US3842674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Remote air temperature indicator
Assignee: Beecham Group PLC
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Filing: 1972-05-01
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Granted: 1974-10-22
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Expires: 1992-05-01
Abstract
Abstract A remote air temperature indicator is provided wherein a thermister is used as a temperature sensing element followed by a stable linear amplifier whereby a linear readout is provided on an analog-type meter. Preferably the thermistor is a composite thermistor network having a wide range of linearity from low to high temperatures.
Inventors
- 👤 R Wilbur
- 👤 A Stickney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:29
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/16; G01K7/22; G01K7/24; G01K7/25
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
339 words
A remote temperature indicator comprising in combination: a. a temperature sensing network connected with a supply voltage and including a thermistor element mounted at a remote point on a ship or the like and a zero adjust means connected between said network and actual ground wherein said adjust means is adjusted to set the output voltage of said network to equal a reference signal ground voltage when said thermistor element is at -40*F (-40*C), b. a first operational amplifier connected as an inverting amplifier wherein said output voltage of said network is connected to the negative inverting input and said reference voltage is connected to the positive non-inverting input of said amplifier whereby said output voltage is inverted and amplified, c. a meter connected to the output of said first operational amplifier whereby the meter reading is directly proportional to said output voltage of said network, d. a calibration means for said meter connected in series between said output of said first operational amplifier and said meter whereby said calibration means is adjusted to insure that said meter reads 120*F (55*C) when said thermistor is at said temperature, e. a reference voltage generator comprising a voltage divider connected between said supply voltage and said actual ground to produce a signal ground voltage therebetween, said voltage connected to the positive non-inverting input of a second operational amplifier operating as a non-inverting voltage follower whereby the output of said second amplifier is said reference signal ground voltage, f. a first capacitor connected between said output voltage of said network and said reference signal ground voltage, g. a second capacitor connected between said reference signal ground voltage and said actual ground, and h. a third capacitor connected to said output voltage of said network and in parallel with said thermistor element whereby, i. any strong electrical interference to said output voltage of said network and to said thermistor element will be effectively bypassed to said actual ground, permitting said indicator to function in the immediate vicinity of a high power radio transmitter.
Claim 2
Dependent Claim
339 words
A remote temperature indicator comprising in combination: a. a temperature sensing network connected with a supply voltage and including a thermistor element mounted at a remote point on a ship or the like and a zero adjust means connected between said network and actual ground wherein said adjust means is adjusted to set the output voltage of said network to equal a reference signal ground voltage when said thermistor element is at -40*F (-40*C), b. a first operational amplifier connected as an inverting amplifier wherein said output voltage of said network is connected to the negative inverting input and said reference voltage is connected to the positive non-inverting input of said amplifier whereby said output voltage is inverted and amplified, c. a meter connected to the output of said first operational amplifier whereby the meter reading is directly proportional to said output voltage of said network, d. a calibration means for said meter connected in series between said output of said first operational amplifier and said meter whereby said calibration means is adjusted to insure that said meter reads 120*F (55*C) when said thermistor is at said temperature, e. a reference voltage generator comprising a voltage divider connected between said supply voltage and said actual ground to produce a signal ground voltage therebetween, said voltage connected to the positive non-inverting input of a second operational amplifier operating as a non-inverting voltage follower whereby the output of said second amplifier is said reference signal ground voltage, f. a first capacitor connected between said output voltage of said network and said reference signal ground voltage, g. a second capacitor connected between said reference signal ground voltage and said actual ground, and h. a third capacitor connected to said output voltage of said network and in parallel with said thermistor element whereby, i. any strong electrical interference to said output voltage of said network and to said thermistor element will be effectively bypassed to said actual ground, permitting said indicator to function in the immediate vicinity of a high power radio transmitter.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |