Patent US3553429A successfully refreshed from Google Patents.
US3553429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature control circuit
Assignee: Eastman Kodak Co
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Filing: 1968-11-18
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Granted: 1971-01-05
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Expires: 1988-11-18
Abstract
Abstract A temperature control circuit for accurately controlling the temperature of a medium includes a bridge which senses the temperature of the medium. The bridge supplies a signal representative of the temperature difference between the desired temperature and the actual temperature of the medium to a differential amplifier. A network coupled to the differential amplifier provides a visual indication of the temperature difference and amplifies the signal received from the differential amplifier. A relaxation oscillator network is coupled to the network to operate a triac. The triac controls a heater and thus regulates the temperature of the medium.
Inventors
- 👤 Raymond L Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:17
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
297 words
Electronic temperature control means for detecting the temperature of a medium and for regulating the temperature of the medium with respect to a reference temperature by operating an electrically operative regulating device, said control means comprising: a. semiconductive switching means for controlling current flow to the regulating device, said switching means having a control terminal; and b. a control circuit coupled to said control terminal for operating said switching means, said control circuit comprising: 1. sensing means for producing a signal indicative of a temperature differential between the temperature of said medium and the reference temperature, said sensing means having a portion positionable in heat sensing relation to the medium to detect the temperature of the medium; 2. differential amplification means having an input coupled to said sensing means and an output, said amplification means being operative to receive and amplify said signal generated by said sensing means; 3. a network having an input coupled to the output said differential amplification means for receiving an amplified signal therefrom, said network comprising second amplification means for further amplifying said signal, and having indication means for indicating a temperature differential sensed by said sensing means, said indication means being coupled directly to the output of the differential amplifier for receiving the amplified signal from the differential amplifier means and prior to further amplification of such signal by the second amplification means, said network further comprising a variable resistance connected within said network so that adjustment of the variable resistance determines the reference temperature; and 4. means having an input coupled to said network for receiving an amplified signal therefrom, and said last means having an output coupled to said control terminal of said semiconductive switching means for operating said switching means in response to a signal from said network.
Claim 2
Dependent Claim
297 words
Electronic temperature control means for detecting the temperature of a medium and for regulating the temperature of the medium with respect to a reference temperature by operating an electrically operative regulating device, said control means comprising: a. semiconductive switching means for controlling current flow to the regulating device, said switching means having a control terminal; and b. a control circuit coupled to said control terminal for operating said switching means, said control circuit comprising: 1. sensing means for producing a signal indicative of a temperature differential between the temperature of said medium and the reference temperature, said sensing means having a portion positionable in heat sensing relation to the medium to detect the temperature of the medium; 2. differential amplification means having an input coupled to said sensing means and an output, said amplification means being operative to receive and amplify said signal generated by said sensing means; 3. a network having an input coupled to the output said differential amplification means for receiving an amplified signal therefrom, said network comprising second amplification means for further amplifying said signal, and having indication means for indicating a temperature differential sensed by said sensing means, said indication means being coupled directly to the output of the differential amplifier for receiving the amplified signal from the differential amplifier means and prior to further amplification of such signal by the second amplification means, said network further comprising a variable resistance connected within said network so that adjustment of the variable resistance determines the reference temperature; and 4. means having an input coupled to said network for receiving an amplified signal therefrom, and said last means having an output coupled to said control terminal of said semiconductive switching means for operating said switching means in response to a signal from said network.
Claim 3
Dependent Claim
30 words
differential amplification means having an input coupled to said sensing means and an output, said amplification means being operative to receive and amplify said signal generated by said sensing means;
Claim 4
Dependent Claim
30 words
differential amplification means having an input coupled to said sensing means and an output, said amplification means being operative to receive and amplify said signal generated by said sensing means;
Claim 5
Dependent Claim
83 words
Electronic temperature control means according to claim 1 wherein said amplification means of said network comprises a transistor having an emitter and a base; said variable resistance of said network comprises a potentiometer coupled to the emitter of said transistor and being adapted to be coupled to a DC voltage supply; said potentiometer having a sweeper arm connected through a resistor to said base of said transistor; said sweeper arm being adjustable to vary the bias current to said base of said transistor.
Claim 6
Dependent Claim
25 words
a differential amplifier network connected across said bridge for receiving a signal indicative of said temperature differential from said bridge and for amplifying that signal,
Claim 7
Dependent Claim
25 words
a differential amplifier network connected across said bridge for receiving a signal indicative of said temperature differential from said bridge and for amplifying that signal,
Claim 8
Dependent Claim
73 words
a network operatively connected to said differential amplifier and having amplification means for amplifying the signal received from the differential amplifier, said network further comprising visual indication means for providing a measurement of said temperature differential prior to amplification of the signal received by the network from the differential amplifier, said network further comprising a variable resistance connected in the network so that adjustment of the variable resistance adjusts the reference temperature; and
Claim 9
Dependent Claim
73 words
a network operatively connected to said differential amplifier and having amplification means for amplifying the signal received from the differential amplifier, said network further comprising visual indication means for providing a measurement of said temperature differential prior to amplification of the signal received by the network from the differential amplifier, said network further comprising a variable resistance connected in the network so that adjustment of the variable resistance adjusts the reference temperature; and
Claim 10
Dependent Claim
26 words
Electronic temperature control means according to claim 1 wherein said indication means of said network comprises a milliammeter coupled to the output of said amplifying means.
Claim 11
Dependent Claim
103 words
a network having an input coupled to the output said differential amplification means for receiving an amplified signal therefrom, said network comprising second amplification means for further amplifying said signal, and having indication means for indicating a temperature differential sensed by said sensing means, said indication means being coupled directly to the output of the differential amplifier for receiving the amplified signal from the differential amplifier means and prior to further amplification of such signal by the second amplification means, said network further comprising a variable resistance connected within said network so that adjustment of the variable resistance determines the reference temperature; and
Claim 12
Dependent Claim
103 words
a network having an input coupled to the output said differential amplification means for receiving an amplified signal therefrom, said network comprising second amplification means for further amplifying said signal, and having indication means for indicating a temperature differential sensed by said sensing means, said indication means being coupled directly to the output of the differential amplifier for receiving the amplified signal from the differential amplifier means and prior to further amplification of such signal by the second amplification means, said network further comprising a variable resistance connected within said network so that adjustment of the variable resistance determines the reference temperature; and
Claim 13
Dependent Claim
44 words
means having an input coupled to said network for receiving an amplified signal therefrom, and said last means having an output coupled to said control terminal of said semiconductive switching means for operating said switching means in response to a signal from said network.
Claim 14
Dependent Claim
44 words
means having an input coupled to said network for receiving an amplified signal therefrom, and said last means having an output coupled to said control terminal of said semiconductive switching means for operating said switching means in response to a signal from said network.
Claim 15
Dependent Claim
84 words
Electronic temperature control means according to claim 1 wherein said means coupled to said network comprises a unijunction 4, having an emitter, said means further comprises a capacitor coupled between said emitter of said unijunction transistor and said control terminal of said semiconductive switching means so that said capacitor will discharge rapidly through the unijunction transistor when charged to said threshold potential of said unijunction transistor, thereby generating a negative pulse at said control terminal of said switching means for regulating said switching means.
Claim 16
Dependent Claim
64 words
relaxation oscillation circuitry coupled to said network for receiving an amplified signal therefrom, said relaxation oscillation circuitry being operable to generate a negative pulse in response to the signal received from said network, and said relaxation oscillation circuitry being coupled to said control terminal of said triac so that the generating of a negative pulse in response to said amplified signal operates said triac.
Claim 17
Dependent Claim
64 words
relaxation oscillation circuitry coupled to said network for receiving an amplified signal therefrom, said relaxation oscillation circuitry being operable to generate a negative pulse in response to the signal received from said network, and said relaxation oscillation circuitry being coupled to said control terminal of said triac so that the generating of a negative pulse in response to said amplified signal operates said triac.
Claim 18
Dependent Claim
29 words
Electronic temperature control means according to claim 1 further comprising a rectifier power supply coupled to said control circuitry and adapted to be coupled to an AC power supply.
Claim 19
Dependent Claim
59 words
Electronic temperature control means for detecting the temperature of a medium and for regulating the temperature of the medium by operating a heater, Said control means comprising: a. a triac for controlling current flow to the heater, said triac having a control terminal: and b. control circuitry coupled to said triac for operating said triac, said control circuitry comprising;
Claim 20
Dependent Claim
59 words
Electronic temperature control means for detecting the temperature of a medium and for regulating the temperature of the medium by operating a heater, Said control means comprising: a. a triac for controlling current flow to the heater, said triac having a control terminal: and b. control circuitry coupled to said triac for operating said triac, said control circuitry comprising;
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 |