Patent
Temperature sensing circuit with high noise immunity
TLDR
In this paper, the average temperature of the cabinet air is measured using a thermistor and a potentiometer, and a second comparator is interposed between the first comparator and the second comparators to provide high noise immunity.Abstract:
A refrigerator includes a compressor, a condenser, an evaporator, an evaporator fan and a temperature sensing circuit which includes a thermistor located to sense the average temperature of the cabinet air and a potentiometer manually adjustable to a desired temperature set point. The temperature sensing circuit also includes a first comparator stage which indicates whether the average temperature of the cabinet air is above or below a first value, the first comparator having little or no hysteresis in its response so that small changes in temperature can be detected. A second comparator stage indicates whether a signal at its input is greater or less than a second value, the second comparator stage having substantial hysteresis in its response to provide high noise immunity. An integrator is interposed between the first comparator stage and the second comparator stage to further enhance noise suppression.read more
Citations
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Patent
Electronic clinical thermometer
TL;DR: An electronic clinical thermometer which uses a small quantity of corrective data for correcting a non-linear output into a linear output to produce a correct temperature reading, and which includes a temperature sensing unit, a corrective data storage unit and an adder is described in this paper.
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Two speed control circuit for a refrigerator fan
TL;DR: In this paper, an apparatus for driving a fan as part of a refrigerator is described, where a temperature sensor is positioned in association with the compartment and outputs a sensed temperature signal as a function of the temperature in the compartment.
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Proportional integral cooling device controller for electronic device
TL;DR: In this paper, the cooling rate of the cooling device is varied by the control circuit in proportion to variation in sensed component temperature from the temperature sensor, which cancels out a lag time which occurs during a change from a steady state condition of the component temperature.
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TL;DR: In this article, a refrigeration controller is provided which thermostatically controls a refrigerated compartment temperature, and a heated evaporator is provided within a certain wattage range to accelerate defrosting.
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Selective temperature control system
TL;DR: In this article, a method and apparatus for determining the temperature to which a thermistor is exposed was described, and the length of time required to charge the capacitor to the predetermined level through the thermistor was measured to obtain a temperature charge time.
References
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Patent
Air conditioner control
TL;DR: In this paper, the malfunction indicator and reset control are disposed adjacent the thermostat for facilitated determination of the system operating condition, where clock pulses and R-C time delays are used to facilitate operation of the current sensing control.
Patent
Refrigeration control system
TL;DR: In this paper, a control system automatically changes the refrigerant flow through the evaporator to establish the evaporator outlet temperature at the control point required to maintain the controlled space at the desired temperature.
Patent
Thermostat chatter protection for refrigeration compressor motors
TL;DR: In this paper, the motor relay is energized or de-energized by a solid state switch, which is controlled by two or more trip circuits in response to a condition of operation of the system.
Patent
Control system for heating and/or cooling system
TL;DR: In this article, a control system for thermal (heating and/or cooling) equipment is disclosed in two embodiments both of which employ a thermistor to derive a temperature voltage signal and at least two Op-Amp comparator circuits driven by that signal and different reference signals to operate thermal equipment switching means.
Patent
Temperature controller for controlling both heating and cooling
TL;DR: In this paper, a temperature controller for maintaining the temperature of a process at a set point by controlling the heating input in accordance with both a proportional and reset response from the temperature deviation is presented.