US3838248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature control device for thermostatic oven
Assignee: NEC Corp
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Filing: 1973-09-06
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Granted: 1974-09-24
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Expires: 1993-09-06
Abstract
Abstract A temperature control device for a thermostatic oven or the like is provided with an input temperature-sensitive, resistive bridge network. Any imbalance voltage in the bride network is integrated by an electronic integrator to provide an output intergrated voltage. The output integrated voltage is amplified by a power amplifier which supplies the heater element in the oven. The effect of the arrangement is such as to minimize the offset voltage in the feedback loop with the result that changes in the ambient temperature and power supply voltage have less effect on the operation of the device.
Inventors
- 👤 H Uchida
- 👤 T Hamatsuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:09
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
128 words
A temperature control device for a thermostatic oven including a vacuum bottle having a metallic case therein, an element to be temperature-controlled by said device, said element being included in said metallic case, heating means attached to said metallic case for heating said metallic case, temperaturesensing means attached to said metallic case for sensing the temperature of said metallic case, comprising: means for converting the deviation of the temperature of said metallic case from a predetermined temperature to a temperature-control signal, said converting means including said temperature-sensing means; means coupled to said converting means for integrating said temperature-control signal; and means responsive to the output of said integrating means for applying heating power to said heating means, thereby to keep the temperature of said thermostatic oven substantially constant.
Claim 2
Dependent Claim
128 words
A temperature control device for a thermostatic oven including a vacuum bottle having a metallic case therein, an element to be temperature-controlled by said device, said element being included in said metallic case, heating means attached to said metallic case for heating said metallic case, temperaturesensing means attached to said metallic case for sensing the temperature of said metallic case, comprising: means for converting the deviation of the temperature of said metallic case from a predetermined temperature to a temperature-control signal, said converting means including said temperature-sensing means; means coupled to said converting means for integrating said temperature-control signal; and means responsive to the output of said integrating means for applying heating power to said heating means, thereby to keep the temperature of said thermostatic oven substantially constant.
Claim 3
Dependent Claim
30 words
A temperature control device as recited in claim 1 wherein said means for converting is a resistive bridge and said temperature-sensing means comprises at least one arm of the bridge.
Claim 4
Dependent Claim
76 words
A temperature control device as recited in claim 2 wherein said means for integrating comprises operational amplifier means; a capacitor connected between the input and output of said operational amplifier means; and a resistor connected between the output of said resistive bridge and the input of said operational amplifier means, whereby the integral time of said means for integrating is determined by the product of the resistance of said resistor and the capacitance of said capacitor.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |