Patent US4424491A successfully refreshed from Google Patents.
US4424491A
Expired / Lapsed
US
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Automatic voltage imbalance detector
Assignee: United States Department of Energy
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Filing: 1981-05-20
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Granted: 1984-01-03
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Expires: 2001-05-20
Abstract
Abstract A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.
Inventors
- 👤 Ronald E. Bobbett
- 👤 J. Byron McCormick
- 👤 William J. Kerwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:29
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/04; H01M8/04298; H01M8/04313; H01M8/04664; H01M8/04671; B; B60; B60L; B60L3/00; B60L3/0023; B60L58/00; B60L58/30; B60L58/32; B60L58/33; B60L58/34; G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542; G01R31/00; G01R31/36; G01R31/396; H01M10/00; H01M10/42; H01M10/44; H01M10/441; H01M10/48; H01M10/482; H01M8/04537; H01M8/04544; H01M8/04552; H01M8/04694; H01M8/04858; H01M8/04865; H01M8/24; H01M8/249; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02E60/30; Y02E60/50; Y02T; Y02T90/00; Y02T90/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
147 words
A device for indicating malfunction of at least one voltage cell in a plurality of voltage cells connected in series comprising: means for adding the voltage magnitudes of two adjacent voltage cells of said plurality of voltage cells connected in series at upper and lower voltage points to obtain a sum voltage; means for comparing said sum voltage with a central voltage between said two adjacent voltage cells to obtain an error voltage proportional to the difference between said sum voltage and said central voltage; and switching means for providing an output whenever said error voltage exceeds a predetermined magnitude indicative of a malfunction of at least one of said voltage cells, said switching means having a first transistor connected to conduct whenever said error signal exceeds a predetermined positive voltage and a second transistor connected to conduct whenever said error signal exceeds a predetermined negative voltage.
Claim 2
Independent Claim
147 words
A device for indicating malfunction of at least one voltage cell in a plurality of voltage cells connected in series comprising: means for adding the voltage magnitudes of two adjacent voltage cells of said plurality of voltage cells connected in series at upper and lower voltage points to obtain a sum voltage; means for comparing said sum voltage with a central voltage between said two adjacent voltage cells to obtain an error voltage proportional to the difference between said sum voltage and said central voltage; and switching means for providing an output whenever said error voltage exceeds a predetermined magnitude indicative of a malfunction of at least one of said voltage cells, said switching means having a first transistor connected to conduct whenever said error signal exceeds a predetermined positive voltage and a second transistor connected to conduct whenever said error signal exceeds a predetermined negative voltage.
Claim 3
Dependent Claim
143 words
An automatic voltage imbalance detector comprising: a plurality of voltage cells connected in series such that each two adjacent voltage cells have lower, middle and upper voltage points at connection points in said series; means for combining the voltage magnitudes at said upper and lower voltage points to obtain a sum voltage; operational amplifier means for comparing said sum voltage with the voltage magnitude at said middle voltage point to produce an error signal proportional to the difference between said sum voltage and the voltage magnitude at said middle voltage point; and switching means for producing an output signal whenever said comparison signal exceeds a predetermined error voltage, said switching means having a first transistor connected to conduct whenever said error signal exceeds a predetermined positive voltage and a second transistor connected to conduct whenever said error signal exceeds a predetermined negative voltage.
Claim 4
Dependent Claim
143 words
An automatic voltage imbalance detector comprising: a plurality of voltage cells connected in series such that each two adjacent voltage cells have lower, middle and upper voltage points at connection points in said series; means for combining the voltage magnitudes at said upper and lower voltage points to obtain a sum voltage; operational amplifier means for comparing said sum voltage with the voltage magnitude at said middle voltage point to produce an error signal proportional to the difference between said sum voltage and the voltage magnitude at said middle voltage point; and switching means for producing an output signal whenever said comparison signal exceeds a predetermined error voltage, said switching means having a first transistor connected to conduct whenever said error signal exceeds a predetermined positive voltage and a second transistor connected to conduct whenever said error signal exceeds a predetermined negative voltage.
Claim 5
Independent Claim
134 words
A device for preventing damage to series connected voltage cells due to excessive discharge comprising: means for detecting voltage levels between said series connected voltage cells during discharge; means for comparing adjacent voltage levels to produce difference voltage signals; means for comparing adjacent difference voltage signals to produce an error voltage signal proportional to the difference between said difference voltage signals; and switching means for producing an output voltage switching signal whenever said error voltage signal exceeds a predetermined absolute magnitude indicative of potential damage to said voltage cells, said switching means having a first transistor connected to produce an output switching signal whenever said error voltage signal exceeds a predetermined positive voltage and a second transistor connected to produce an output switching signal whenever said error voltage signal exceeds a predetermined negative voltage.
Claim 6
Independent Claim
134 words
A device for preventing damage to series connected voltage cells due to excessive discharge comprising: means for detecting voltage levels between said series connected voltage cells during discharge; means for comparing adjacent voltage levels to produce difference voltage signals; means for comparing adjacent difference voltage signals to produce an error voltage signal proportional to the difference between said difference voltage signals; and switching means for producing an output voltage switching signal whenever said error voltage signal exceeds a predetermined absolute magnitude indicative of potential damage to said voltage cells, said switching means having a first transistor connected to produce an output switching signal whenever said error voltage signal exceeds a predetermined positive voltage and a second transistor connected to produce an output switching signal whenever said error voltage signal exceeds a predetermined negative voltage.
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) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |