Patent US1499887A successfully refreshed from Google Patents.
US3700934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature-compensated current reference
Assignee: Veolia WTS Systems USA Inc
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Filing: 1971-09-23
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Granted: 1972-10-24
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Expires: 1991-09-23
Abstract
Abstract Electrical circuits are described that can be connected in series with a voltage source and a load in the same manner as a field-effect current-regulator diode to supply the load with a constant current having a temperature coefficient below 0.01%/*C. from 0* to 60* C. at current levels as low as 10 microamperes and having a voltage coefficient below 0.1%/volt from 5 to 12 volts. Very precise temperature compensation can be achieved at the desired current by adjustment of two resistors in these circuits.
Inventors
- 👤 Charles Gardner Swain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:35
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/24; G05F3/242; G05F3/245
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
An electrical circuit to regulate direct current with temperature compensation, comprising a field-effect transistor (FET), a second semiconductor and two resistors, the source lead of the said FET connected to one side of each of said resistors, said second semiconductor connected between the opposite sides of said resistors, the FET gate connected to one side of said second semiconductor, the other side of said second semiconductor connected to one end of the series combination of the voltage source and the load to be regulated, and the FET drain connected to the other end of said series combination of the said voltage source and the said load.
Claim 2
Dependent Claim
106 words
An electrical circuit to regulate direct current with temperature compensation, comprising a field-effect transistor (FET), a second semiconductor and two resistors, the source lead of the said FET connected to one side of each of said resistors, said second semiconductor connected between the opposite sides of said resistors, the FET gate connected to one side of said second semiconductor, the other side of said second semiconductor connected to one end of the series combination of the voltage source and the load to be regulated, and the FET drain connected to the other end of said series combination of the said voltage source and the said load.
Claim 3
Dependent Claim
75 words
An electrical circuit in accordance with claim 1 wherein said second semiconductor is a diode, the said FET is an N-channel field-effect transistor, the said FET gate connected to the anode side of said diode with the cathode side of said diode connected to the negative end of said series combination of voltage source and load, and the said FET drain connected to the positive end of said series combination of voltage source and load.
Claim 4
Dependent Claim
75 words
An electrical circuit in accordance with claim 1 wherein said second semiconductor is a diode, the said FET is a P-channel field-effect transistor, the said FET gate connected to the cathode side of said diode with the anode side of said diode connected to the positive end of said series combination of voltage source and load, and the said FET drain connected to the negative end of said series combination of voltage source and load.
Claim 5
Dependent Claim
15 words
An electrical circuit in accordance with claim 1 wherein said second semiconductor is a thermistor.
Claim 6
Dependent Claim
19 words
An electrical circuit in accordance with claim 1 wherein said second semiconductor is a transistor, appropriately biased by resistors.
Claim 7
Dependent Claim
103 words
An electrical circuit to regulate direct current with temperature compensation, comprising a field-effect transistor (FET), a second semiconductor and two resistors, the first of said resistors shunted by a series combination of said second semiconductor and the second of said resistor, the FET gate connected to one side of said first resistor and to one end of the series combination of voltage source and load to be regulated, the FET source lead connected to the other side of said first resistor, and the FET drain connected to the other end of said series combination of the said voltage source and the said load.
Claim 8
Dependent Claim
103 words
An electrical circuit to regulate direct current with temperature compensation, comprising a field-effect transistor (FET), a second semiconductor and two resistors, the first of said resistors shunted by a series combination of said second semiconductor and the second of said resistor, the FET gate connected to one side of said first resistor and to one end of the series combination of voltage source and load to be regulated, the FET source lead connected to the other side of said first resistor, and the FET drain connected to the other end of said series combination of the said voltage source and the said load.
Claim 9
Dependent Claim
93 words
An electrical circuit in accordance with claim 6 wherein said second semiconductor is a diode, the FET is an N-channel field-effect transistor, the FET gate connected to the cathode end of said series combination of said diode and said second resistor and to the negative end of said series combination of voltage source and load, the FET source lead connected to the anode end of said series combination of said diode and said second resistor, and the FET drain connected to the positive end of said series combination of voltage source and load.
Claim 10
Dependent Claim
93 words
An electrical circuit in accordance with claim 6 wherein said second semiconductor is a diode, the FET is a P-channel field-effect transistor, the FET gate connected to the anode end of said series combination of said diode and said second resistor and to the positive end of said series combination of voltage source and load, the FET source lead connected to the cathode end of said series combination of said diode and said second resistor, and the FET drain connected to the negative end of said series combination of voltage source and load.
Claim 11
Dependent Claim
15 words
An electrical circuit in accordance with claim 6 wherein said second semiconductor is a thermistor.
Claim 12
Dependent Claim
19 words
An electrical circuit in accordance with claim 6 wherein said second semiconductor is a transistor, appropriately biased by resistors.
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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |