Patent US4427935A successfully refreshed from Google Patents.
US4427935A
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Constant current source
Assignee: Mobil Oil AS
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Filing: 1981-10-13
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Granted: 1984-01-24
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Expires: 2001-10-13
Abstract
Abstract A constant current source employs a correction signal which is multiplied with the output of the current source to correct for amplitude variations and thereby maintain a constant current output level.
Inventors
- 👤 Edgar A. Bowden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:28
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/565
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
127 words
A system for correcting for amplitude variation in current flow from an unstable oscillatory current source, comprising: (a) a resistive element through which the current from said oscillatory current source is passed, (b) means for producing a reference voltage representative of the voltage differential across said resistive element, (c) a source of fixed D.C. voltage, (d) means for integrating the difference between said reference voltage and said fixed D.C. voltage to produce a correction signal representative of an amplitude variation in said current, (e) means for multiplying the current with said correction signal to correct for said amplitude variation in said oscillatory current source, whereby the current through said resistive element is maintained at a constant level regardless of amplitude instability of the said oscillatory current source.
Claim 2
Independent Claim
127 words
A system for correcting for amplitude variation in current flow from an unstable oscillatory current source, comprising: (a) a resistive element through which the current from said oscillatory current source is passed, (b) means for producing a reference voltage representative of the voltage differential across said resistive element, (c) a source of fixed D.C. voltage, (d) means for integrating the difference between said reference voltage and said fixed D.C. voltage to produce a correction signal representative of an amplitude variation in said current, (e) means for multiplying the current with said correction signal to correct for said amplitude variation in said oscillatory current source, whereby the current through said resistive element is maintained at a constant level regardless of amplitude instability of the said oscillatory current source.
Claim 3
Dependent Claim
44 words
The system of claim 1 wherein said means for producing said reference voltage includes, (a) means for measuring the voltage differential across said resistive element, and (b) means for rectifying said measured voltage differential to remove any DC ripple in said measured voltage differential.
Claim 4
Independent Claim
111 words
A method for controlling amplitude instability in an oscillatory current source, comprising the steps of (a) applying an oscillatory current source to a resistive element, (b) producing a reference voltage representative of the amplitude of the oscillatory current through said resistive element, (c) rectifying said reference voltage, (d) comparing said rectified reference voltage with a fixed voltage, the difference between said reference and fixed voltages being integrated to represent any change in the amplitude of said current due to current source amplitude instability, and (d) multiplying said integrated difference between said fixed and reference voltages with the current from said oscillatory current source to correct said current for oscillatory amplitude instability.
Claim 5
Independent Claim
111 words
A method for controlling amplitude instability in an oscillatory current source, comprising the steps of (a) applying an oscillatory current source to a resistive element, (b) producing a reference voltage representative of the amplitude of the oscillatory current through said resistive element, (c) rectifying said reference voltage, (d) comparing said rectified reference voltage with a fixed voltage, the difference between said reference and fixed voltages being integrated to represent any change in the amplitude of said current due to current source amplitude instability, and (d) multiplying said integrated difference between said fixed and reference voltages with the current from said oscillatory current source to correct said current for oscillatory amplitude instability.
References Cited (Backward Citations)
US3370222A
Cited
US4348632A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |