US3629692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current source with positive feedback current repeater
Assignee: RCA Corp
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Filing: 1971-01-11
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Granted: 1971-12-21
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Expires: 1991-01-11
Abstract
Abstract A two-terminal current-limiting or current source arrangement is coupled across a source of voltage which is subject to variations. The limiter includes a current determining resistor connected in the base-emitter circuit of a first transistor. A second transistor provides negative feedback between collector and base of the first transistor and also provides a collectoremitter circuit in series with the resistor. A current repeater is connected between the collectors of the first and second transistors and produces positive feedback to the base of the second transistor. The repeater includes a transistor, the collector-emitter circuit of which is connected to the collector of the first transistor. The voltage source is of sufficient magnitude to bias the repeater transistor and second transistor to nonsaturated conduction.
Inventors
- 👤 Ronald Bruce Goyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:46
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/26; G05F3/265
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
107 words
A current-limiting circuit comprising a first semiconductor device having base, emitter and collector electrodes, a resistor coupled between said base and emitter electrodes, means including a second semiconductor device having a collector-emitter circuit coupled to said resistor for supplying current to said resistor and having a base-emitter circuit coupled between said collector and base electrodes of said first device, means, including third and fourth semiconductor devices having proportionally related conduction characteristics, for providing positive feedback between said collector and base electrodes of said second device, and means coupled between said emitter of said first device and said positive feedback means for supplying energized potential to said devices.
Claim 2
Dependent Claim
107 words
A current-limiting circuit comprising a first semiconductor device having base, emitter and collector electrodes, a resistor coupled between said base and emitter electrodes, means including a second semiconductor device having a collector-emitter circuit coupled to said resistor for supplying current to said resistor and having a base-emitter circuit coupled between said collector and base electrodes of said first device, means, including third and fourth semiconductor devices having proportionally related conduction characteristics, for providing positive feedback between said collector and base electrodes of said second device, and means coupled between said emitter of said first device and said positive feedback means for supplying energized potential to said devices.
Claim 3
Dependent Claim
41 words
A current-limiting circuit according to claim 1 wherein said third and fourth devices comprise input circuits coupled in parallel, and said third and fourth devices further comprise output circuits coupled respectively, to the collector-emitter circuits of said second and first devices.
Claim 4
Dependent Claim
35 words
A current-limiting circuit according to claim 2 wherein each of said semiconductor devices comprises a transistor having base, emitter and collector electrodes, the base and collector electrodes of said third transistor being directly connected together.
Claim 5
Dependent Claim
25 words
A current-limiting arrangement according to claim 3 wherein said energizing potential is of sufficient magnitude to bias said second and fourth transistors to nonsaturated condition.
Claim 6
Dependent Claim
31 words
A current-limiting circuit according to claim 4 wherein said first and second transiStors are of a first conductivity type and said third and fourth transistors are of a second conductivity type.
Claim 7
Dependent Claim
44 words
A current-limiting circuit according to claim 5 wherein said third and fourth transistors have substantially identical conduction characteristics, and said resistor is selected with a value equal to twice the base-emitter offset voltage of said first transistor divided by a predetermined limit current value.
Claim 8
Dependent Claim
170 words
An electrical circuit for providing a predetermined current comprising a first transistor having base, emitter and collector electrodes, a resistor connected between said base and emitter electrodes, a second transistor having base, emitter and collector electrodes, said emitter of said second transistor being connected to said base of said first transistor, said base of said second transistor being coupled to said collector of said first transistor, a diode-connected transistor and a fourth transistor, each having base, emitter and collector electrodes, and exhibiting proportionally related conduction characteristics, the collector electrode of said diode-connected transistor being connected to the collector of said second transistor and to the base electrodes of said diode-connected and fourth transistors, the collector electrode of said fourth transistor being connected to the collector electrode of said first transistor, and a source of voltage coupled from said emitter electrodes of said diode-connected and fourth transistors to the emitter electrode of said first transistor, said voltage being of sufficient amplitude to maintain said second and fourth transistors in nonsaturated conjunction.
Claim 9
Dependent Claim
170 words
An electrical circuit for providing a predetermined current comprising a first transistor having base, emitter and collector electrodes, a resistor connected between said base and emitter electrodes, a second transistor having base, emitter and collector electrodes, said emitter of said second transistor being connected to said base of said first transistor, said base of said second transistor being coupled to said collector of said first transistor, a diode-connected transistor and a fourth transistor, each having base, emitter and collector electrodes, and exhibiting proportionally related conduction characteristics, the collector electrode of said diode-connected transistor being connected to the collector of said second transistor and to the base electrodes of said diode-connected and fourth transistors, the collector electrode of said fourth transistor being connected to the collector electrode of said first transistor, and a source of voltage coupled from said emitter electrodes of said diode-connected and fourth transistors to the emitter electrode of said first transistor, said voltage being of sufficient amplitude to maintain said second and fourth transistors in nonsaturated conjunction.
Claim 10
Dependent Claim
31 words
An electrical circuit according to claim 7 wherein said first and second transistors are of a first conductivity type, and said diode-connected and fourth transistors are of a second conductivity type.
Claim 11
Dependent Claim
37 words
An electrical circuit according to claim 8 wherein the magnitude of said voltage is greater than the sum of the collector to emitter voltage of said first transistor plus the base-emitter offset voltage of said diode-connected transistor.
Claim 12
Dependent Claim
40 words
An electrical circuit according to claim 9 wherein said diode-connected and fourth transistors exhibit substantially identical conduction characteristics, and said resistor is selected equal to twice the base-emitter offset voltage of said first transistor divided by a predetermined limit current.
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) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |