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Patent US3737622A successfully refreshed from Google Patents.
US3737622A
Expired / Lapsed
US
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Temperature-regulating apparatus
Assignee: Danfoss AS
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Filing: 1971-06-02
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Granted: 1973-06-05
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Expires: 1991-06-02
Abstract
Abstract Electrical heating apparatus having temperature controllable regulating means. The apparatus includes, in series, heating and PTC resistors and a temperature responsive switch. An electric motor driven variable speed blower is arranged to blow cooling air over the heating and PTC resistors. A temperature sensor and bridge apparatus cooperates to produce a voltage signal which is proportional to the deviation of the temperature from a predetermined temperature. Upon a drop in temperature the proportional voltage signal is produced and, upon being amplified, the series switch is closed to admit current to the resistors and the blower motor is driven at a speed proportional to the voltage signal. The degree or extent to which the PTC resistor is cooled by the blower determines the resistance it presents in the circuit such that increased cooling of the PTC resistors results in a greater heat output by the heating resistor, and vice versa.
Inventors
- 👤 K Hallgreen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:48
CPC Classifications
F; F24; F24H; F24H9/00; F24H9/18; F24H9/1854; F24H9/1863; F24H9/1872; F24H3/00; F24H3/02; F24H3/04; F24H3/0405; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1919; G05D23/20; G05D23/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
Heating apparatus comprising a circuit having a heating resistor, a PTC resistor in series with said heating resistor, terminal means for said circuit for connection to a power supply, ambient temperature sensing means, controllable and regulatable air supply means and including regulating means responsive to said temperature sensing means for directing a regulated stream of cooling air over said PTC resistor to increase or decrease the flow of current through said heating resistor in direct proportion with the deviation from a desired temperature as sensed by the sensing means, said air supply means comprising a variable speed blower and said regulating means regulating the speed of said blower.
Claim 2
Dependent Claim
108 words
Heating apparatus comprising a circuit having a heating resistor, a PTC resistor in series with said heating resistor, terminal means for said circuit for connection to a power supply, ambient temperature sensing means, controllable and regulatable air supply means and including regulating means responsive to said temperature sensing means for directing a regulated stream of cooling air over said PTC resistor to increase or decrease the flow of current through said heating resistor in direct proportion with the deviation from a desired temperature as sensed by the sensing means, said air supply means comprising a variable speed blower and said regulating means regulating the speed of said blower.
Claim 3
Dependent Claim
37 words
Heating apparatus according to claim 1 wherein said blower has an AC motor, said regulating means includes phase chopping control means for regulating the speed of said motor in accordance with the temperature sensed by the sensor.
Claim 4
Dependent Claim
29 words
Heating apparatus according to claim 1 wherein said blower produces an air stream for cooling both of said resistors, said heating resistor being positioned downstream from said PTC resistor.
Claim 5
Dependent Claim
71 words
Heating apparatus according to claim 1 including first switch means in series with said resistors and second switch means in circuit with said motor, said regulating means including control means for actuating said first and second switch means in response to temperature sensed by said sensing means, and said control means including means for delaying the actuation of said second switch a predetermined period after the first switch has been actuated.
Claim 6
Dependent Claim
44 words
Heating apparatus according to claim 4 wherein said temperature sensing means is connected in a bridge connection for producing a signal proportional to deviation from a predetermined temperature and the signal is applied to the regulating means for regulating the speed of the blower.
Claim 7
Dependent Claim
24 words
Heating apparatus according to claim 5 wherein said signal is also applied to said control means to actuate said first and second switch means.
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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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |