Patent US3634875A successfully refreshed from Google Patents.
US3634875A
Expired / Lapsed
US
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Bidirectional direct-current detector with transformer isolation
Assignee: Westinghouse Electric Corp
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Filing: 1970-06-24
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Granted: 1972-01-11
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Expires: 1990-06-24
Abstract
Abstract A DC-detector wherein the DC to be detected is utilized to modify the amplitude and mark-space timing of an oscillator utilizing a common magnetic circuit and wherein the so-modified output is integrated and differentially amplified to provide a bidirectional output indicative of the amplitude and direction of the DC being detected.
Inventors
- 👤 Bryan J Bixby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:40
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/08; H02H3/081; G; G01; G01R; G01R19/00; G01R19/14; G01R19/18; G01R19/20; H02H3/087
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
163 words
In a system for detecting the magnitude and direction of a direct current, the combination of: a transformer including a magnetic core comprising a saturable material and primary and secondary windings; means for applying said direct current to be detected to selected of said secondary windings; an oscillator circuit coupled via said primary windings for oscillation with a substantially equal mark and space durations in the absence of said direct current to be detected and with unequal durations in the presence of said direct current to be detected; means responsive to said mark-and-space durations for providing a signal having a predetermined value when said durations are substantially equal and differing from said predetermined value in magnitude and direction in accordance with the magnitude and direction of inequality between said mark-and-space durations respectively; and means for comparing said signal with a reference signal and providing a comparison output in response thereto indicative of the magnitude and direction of said direct current to be detected.
Claim 2
Dependent Claim
163 words
In a system for detecting the magnitude and direction of a direct current, the combination of: a transformer including a magnetic core comprising a saturable material and primary and secondary windings; means for applying said direct current to be detected to selected of said secondary windings; an oscillator circuit coupled via said primary windings for oscillation with a substantially equal mark and space durations in the absence of said direct current to be detected and with unequal durations in the presence of said direct current to be detected; means responsive to said mark-and-space durations for providing a signal having a predetermined value when said durations are substantially equal and differing from said predetermined value in magnitude and direction in accordance with the magnitude and direction of inequality between said mark-and-space durations respectively; and means for comparing said signal with a reference signal and providing a comparison output in response thereto indicative of the magnitude and direction of said direct current to be detected.
Claim 3
Dependent Claim
58 words
The combination of claim 1 wherein: said means responsive to said mark-and-space durations includes another of said secondary windings responsive to said durations, integrating means for integrating the input thereto, and means for coupling said another winding to provide the input to said integrator means so that said integrator means provides said signal to said means for comparing.
Claim 4
Dependent Claim
52 words
The combination of claim 2 wherein: said another winding provides outputs of opposite polarity respectively in response to said mark-and-space durations of said oscillator, and said means for coupling comprises a switching device operative to be rendered conductive or nonconductive in response to the opposite polarity outputs respectively of said another winding.
Claim 5
Dependent Claim
37 words
The combination of claim 1 wherein: said means for comparing comprises differential amplifier means for receiving said signal as one input and said reference signal as another input and providing said comparison output as the difference therebetween.
Claim 6
Dependent Claim
37 words
The combination of claim 3 wherein: said means for coupling comprises differential amplifier means for receiving said signal as one input and said reference signal as another input and providing said comparison output as the difference therebetween.
Claim 7
Dependent Claim
42 words
The combination of claim 1 wherein: said direct current to be detected comprises the algebraic sum of a first component and a second component, said first and second components are applied to first and second windings of said selected secondary windings, respectively.
Claim 8
Dependent Claim
37 words
THe combination of claim 6 wherein: the turns-ratio between said first and second windings is selected so that substantially equal mark-and-space durations are provided when said second and first components bear the same ratio as said turns-ratio.
Claim 9
Dependent Claim
40 words
The combination of claim 7 wherein: said first component and said second component are respectively supplied by first and second DC supplies, and said comparison output is indicative of the degree of unbalance between said first and second DC sources.
Claim 10
Dependent Claim
67 words
The combination of claim 1 wherein: said transformer includes a feedback winding, and the combination includes means for applying a feedback direct signal to said feedback winding in response to said comparison output, said selected and said feedback windings are so wound that the magnetic flux produced in said coil in response to said direct current to be detected and said feedback direct current substantially balance out.
Claim 11
Dependent Claim
28 words
The combination of claim 9 includes means for measuring said feedback direct current as an indication of the direction and magnitude of said direct current to be detected.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |