Patent US3985839A successfully refreshed from Google Patents.
Patent US3825776A successfully refreshed from Google Patents.
US3825776A
Expired / Lapsed
US
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Switchable current generator
Assignee: International Business Machines Corp
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Filing: 1972-12-13
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Granted: 1974-07-23
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Expires: 1992-12-13
Abstract
Abstract A current generator comprising switchable circuit means for selectively establishing current loops for providing high stable null, and equal but opposite polarity currents dependent only on resistive means.
Inventors
- 👤 C Jacquart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:05
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/22
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
208 words
A switchable current generator comprising: A. first and second input switching terminals and a pair of first and second circuit means connected to said first and second input switching terminals, B. first and second diode conducting means connected to an output terminal, C. impedance means connected across said first and second diode conducting means for establishing first and second nodes, and said input terminals being selectively responsive to first input signals for selectively activating said first circuit means for generating a current of a first polarity and amplitude through said first diode conducting means, and said input terminals being responsive to second input signals for generating a second current of identical amplitude but opposite polarity with respect to said output terminal through said second diode conducting means, D. said input terminals being responsive to third input signals for providing a null current, E. said first circuit means comprising a first biasing means connected to said first node for rendering said first diode conducting means non-conductive, F. a current sink connected between said first biasing means and a first voltage source for drawing current from said first node, and G. said first circuit means being responsive to a first input signals sink for drawing current from said current sink.
Claim 2
Dependent Claim
208 words
A switchable current generator comprising: A. first and second input switching terminals and a pair of first and second circuit means connected to said first and second input switching terminals, B. first and second diode conducting means connected to an output terminal, C. impedance means connected across said first and second diode conducting means for establishing first and second nodes, and said input terminals being selectively responsive to first input signals for selectively activating said first circuit means for generating a current of a first polarity and amplitude through said first diode conducting means, and said input terminals being responsive to second input signals for generating a second current of identical amplitude but opposite polarity with respect to said output terminal through said second diode conducting means, D. said input terminals being responsive to third input signals for providing a null current, E. said first circuit means comprising a first biasing means connected to said first node for rendering said first diode conducting means non-conductive, F. a current sink connected between said first biasing means and a first voltage source for drawing current from said first node, and G. said first circuit means being responsive to a first input signals sink for drawing current from said current sink.
Claim 3
Dependent Claim
90 words
A switchable current generator as in claim 1 wherein said first biasing means further comprises: A. a third diode conducting means connected between said first reference potential means connected between said first reference potential and a third node common to the said current sink and to said first input switching terminal for passing current from said first reference potential towards said third node, and B. a fourth diode current conducting means connected between said first and third nodes for passing a current from said second node toward said third node.
Claim 4
Dependent Claim
92 words
A switchable current generator as in claim 2 wherein: A. said first circuit means further comprises a first transistor having its collector connected to a second voltage source and a base terminal connected to said first input switching terminal for receiving said first input signals, and B. a fifth diode conducting means connected between said emitter of said first transistor and said third node for passing current from said emitter terminal of said first transistor toward said third node, said first transistor being selectively switched in response to said first input signals.
Claim 5
Dependent Claim
67 words
A current generator as in claim 2 wherein: A. said first circuit means further comprises a sixth diode conducting element connected between said third node and said first input switching terminal for establishing a current flow from said first input switching terminal to said third node in response to said first input signals at said first input switching terminal for selectively switching said sixth diode conducting means.
Claim 6
Dependent Claim
102 words
A switchable current generator as in claim 1 wherein said second circuit means further include: A. second biasing means connected to said second node for selectively switching said second diode conducting means, B. a current source connected between said second biasing means and a second voltage source, said current source supplying a current to said second node, and C. a second input switching terminal connected between said current source and said first voltage source, and a current flow being selectively established between said second node and said second input terminal in response to said second input signals at said second input terminal.
Claim 7
Dependent Claim
78 words
A current generator as in claim 5 wherein said second biasing means includes: A. a seventh diode conducting means connected between a second reference potential and a fourth node common to said current source and to said second input switching terminal for passing current from said fourth node towards said second reference potential, and B. an eighth diode conducting means connected between said second and fourth nodes for passing current from said fourth node to said second node.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |