US3695112A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrically operated temperature sensing assembly
Assignee: Individual
•
Filing: 1970-10-14
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Granted: 1972-10-03
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Expires: 1990-10-14
Abstract
Abstract A temperature sensing assembly that indicates the temperature of an electrical resistance element containing sensor by comparing the differential in voltages between that in a first feedback loop and the voltage in a second feedback loop of which said sensor forms a part. The operating components of the assembly are: the temperature sensor; an electric power supply; a voltmeter; and an electric circuit that includes first and second operational amplifiers that have said first and second loops associated therewith and means in said circuit for supplying a constant current input to said amplifiers. The sensor may be any resistance element that has a variable linear resistance value over a substantial temperature range. However, the assembly is considered to operate with optimum results, when the sensor described in the specification is used therewith.
Inventors
- 👤 Clarence R Possell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:29
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/16; G01K7/18; G01K7/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
234 words
A temperature sensing assembly that includes: a. electrical resistance temperature sensing means that varies linearly in resistance in relation to the temperature to which said sensing means is exposed; b. metering means that is responsive to variations in voltage; c. a reference operational amplifier and a measuring operational amplifier; d. a reference feedback loop and a measuring feedback loop connected to the output and the input of said reference amplifier and said measuring amplifier, said measuring loop including said sensing means; e. electric circuit means connected to a source of power and to said reference and measuring amplifiers; f. first means in said circuit for supplying constant current to the inputs of said references and measuring amplifiers; g. second means in said circuit that connect said metering means to said reference and measuring feedback loops; and h. third variable resistance means in said circuit for maintaining said metering means at a zero position when said reference and measuring loops are at the same temperature, but upon said sensing means being exposed to a temperature different from that of said reference loop the resistance of said measuring loop changing and varying the output of said measuring amplifier and the magnitude of the voltage in said measuring loop, and said metering means indicating the voltage differential between said reference and measuring loops that is linearly related to the temperature to which said sensing means is exposed.
Claim 2
Dependent Claim
234 words
A temperature sensing assembly that includes: a. electrical resistance temperature sensing means that varies linearly in resistance in relation to the temperature to which said sensing means is exposed; b. metering means that is responsive to variations in voltage; c. a reference operational amplifier and a measuring operational amplifier; d. a reference feedback loop and a measuring feedback loop connected to the output and the input of said reference amplifier and said measuring amplifier, said measuring loop including said sensing means; e. electric circuit means connected to a source of power and to said reference and measuring amplifiers; f. first means in said circuit for supplying constant current to the inputs of said references and measuring amplifiers; g. second means in said circuit that connect said metering means to said reference and measuring feedback loops; and h. third variable resistance means in said circuit for maintaining said metering means at a zero position when said reference and measuring loops are at the same temperature, but upon said sensing means being exposed to a temperature different from that of said reference loop the resistance of said measuring loop changing and varying the output of said measuring amplifier and the magnitude of the voltage in said measuring loop, and said metering means indicating the voltage differential between said reference and measuring loops that is linearly related to the temperature to which said sensing means is exposed.
Claim 3
Dependent Claim
17 words
A temperature sensing assembly as defined in claim 1 in which said metering means is a voltmeter.
Claim 4
Dependent Claim
19 words
A tEmperature sensing assembly as defined in claim 2 in which said voltmeter is calibrated to read temperatures directly.
Claim 5
Dependent Claim
27 words
A temperature sensing assembly as defined in claim 1 in which said first means includes a transistor, a plurality of resistors and a plurality of Zener diodes.
Claim 6
Dependent Claim
33 words
A temperature sensing assembly as defined in claim 1 in which said third means is a potentiometer and at least one resistor shunt connected to the outputs of said reference and measuring amplifiers.
References Cited (Backward Citations)
US3429178A
Cited
US3379973A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |