Patent US3553431A successfully refreshed from Google Patents.
US3553431A
Expired / Lapsed
US
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Control system for a heating station
Assignee: Polaroid Corp
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Filing: 1968-05-27
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Granted: 1971-01-05
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Expires: 1988-05-27
Abstract
Abstract A control system for regulating the power input to the heating station of a processing device. The system utilizes a gated, full wave thyristor to regulate an AC power input to an electrical heating element. The heating element is selected having a relatively low mass to provide fast speed heat-up to target temperatures. A positive temperature coefficient thermistor is positioned in thermal bond with the heating element and is used in conjunction with an RC storage arrangement to gate the full wave control thyristor.
Inventors
- 👤 Christian C Petersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:17
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
194 words
A control system for raising the temperature of an electrical heating element of relatively low mass and relatively high thermal response to and maintaining its temperature near a predetermined level within a short time interval comprising: a source of alternating current power; gated full wave control means connected between said power source and said heating element for varying the electrical power applied to said element; nonlinear resistor means arranged in temperature sensing relationship with said heating element and having a resistancetemperature characteristic evidencing low resistance values at temperatures below a region encompassing a narrow span of temperatures substantially near said predetermined level and evidencing a rapid rate of increase of resistance values within said region; and triggering means responsive to said resistance values and coupled with said control means gate for causing its cyclical activation in correspondence with the values of said resistance in a manner wherein said control means is activated to cause relatively lower power insertion into said heating element at temperatures within said region near said predetermined head and is activated to cause relatively higher power insertion into said heating element at temperatures within said region remote from said predetermined level.
Claim 2
Dependent Claim
194 words
A control system for raising the temperature of an electrical heating element of relatively low mass and relatively high thermal response to and maintaining its temperature near a predetermined level within a short time interval comprising: a source of alternating current power; gated full wave control means connected between said power source and said heating element for varying the electrical power applied to said element; nonlinear resistor means arranged in temperature sensing relationship with said heating element and having a resistancetemperature characteristic evidencing low resistance values at temperatures below a region encompassing a narrow span of temperatures substantially near said predetermined level and evidencing a rapid rate of increase of resistance values within said region; and triggering means responsive to said resistance values and coupled with said control means gate for causing its cyclical activation in correspondence with the values of said resistance in a manner wherein said control means is activated to cause relatively lower power insertion into said heating element at temperatures within said region near said predetermined head and is activated to cause relatively higher power insertion into said heating element at temperatures within said region remote from said predetermined level.
Claim 3
Dependent Claim
42 words
The cOntrol system of claim 1 wherein said power source is selected within a predetermined voltage range and said heating element is selected having a mass permitting its energization to evolve said temperature level by said source within said short time interval.
Claim 4
Dependent Claim
23 words
The control system of claim 1 wherein said resistor means is arranged in thermal bond with the heated environment of said heating element.
Claim 5
Dependent Claim
19 words
The control system of claim 1 wherein said resistor means is connected in thermal bond with said heating element.
Claim 6
Dependent Claim
18 words
The control system of claim 1 wherein said resistor means is selected as a positive temperature coefficient thermistor.
Claim 7
Dependent Claim
20 words
The control system of claim 1 wherein said gated full wave control means comprises a solid state, three-terminal, bidirectional thyristor.
Claim 8
Dependent Claim
35 words
The control system of claim 1 wherein said triggering means includes capacitor means coupled in charging relationship with said nonlinear resistor means and adapted to gate said control means when charged to selected voltage levels.
Claim 9
Dependent Claim
29 words
The control system of claim 7 wherein said capacitor means is coupled with a gating means connected to activate said control means upon receipt of said selected voltage level.
Claim 10
Dependent Claim
14 words
The control system of claim 8 wherein said gating means is a bilateral trigger.
Claim 11
Dependent Claim
31 words
The control system of claim 1 including: first switching means connected between said power source and said control means; and second switching means connected between said source and said triggering means.
Claim 12
Dependent Claim
57 words
The control system of claim 1 wherein said control means comprises: a solid state, three-terminal, bidirectional thyristor; and said triggering means includes capacitor means coupled in charging relationship with said nonlinear resistor means and gating means coupled between said capacitor means and said control means gate for activating said control means upon receipt of a predetermined voltage.
Claim 13
Dependent Claim
64 words
The control system of claim 1 wherein: said power source is selected within a predetermined voltage range; said heating element is selected having a mass permitting its energization to evolve said temperature level by said source within said short time interval; said nonlinear resistor means is selected as a positive temperature coefficient thermistor; and said temperature region encompasses a substantially narrow span of temperature.
Claim 14
Dependent Claim
20 words
The control system of claim 12 wherein said gated full wave control means comprises a solid state, three-terminal, bidirectional thyristor.
Claim 15
Dependent Claim
83 words
The control system of claim 1 wherein: said heating element is selected having a relatively low mass so as to permit its heat-up to said predetermined level within said short time interval; said resistor means is selected as a positive temperature coefficient thermistor; said temperature region encompasses a substantially narrow span of temperature; and said triggering means includes capacitor means coupled in charging relationship with said positive temperature coefficient thermistor and adapted to gate said control means when charged to selected voltage levels.
Claim 16
Dependent Claim
29 words
The control system of claim 14 wherein said capacitor means is coupled with a gating means connected to activate said control means upon receipt of said selected voltage level.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |