dependent Claim
32 words
The apparatus of claim 9 wherein said multiconductor cable includes at least one grounded conductor and at least one power carrying conductor for connection between a power source and a movable machine.
Claim 14
Dependent Claim
29 words
The apparatus of claim 11 wherein said multiconductor cable connecting between said movable machine and said power supply includes three separate phase power conductors and three separate grounding conductors.
Claim 15
Dependent Claim
21 words
The apparatus of claim 12 wherein one of said grounding conductors has a smaller diameter than the other two grounding conductors.
References Cited (Backward Citations)
US3911358A
Cited
US3671856A
Cited
US3710240A
Cited
US3670240A
Cited
US3753086A
Cited
US3909712A
Cited
US3895264A
Cited
US4041381A
Cited
US3934176A
Cited
US4075675A
Cited
US3995200A
Cited
US4104582A
Cited
US4023154A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |