Patent US3895286A successfully refreshed from Google Patents.
US3895286A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric circuit for providing temperature compensated current
Assignee: RCA Licensing Corp
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Filing: 1971-01-07
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Granted: 1975-07-15
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Expires: 1991-01-07
Abstract
Abstract An electrical circuit including a resistor, a voltage source and a temperature independent voltage divider arrangement, the voltage divider including semiconductor amplifying devices for coupling the source across the resistor and being arranged such that the temperature variation of the resistor value and that of the divided voltage impressed across the resistor are substantially equal to provide a temperature compensated, substantially constant current through the resistor. The desired output current is provided from a relatively high source impedance by means of one of the semiconductor devices of the divider or by means of an additional semiconductor device.
Inventors
- 👤 Steven Alan Steckler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:59
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/18; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/562
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
192 words
An electrical circuit comprising: a first resistance exhibiting a predetermined relative change in resistance value as a function of temperature, a source of operating voltage having supply and reference terminals, coupling means exhibiting, between first and second terminals adapted for connection to said first resistance, a predetermined relative change of voltage as a function of temperature selected with respect to said resistance change, for producing a temperature compensated current through said first resistance, said coupling means comprising: a voltage divider including at least first and second transistors, each having base, emitter and collector electrodes, a second resistance direct current coupled between said supply terminal and said collector of said first transistor, a third resistance proportionally related to said second resistance direct current coupled between said reference terminal and said emitter of said first transistor, means for direct current coupling said base and emitter electrodes of said second transistor, respectively, to said collector and base electrodes of said first transistor, and means comprising at least one semiconductor junction exhibiting a negAtive temperature coefficient of voltage for direct current coupling said first resistance between said emitter of said second transistor and said reference terminal.
Claim 2
Dependent Claim
192 words
An electrical circuit comprising: a first resistance exhibiting a predetermined relative change in resistance value as a function of temperature, a source of operating voltage having supply and reference terminals, coupling means exhibiting, between first and second terminals adapted for connection to said first resistance, a predetermined relative change of voltage as a function of temperature selected with respect to said resistance change, for producing a temperature compensated current through said first resistance, said coupling means comprising: a voltage divider including at least first and second transistors, each having base, emitter and collector electrodes, a second resistance direct current coupled between said supply terminal and said collector of said first transistor, a third resistance proportionally related to said second resistance direct current coupled between said reference terminal and said emitter of said first transistor, means for direct current coupling said base and emitter electrodes of said second transistor, respectively, to said collector and base electrodes of said first transistor, and means comprising at least one semiconductor junction exhibiting a negAtive temperature coefficient of voltage for direct current coupling said first resistance between said emitter of said second transistor and said reference terminal.
Claim 3
Dependent Claim
39 words
An electrical circuit according to claim 1 wherein: said coupling means comprises voltage stabilizing means coupled between said supply and reference terminals for supplying to said voltage divider a voltage substantially unaffected by amplitude variations of said operating voltage.
Claim 4
Dependent Claim
37 words
An electrical circuit according to claim 2 wherein: said second and third resistances are selected to provide a voltage between said first and second terminals such that said relative changes in resistance and voltage are substantially equal.
Claim 5
Dependent Claim
18 words
An electrical circuit according to claim 2 wherein: said first resistance exhibits a positive temperature coefficient of resistance.
Claim 6
Dependent Claim
51 words
An electrical circuit according to claim 2 wherein: said first resistance exhibits a positive temperature coefficient of resistance, said second and third resistances being selected to provide a voltage between said first and second terminals related to the ratio of said temperature coefficient of voltage and said temperature coefficient of resistance.
Claim 7
Dependent Claim
48 words
An electrical circuit according to claim 4 wherein: said semiconductor junction is poled in the same direction as the base-emitter junction of said second transistor and is direct coupled between said second and reference terminals, said emitter of said second transistor being direct coupled to said first terminal.
Claim 8
Dependent Claim
24 words
An electrical circuit according to claim 6 wherein: said voltage stabilizing means comprises an avalanche diode direct coupled between said supply and reference terminals.
Claim 9
Dependent Claim
23 words
An electrical circuit according to claim 7 wherein: said second transistor is arranged for providing said temperature compensated current at its collector electrode.
Claim 10
Dependent Claim
52 words
An electrical circuit according to claim 7 wherein: said means for direct current coupling said first resistance between said second transistor emitter and said reference terminal further comprises a third transistor having base and emitter electrodes directly connected across said semiconductor junction and a collector electrode at which said current is provided.
Claim 11
Dependent Claim
165 words
An electrical circuit comprising: a source of operating voltage having supply and reference terminals, an avalanche diode direct current coupled across said terminals, a first resistance exhibiting a positive temperature coefficient of resistance, a semiconductor diode exhibiting a negative temperature coefficient of voltage direct current coupling one end of said resistance to said reference terminal, a voltage divider coupled between the other end of said resistance and said avalanche diode comprising: at least first and second transistors, each having base, emitter and collector electrodes, a second resistance direct current coupled between said avalanche diode and said collector of said first transistor, a third resistance proportionally related to said second resistance direct current coupled between said reference terminal and said emitter of said first transistor, and means for direct current coupling said base and emitter electrodes of said second transistor, respectively, to said collector and base electrodes of said first transistor and for direct current coupling said emitter of said second transistor to said first resistance.
Claim 12
Dependent Claim
165 words
An electrical circuit comprising: a source of operating voltage having supply and reference terminals, an avalanche diode direct current coupled across said terminals, a first resistance exhibiting a positive temperature coefficient of resistance, a semiconductor diode exhibiting a negative temperature coefficient of voltage direct current coupling one end of said resistance to said reference terminal, a voltage divider coupled between the other end of said resistance and said avalanche diode comprising: at least first and second transistors, each having base, emitter and collector electrodes, a second resistance direct current coupled between said avalanche diode and said collector of said first transistor, a third resistance proportionally related to said second resistance direct current coupled between said reference terminal and said emitter of said first transistor, and means for direct current coupling said base and emitter electrodes of said second transistor, respectively, to said collector and base electrodes of said first transistor and for direct current coupling said emitter of said second transistor to said first resistance.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |