US4031355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-channel temperature responsive process control system
Assignee: Individual
•
Filing: 1975-03-31
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Granted: 1977-06-21
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Expires: 1995-03-31
Abstract
Abstract A solid state multi-channel temperature responsive control system having thermocouples positioned to monitor the temperature at various process control locations. Each thermocouple generates an electrical sensor signal representing the monitored temperature at the corresponding control location. The sensor signal from each thermocouple is supplied to an associated channel of control circuitry which automatically compares the sensor signal with a manually adjustable set-point signal representing the desired temperature at the monitored control location. The sensor signal for any particular channel may be selectively displayed on a voltmeter calibrated in degrees of temperature, and the set-point signal for the selected channel may be displayed on the same meter to facilitate adjustment thereof. The comparison circuitry in each channel generates a difference signal reflecting variation of the monitored temperature from its set-point value. The difference signal controls an associated but electrically isolated switching circuit, to regulate the application of alternating current to a control means associated with the channel. In the disclosed embodiment such control means include electrothermal and electromechanical transducers. Provision is included for visual high/low condition alarm indication, thermocouple break protection and cold junction compensation.
Inventors
- 👤 Stephen A. Leonik, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:34
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/22; G05D23/1927; G05D23/193; G05D23/1932
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
152 words
A control system comprising: a sensor producing electrical signals representing a controllable physical condition; a circuit including a first integrated circuit feedback amplifier having an input connected to said sensor for amplifying said sensor signals and a second like integrated circuit feedback amplifier having an input potentiometer connected across a power supply for adjusting the input thereto for producing set condition signals; a meter selectively connected to receive and display said amplified sensor signals and said set condition signals in terms of the condition to be controlled; a comparator comprising a third integrated circuit feedback amplifier connected to receive said amplified sensor signals and said set condition signals and producing a difference signal therefrom; a switch connecting a power supply and an operator for affecting the condition to be controlled; and an optical coupler applying said difference signal to control means of said switch for operating the switch to control said condition.
Claim 2
Dependent Claim
152 words
A control system comprising: a sensor producing electrical signals representing a controllable physical condition; a circuit including a first integrated circuit feedback amplifier having an input connected to said sensor for amplifying said sensor signals and a second like integrated circuit feedback amplifier having an input potentiometer connected across a power supply for adjusting the input thereto for producing set condition signals; a meter selectively connected to receive and display said amplified sensor signals and said set condition signals in terms of the condition to be controlled; a comparator comprising a third integrated circuit feedback amplifier connected to receive said amplified sensor signals and said set condition signals and producing a difference signal therefrom; a switch connecting a power supply and an operator for affecting the condition to be controlled; and an optical coupler applying said difference signal to control means of said switch for operating the switch to control said condition.
Claim 3
Dependent Claim
41 words
The control system of claim 1 further defined by said power supply comprising an alternating current power supply and said switch comprising a zero voltage switch whereby said power supply is only switched at the phase condition of zero voltage therefrom.
Claim 4
Dependent Claim
60 words
The control system of claim 1 further defined by said sensor comprising a thermocouple for producing signals related to temperature, said first amplifier having a thermistor in an input circuit thereof connected to said thermocouple, and said meter comprising a voltmeter having a visually observable indicator calibrated in degrees of temperature and indicating an adjustable set temperature at the thermocouple.
Claim 5
Dependent Claim
44 words
The system of claim 1 further defined by said sensor comprising a thermocouple, a voltage divider connected across the input of said first amplifier and a biasing circuit including a thermistor connected to bias said voltage divider for cold junction compensation of said thermocouple.
Claim 6
Dependent Claim
43 words
The system of claim 1 further defined by said sensor having a low electrical resistance and a voltage divider connected across a power supply and to the input of said first amplifier for applying a very different input signal thereto upon sensor failure.
Claim 7
Dependent Claim
198 words
A control system for automatically controlling a physical condition at a plurality of locations comprising a sensor disposed at each of said locations responsive to a condition to be controlled and producing electrical signals related to such condition; a plurality of channels having a sensor connected to the input of each and each including first, second and third amplifiers with the associated sensor connected across the first amplifier to produce a channel sensor signal and a potentiometer connected across the second amplifier to produce an adjustable channel set signal, said third amplifier being connected to receive said sensor and set signals to produce a difference signal therefrom and channel switching means coupled to said third amplifier for controlling an operator effecting said physical condition at the location of the channel sensor; a meter; and system switching means including a first selector switch connecting said meter to a selected channel and a two position switch for each channel to connect either said channel sensor signal or channel set signal to said meter, whereby the set signal for each channel may be adjusted as indicated by said meter to the desired location condition and such condition is then automatically maintained.
Claim 8
Dependent Claim
198 words
A control system for automatically controlling a physical condition at a plurality of locations comprising a sensor disposed at each of said locations responsive to a condition to be controlled and producing electrical signals related to such condition; a plurality of channels having a sensor connected to the input of each and each including first, second and third amplifiers with the associated sensor connected across the first amplifier to produce a channel sensor signal and a potentiometer connected across the second amplifier to produce an adjustable channel set signal, said third amplifier being connected to receive said sensor and set signals to produce a difference signal therefrom and channel switching means coupled to said third amplifier for controlling an operator effecting said physical condition at the location of the channel sensor; a meter; and system switching means including a first selector switch connecting said meter to a selected channel and a two position switch for each channel to connect either said channel sensor signal or channel set signal to said meter, whereby the set signal for each channel may be adjusted as indicated by said meter to the desired location condition and such condition is then automatically maintained.
Claim 9
Dependent Claim
193 words
An adjustable automatic temperature control system comprising at least one thermocouple adapted for placement of a sensing end thereof at a location for temperature control and producing signals at an output end thereof related to the actual temperature at said location. a first amplifier having an input circuit connected to the output end of said thermocouple and producing an amplified thermocouple signal, a second amplifier having an input potentiometer connected across a power supply to apply a controllable input signal thereto, a meter connected through a selector switch to the outputs of said first and second amplifiers for selectively displaying the amplifier output signals as temperatures whereby the second amplifier output is adjustable to represent a desired temperature at said location, a comparator connected to the outputs of said amplifiers and producing a difference signal therefrom, an electronic switch connecting a power supply to heating coils disposable in proximity to said location for energizing the heating coils in response to switch actuation, and an optical coupler connecting the difference signals from said comparator to said switch for controlling actuation thereof to control the temperature at said location by controlling heating by said coils.
Claim 10
Dependent Claim
193 words
An adjustable automatic temperature control system comprising at least one thermocouple adapted for placement of a sensing end thereof at a location for temperature control and producing signals at an output end thereof related to the actual temperature at said location. a first amplifier having an input circuit connected to the output end of said thermocouple and producing an amplified thermocouple signal, a second amplifier having an input potentiometer connected across a power supply to apply a controllable input signal thereto, a meter connected through a selector switch to the outputs of said first and second amplifiers for selectively displaying the amplifier output signals as temperatures whereby the second amplifier output is adjustable to represent a desired temperature at said location, a comparator connected to the outputs of said amplifiers and producing a difference signal therefrom, an electronic switch connecting a power supply to heating coils disposable in proximity to said location for energizing the heating coils in response to switch actuation, and an optical coupler connecting the difference signals from said comparator to said switch for controlling actuation thereof to control the temperature at said location by controlling heating by said coils.
Claim 11
Dependent Claim
60 words
The system of claim 8 further defined by said first and second amplifiers and said comparator comprising like integrated circuit amplifiers, a transistor coupling the output of said comparator to said optical coupler, and said electronic switch including a zero voltage switch operated by said optical coupler and controlling at least one thyristor connecting said power supply and heating coils.
Claim 12
Dependent Claim
44 words
The system of claim 8 further defined by a heat conducting frame mounting said amplifiers, coupler and electronic switch with said thyristor being directly attached to said frame at 25 to 30 percent of the vertical height thereof from the bottom of the frame.
Claim 13
Dependent Claim
197 words
A multi-channel electronic control system responsive to the temperature at each of a plurality of process control locations, each of said channels being associated with a corresponding one of said control locations and individually comprising: a thermocouple at said associated control location for generating electrical output signals representative of the monitored temperature thereat; control means for affecting a controllable physical condition associated with the monitored temperature at said control location; first control circuit means responsive to said thermocouple output signals for amplifying said signals to generate a sensor signal therefrom; second control circuit means responsive to manual adjustment to generate a selectively variable set-point signal representative of the desired temperature at said monitored control location; third control circuit means responsive to said sensor signal from said first circuit means and to said set-point signal from said second circuit means for comparing said signals to generate a difference signal therefrom; power switching circuit means responsive to said difference signal to selectively supply alternating current electrical power to said control means when said difference signal exceeds a predetermined value; and means for selectively displaying said sensor signals and said set point signals for a selected one of said channels.
Claim 14
Dependent Claim
197 words
A multi-channel electronic control system responsive to the temperature at each of a plurality of process control locations, each of said channels being associated with a corresponding one of said control locations and individually comprising: a thermocouple at said associated control location for generating electrical output signals representative of the monitored temperature thereat; control means for affecting a controllable physical condition associated with the monitored temperature at said control location; first control circuit means responsive to said thermocouple output signals for amplifying said signals to generate a sensor signal therefrom; second control circuit means responsive to manual adjustment to generate a selectively variable set-point signal representative of the desired temperature at said monitored control location; third control circuit means responsive to said sensor signal from said first circuit means and to said set-point signal from said second circuit means for comparing said signals to generate a difference signal therefrom; power switching circuit means responsive to said difference signal to selectively supply alternating current electrical power to said control means when said difference signal exceeds a predetermined value; and means for selectively displaying said sensor signals and said set point signals for a selected one of said channels.
Claim 15
Dependent Claim
15 words
The control system of claim 10 wherein said control means further comprise electrothermal transducer means.
Claim 16
Dependent Claim
16 words
The control system of claim 11 wherein said electrothermal transducer means further comprise resistive heating elements.
Claim 17
Dependent Claim
42 words
The control system of claim 12 wherein said power switching circuit means includes a zero voltage switch whereby electrical power is supplied to said heating elements only during the period of the AC cycle when the voltage component thereof is near zero.
Claim 18
Dependent Claim
15 words
The control system of claim 10 wherein said control means further comprise electromechanical transducer means.
Claim 19
Dependent Claim
21 words
The control system of claim 14 wherein said electromechanical transducer means further comprises at least one solenoid actuated fluid flow valve.
Claim 20
Dependent Claim
22 words
The control system of claim 10 further comprising electrical isolation means between said control circuit means and said power switching circuit means.
Claim 21
Dependent Claim
16 words
The control system of claim 16 wherein said electric isolation means further comprises an optical coupler.
Claim 22
Dependent Claim
25 words
The control system of claim 10 wherein said selective display means further comprises a voltmeter having a visually observable indicator calibrated in degrees of temperature.
Claim 23
Dependent Claim
31 words
The control system of claim 10 wherein said first control circuit means includes a thermistor associated with the input thereof to compensate for cold junction effects on said thermocouple output signal.
Claim 24
Dependent Claim
24 words
The control system of claim 10 wherein said second control circuit means includes a manually adjustable potentiometer for selective variation of said set-point signal.
Claim 25
Dependent Claim
29 words
The control system of claim 10 further comprising visual alarm means for indicating deviation of the magnitude of said sensor signal from said set-point signal by a predetermined amount.
Claim 26
Dependent Claim
52 words
The control system of claim 21 wherein said visual alarm means further comprises a light emitting diode exhibiting a first color illumination when said sensor signal exceeds said set-point signal by a predetermined amount and a second color illumination when said sensor signal falls below said set-point signal by a predetermined amount.
Claim 27
Dependent Claim
93 words
The control system of claim 10, wherein said first and second control circuits respectfully comprise first and second like integrated circuit feedback amplifiers, said first amplifier having an input connected to receive said thermocouple output signal and said second amplifier having an input connected to a mannually adjustable potentiometer, and wherein said third control circuit further comprises a third integrated circuit feedback amplifier, one input of which is connected to receive the output of said first amplifier and the other input of which is connected to receive the output of said second amplifier.
Claim 28
Dependent Claim
193 words
In liquid adhesive dispensing apparatus of the type having a tank for containing a quantity of liquid adhesive, an applicator for dispensing said adhesive onto a work surface and adhesive supply means connecting said tank and said applicator, the improvement comprising an electronic multi-channel control system responsive to adhesive temperature at a plurality of thermal flow locations including said tank, said supply means and said applicator, wherein each channel of said control system is associated with one of said thermal flow locations and further comprises: a. a thermocouple at the associated thermal flow loaction for monitoring the temperature thereat and generating an electrical output signal representing said monitored temperature; b. a control circuit for comparing said thermocouple output signal with a manually adjustable set-point signal representing the desired temperature at said thermal flow location to generate a control signal therefrom whenever the relative magnitude of said thermocouple signal and said set-point signal exceeds a predetermined amount; c. control means affecting the monitored temperature at said thermal flow location; and d. an electronic power switch responsive to said control signal to supply electrical power to said control means upon receipt of said control signal.
Claim 29
Dependent Claim
193 words
In liquid adhesive dispensing apparatus of the type having a tank for containing a quantity of liquid adhesive, an applicator for dispensing said adhesive onto a work surface and adhesive supply means connecting said tank and said applicator, the improvement comprising an electronic multi-channel control system responsive to adhesive temperature at a plurality of thermal flow locations including said tank, said supply means and said applicator, wherein each channel of said control system is associated with one of said thermal flow locations and further comprises: a. a thermocouple at the associated thermal flow loaction for monitoring the temperature thereat and generating an electrical output signal representing said monitored temperature; b. a control circuit for comparing said thermocouple output signal with a manually adjustable set-point signal representing the desired temperature at said thermal flow location to generate a control signal therefrom whenever the relative magnitude of said thermocouple signal and said set-point signal exceeds a predetermined amount; c. control means affecting the monitored temperature at said thermal flow location; and d. an electronic power switch responsive to said control signal to supply electrical power to said control means upon receipt of said control signal.
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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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |