Patent US3559883A successfully refreshed from Google Patents.
US3559883A
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Temperature control
Assignee: Texas Instruments Inc
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Filing: 1969-03-03
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Granted: 1971-02-02
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Expires: 1989-03-03
Abstract
Abstract The apparatus disclosed herein proportionally controls a gasburning heating system to maintain a zone to which heat is supplied at a predetermined temperature level. The flow of gas is varied by a valve the setting of which is adjusted by means of an electrically energized, thermal expansion actuator. A thermistor is provided for sensing the temperature in the controlled zone and the actuator is energized according to a predetermined function of the resistance of the thermistor thereby to maintain the temperature in the zone at the predetermined level.
Inventors
- 👤 Francis P Buiting
- 👤 Joseph W Waseleski Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:59
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906; G05D23/1909; G05D23/1919; G05D23/1921
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
76 words
A temperature control comprising: means for providing heat flow relative to a zone at a rate which is variable over a continuous range; an electrical load; means responsive to the energization of said load for varying said rate; an electrothermal oscillator for variably energizing said load; and a sensing thermistor responsive to the temperature in said zone for varying the operation of said oscillator thereby to maintain the temperature in said zone at a predetermined level.
Claim 2
Dependent Claim
76 words
A temperature control comprising: means for providing heat flow relative to a zone at a rate which is variable over a continuous range; an electrical load; means responsive to the energization of said load for varying said rate; an electrothermal oscillator for variably energizing said load; and a sensing thermistor responsive to the temperature in said zone for varying the operation of said oscillator thereby to maintain the temperature in said zone at a predetermined level.
Claim 3
Dependent Claim
27 words
A temperature control as set forth in claim 1 wherein said oscillator comprises first and second thermistor elements having positive and negative temperature coefficients of resistance respectively.
Claim 4
Dependent Claim
34 words
A temperature control as set forth in claim 2 wherein said sensing thermistor, said first and second thermistor elements, and said load are connected in series across a source providing a substantially constant voltage.
Claim 5
Dependent Claim
23 words
A temperature control as set forth in claim 3 wherein said electrical load comprises a heater in an electrically energized thermal expansion actuator.
Claim 6
Dependent Claim
28 words
A temperature contrOl as set forth in claim 2 wherein each of said first and second thermistor elements has a current-voltage characteristic which includes a negative resistance region.
Claim 7
Dependent Claim
21 words
A temperature control as set forth in claim 1 in which said sensing thermistor has a positive temperature coefficient of resistance.
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) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |