US3950273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Medium temperature thermistor
Assignee: International Standard Electric Corp
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Filing: 1973-07-05
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Granted: 1976-04-13
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Expires: 1993-07-05
Abstract
Abstract A thermistor material of between 99% and 50% by weight of praseodymium oxide and 1 to 50% by weight of zirconium oxide provides a stable thermistor with desired resistance value changes over a temperature range of 100°C to 600°C. Other selected oxides may be used in place of zirconium. Small amounts of indium or gallium oxides can also be added to the mixture to lower the resistivity and temperature coefficient of resistance.
Inventors
- 👤 Colin Stanley Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:12
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/04; H01C7/042; H01C7/043
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
41 words
A thermistor comprising a mixture of between 99% and 50% by weight of Pr 6 O 11 and 1% to 50% by weight of an oxide of the group of metals consisting of thorium, aluminum, hafnium, zinc, cadmium, mercury and magnesium.
Claim 2
Dependent Claim
41 words
A thermistor comprising a mixture of between 99% and 50% by weight of Pr 6 O 11 and 1% to 50% by weight of an oxide of the group of metals consisting of thorium, aluminum, hafnium, zinc, cadmium, mercury and magnesium.
Claim 3
Dependent Claim
21 words
The thermistor of claim 1, wherein said Pr 6 O 11 is from 75 to 99% by weight of said mixture.
Claim 4
Dependent Claim
11 words
The thermistor of claim 2, wherein said oxide is zinc oxide.
Claim 5
Dependent Claim
11 words
The thermistor of claim 2, wherein said oxide is thorium oxide.
Claim 6
Dependent Claim
24 words
The thermistor of claim 2, wherein said oxide is aluminum oxide of up to 10% by weight and including a further oxide of zirconium.
Claim 7
Dependent Claim
17 words
The thermistor of claim 4, including a further oxide of aluminum of up to 10% by weight.
Claim 8
Dependent Claim
49 words
A thermistor comprising a mixture of between 75% and 99% by weight of Pr 6 O 11 and 25% to 1% by weight of zirconium oxide and further including from 0 to 4% by weight of a material selected from the group consisting of indium oxide and gallium oxide.
Claim 9
Dependent Claim
49 words
A thermistor comprising a mixture of between 75% and 99% by weight of Pr 6 O 11 and 25% to 1% by weight of zirconium oxide and further including from 0 to 4% by weight of a material selected from the group consisting of indium oxide and gallium oxide.
Claim 10
Dependent Claim
24 words
The thermistor of claim 7, wherein said mixture has a negative temperature coefficient of resistance operable in the range of from 100°C to 600°C.
References Cited (Backward Citations)
US3235655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |