Showing papers on "Temperature control published in 1981"

Electrically controlled programmable digital thermostat and method for regulating the operation of multistage heating and cooling systems

Abstract: An electronically controlled programmable wall thermostat provides better control of comfort temperature and permits improved energy-saving temperature setback at selected intervals of the day or night in multistage heating and cooling systems and is particularly useful in achieving improved energy savings for systems having heat pump means in the main temperature conditioning stage of the system. The thermostat includes clock means, temperature sensing means, means for displaying desired parameters of time and temperature, data entry and storage means for programming the thermostat to maintain desired temperatures during selected time intervals, and a processing means with a memory incorporating a permanently stored program instruction sequence which responds to signals from the temperature sensing means for controlling the heating and cooling systems in accordance with the time-temperature sequence programmed into the thermostat by the user. A novel method of temperature control is described in which the temperature sensing and processing means cooperate in a unique way to regulate operation of the main or heat pump stages of the heating and cooling systems relative to a programmed set temperature and to regulate operation of the auxiliary stages of the systems only with respect to the actual rate of change of temperature being effected by any operation of the system. In that way, the thermostat provides improved control of the comfort temperature under varying weather conditions and in different types of housing conditions and achieves timely and more energy-efficient recovery from setback temperatures at an optimum temperature restoring rate to result in more selective use of the heat pump means in the main stages of the systems.

Automatic temperature control device for an electric appliance such as an electric blanket

Abstract: The automatic temperature control device for an electric appliance such as an electric blanket comprises a heater element, a sensor made of a thermosensitive material having an impedance, which changes as the temperature varies, for detecting the temperature of the heater element, switching means for regulating the supply of electric power to the heater element, and a plurality of electric circuits for driving the switching means in response to the output signal from the sensor. The plurality of electric circuits function to prevent the sensor from being polarized and to detect a temperature signal by applying thereto an alternating current, to detect a failure occurring in the electric circuits in synchronism with zero-crossing pulses, and to detect a failure occurring in the switching means, thereby assuring a safe operation of the automatic temperature control device against the occurrence of any failure.

Universal temperature control circuits

Abstract: Various electronic circuits are disclosed for controlling the temperature of an object by means of a resistive heating element. Some of the circuits include a digital display for displaying the actual temperature A plurality of different temperature sensors may be used, such, for example, as a resistive sensor, a thermocouple or a thermistor. The sensor may either have a positive or a negative temperature coefficient. Since most of the sensors are not strictly linear, different means are disclosed for compensating for their nonlinearity. Some of the control circuits feature a proportional control to which may be added an anticipatory control. Less sophisticated and more inexpensive circuits simply provide an on-off control.

Selective temperature control system

Abstract: A method and apparatus is disclosed for determining the temperature to which a thermistor is exposed. A capacitor is charged through a reference resistor and the length of time required to charge the capacitor to a predetermined level is measured to obtain a reference charge time. The capacitor is discharged, and then charged through the thermistor and the length of time required to charge the capacitor to the predetermined level through the thermistor is measured to obtain a temperature charge time. The temperature to which the thermistor is exposed is determined by computing the difference between the reference charge time and the temperature charge time divided by the sum of the times.

Mixing valve arrangement

Abstract: A mixing valve arrangement for producing temperature controlled water wherein an electromagnetically actuatable supply valve is coupled in each of the hot and cold water supply lines is described. Electronic control loop circuits generate a temperature control signal from both a temperature preselector and a temperature detector and a volume control signal from both a volume preselector and a mixed water flow volume detector. An electronic decoupling circuit is interposed between the two control loop circuits and the valve actuating circuits to derive control signals representative of the degree of opening of the two supply valves from the temperature and volume control signals.

Temperature Sensor Using SAW Delay Line

Abstract: Analysis of thermal properties of quartz crystal enable to find cuts with linear frequencytemperature characteristics (JCL-cut and LSTcut). Such cuts are available to build temperature sensors with large sensitivity and good linearity. Temperature probes were built and their characteristics were measured. Measurements of response time show that they are twenty times faster than BW quartz sensors (LC-cut) for the same frequency sensitivity. SAW delay lines enable also to reach high resolution in temperature measurements. A new type of quartz thermometer is described.

Combustion selective temperature dilution

Abstract: Means are provided for controlling and modulating the temperature of the hot gas exiting the combustor associated with a gas turbine engine. The means establish a preselected temperature gradient in the hot gas so as to provide a flow of hot gas at a relatively higher temperature through gaps between adjacent turbine vanes and a flow of hot gas at a relatively lower temperature upon the vanes.

Method and apparatus for regulating the temperature of an analytical instrument reactor

Abstract: A temperature control apparatus for a high temperature reactor in an analytical instrument of the type in which a development reagent is added to a flowing stream as part of the detection process. The temperature control apparatus utilizes solid state heat transfer means to transfer heat between a thermoconductive block to which is mounted the reactor and an air exchange heat sink which obtains heat from or disposes heat into ambient air as required. The control apparatus regulates the temperature of the reactor at a very rapid rate in the high temperature range of approximately 90° C. to 150° C. without the use of a separately contained heat exchange medium. The ability of the apparatus to cool the reactor rapidly eliminates the requirement to keep reactor contents at elevated pressures to prevent vaporization of the stream being analyzed.

An analytical instrument thermoelectric temperature regulator

Abstract: A temperature control system used to precisely and accurately control the temperature of a fluid stream in an analytical system designed for investigation of the chemical constituents of the fluid stream. One example of use is in chromatography such as for the chromatographic column in an amino acid analyzer system. The temperature control system utilizes a set of thermoelectric modules to transfer heat between a thermoconductive block which holds the chromatographic column and an air exchange heat sink which obtains heat from or disposes heat into ambient air as required. The control system regulates the temperature at a very rapid rate in order to minimize the recycle time of the instrument.

Net energy transfer measurement methods, apparatus and systems with solar energy and control applications

Abstract: Heat flux sensors respectively painted black and white and mounted to a passive solar energy window intercept solar radiation and change the temperature of part of the window. The sensors, and differentially connected thermocouples attached to them, couple data to an electronic computer by which the solar radiation, reradiation, and conduction/convection thermal loss through the undisturbed balance of the window can be deduced. The computer outputs the net energy transfer NET to a recorder, a two-state indicator, and a window insulation control unit. The circuitry of the control unit responds to an ordinary thermostat and the NET from the computer to produce a condition signal, senses the position of the insulation, and repositions the insulation when necessary in response to the condition signal. The insulation is moved to block the window when the direction of NET is into the building and the inside temperature is higher than the thermostat limit temperature, and when the direction of NET is outward and the inside temperature is lower than the thermostat limit temperature.

Occupancy responsive temperature control system

Abstract: A room temperature control system includes a transmitter-receiver unit for producing an acoustic standing wave pattern in a room and for producing a signal when that pattern is disturbed by motion in the room. A logic circuit provides timing signals and interprets a pattern disturbance signal to determine whether it evidences room occupancy. The timing and interpreting sequence is initiated by a switch which detects opening and closing of the room door. Temperature control by the room thermostat is permitted when the room is occupied and control within a wider range can be provided when it is not occupied.

A pumped, two-phase flow heat transport system for orbiting instrument payloads

Abstract: A pumped two-phase (heat absorption/heat rejection) thermal transport system for orbiting instrument payloads is investigated. The thermofluid characteristics necessary for the system design are discussed. A preliminary design with a series arrangement of four instrument heat stations and six radiators in a single loop is described in detail, and the total mass is estimated to be 134 kg, with the radiators, instrument heat stations, and fluid reservoir accounting for approximately 86, 24, and 12 kg, respectively. The evaluation of preliminary test results shows that the system has potential advantages; however, further research is necessary in the areas of one-g and zero-g heat transfer coefficients/fluid regimes, fluid by-pass temperature control, and reliability of small pumps.

Optimization of operating temperature for continuous glucose isomerase reactor system

Abstract: The Optimal temperature control policy for an immobilized glucose isomerase reactor system was studied. This optimization study takes into consideration the enzyme deactivation during the continuous reactor operation. The Kinetic parameters including reduced Michaelis–Menten constant (Km), reduced maximum reaction rate (Vm), equilibrium constant (Ke), and enzyme deactivation constant (kd) and their functional relationships to temperature were determined experimentally. The optimization problem was formulated in terms of maximization of fructose productivity as the objective function. The optimization problem was solved by making use of a maximum principle and the control vector iteration method. Approximately optimal temperature control policy was employed as compared with the reactor operation at an optimum constant temperature.

Temperature control system with night setback programming as a function of temperature conditioning load

Abstract: A temperature control system for a building has a temperature responsive means or thermostat in the space for controlling a temperature conditioning apparatus furnishing temperature condition medium to the space. A time control apparatus provides for a reduction or deviation of the space temperature during certain time periods for the purpose of energy conservation and/or comfort. The space temperature is restored to the normal temperature by a pickup operation. The magnitude of temperature setback initially selected or to be maintained during the setback time period is automatically adjusted by responding to the actual building heat load, so as to keep the time and heating capacity needed to restore the space to the normal temperature within certain limits.

Process and apparatus for determination and utilization of a quantity of preheating energy

Abstract: A preheating process and apparatus for determination and utilization of a quantity of preheating energy so as to automatically achieve a desired temperature at a given location prior to a predetermined period of usage, especially for preheating an automotive vehicle. In accordance with the process, the respective preheating times required to achieve a desired temperature for various possible actual conditions at the location of usage are determined and stored, at a predetermined point of time prior to the usage commencement time, the correct preheating time is determined from the stored preheating times based upon actual temperature conditions and application of heat to the location is automatically commenced at a time prior to the usage commencement time that corresponds to the difference between the usage commencement time and the correct preheating time determined previously. In accordance with a preferred embodiment of the apparatus, a presettable timer actuated switching control means is provided for actuating a heating device. An actual temperature value sensor means is utilized to sense the actual temperature at the location to be preheated and is used to address a memory unit containing, as stored data, preheating times to be read out that correspond to the respectively required heating time to achieve a desired temperature for each of various possible actual temperatures at the location. The stored preheating time read out by the memory unit based upon actual temperature value sensed by the sensor means at a point of time prior to the preset usage commencement time is utilized by the switching control means to actuate the heating device at a time prior to a preset time for commencement of usage that corresponds to the difference between the preset usage commencement time and the time read out by the memory unit.

Dual deadband control system

Abstract: A temperature control system utilizing a plurality of heating or cooling devices to maintain the temperature at a desired level, minimizing rapid multi-stage cycling by using dual deadband zones.

Temperature control of a workpiece under ion implantation

Abstract: An end station for a material treatment apparatus such as ion implantation system employs a dish shaped disc for sequentially presenting a plurality of semiconductor wafers arranged on the periphery of the disc to an ion beam. Coolant is circulated via rotating joints through channels in a disc to maintain same at a preselected base temperature. A thin layer of thermally conductive resilient material is disposed between each semiconductor wafer and the disc. Centrifugal force acting to press the wafer against the resilient material establishes good thermal contact therebetween and further compression of the resilient material increases the thermal conductance of the layer whereby the temperature of the wafers under implantation is selectably controlled. In a closed loop system, wafer temperature and the temperature of the cooled dish-shaped disc are monitored by infrared sensor apparatus and the average wafer temperature signal is compared to a stable reference for deriving an error signal which is employed to alter the thermal impedance of the resilient layer.

Temperature control device

Abstract: PURPOSE:To eliminate the temperature variations in a room by controlling the temperature of circulating air or water in high accuracy.

High speed temperature controlled electrometer

Abstract: A high speed temperature controlled, microcircuit electrometer comprising a preamplifier with a very high resistance feedback resistor and temperature sensor on a substrate which is temperature controlled by a thermo-electric module on which the substrate is mounted and which is held within a very small temperature range by temperature control circuitry. The preamplifier, feedback resistor, temperature sensor and thermo-electric module are all enclosed in a hermetically sealed, dry gas environment, maintained at an essentially constant temperature, to reduce the effects of hostile environments, such as temperature changes, vibration, contamination, and humidity. This electrometer operates at high speed and is highly responsive to small current values such as ion currents generated by ionized gas molecules in a mass spectrometer.

Interactive dual probe temperature control system

Abstract: A dual probe interactive, control system for accurately controlling the temperature within a specified area has a controlling temperature probe located for fast response times and used in association with a controllable setpoint for modulating a heating/cooling source. An indicating/reference temperature probe is also placed in the same enclosure at an optimum location for indicating actual temperature. The actual temperature is compared to the desired temperature to detect any droop or offset and the controllable setpoint is then adjusted accordingly.

Simple control circuit for temperature regulation and other bridge applications

Abstract: A circuit is presented that makes use of low frequency square waves for exciting resistance bridges, detecting their departure from balance, and providing an output voltage for measurement or control purposes. Applications in several areas of precision metrology have been found.

Thermoelectric refrigerator having improved temperature stabilization means

Abstract: A control system for thermoelectric refrigerators is disclosed. The thermoelectric refrigerator includes at least one thermoelectric element that undergoes a first order change at a predetermined critical temperature. The element functions as a thermoelectric refrigerator element above the critical temperature, but discontinuously ceases to function as a thermoelectric refrigerator element below the critical temperature. One example of such an arrangement includes thermoelectric refrigerator elements which are superconductors. The transition temperature of one of the superconductor elements is selected as the temperature control point of the refrigerator. When the refrigerator attempts to cool below the point, the metals become superconductors losing their ability to perform as a thermoelectric refrigerator. An extremely accurate, first-order control is realized.

Adjusting the Frequency vs. Temperature Characteristics of SC-Cut Resonators by Contouring

Abstract: The effects of contouring on the frequency vs. temperature characteristics of fundamental mode and third overtone SC-cut resonators have been investigated. It has been found that the

Automotive air conditioner

Abstract: An air mixing control type air conditioner used for an automobile for controlling the diffusing air temperature so as to follow a main temperature control at an assistant driver's seat side for a main temperature control at a driver's seat side and to also maintain desired high or low temperature difference with respect to the main temperature control. Thus, the diffusing air temperature of the sub control system following the main diffusing air temperature can be controlled in a range of a predetermined constant temperature difference with respect to the main diffusing air temperature of the main control system. Accordingly, desired automotive cmpartment temperature can be obtained merely by a single main control lever.

Time-Dependent Microwave Heating and Surface Cooling of Simulated Living Tissues

Abstract: The equation of conduction of heat in a model of living tissues is solved in the case of time-dependent electromagnetic heating and surface cooling. This approach allows thermal transient phenomena in the tissue to be treated as the dynamic behavior of a linear infinite-dimension system. This approach is appropriate when the tissue temperature increase must he controlled. Some results are given in a numerical simulation.

Control system for controlling the heating of domestic water for a storage tank

Abstract: 1. Apparatus for an automatic temperature control of the water which is contained in a water storage container (1) and is heated by means of a heat exchanger (9), which is disposed outside the storage container and provided with primary and secondary circuits and is supplied on its primary side with heat energy from a heat source, wherein the water to be heated flows through the secondary circuit and is withdrawn from the storage vessel near its bottom and by a thermostat-controlled charging pump (10) is pumped through the neat exchanger and returned in a heated state near the cover, characterized in that a first thermostat (T1) is disposed in the storage container (1), preferably adjacent to the middle of the storage container, a second thermostat (T2) is connected in series with the first thermostat (T1) and disposed in the region between the cold water zone at the bottom of the storage container (1) and the entrance of the secondary circuit to the heat exchanger (9), the first thermostat (T1) energizing the charging pump (10) for the charging operation, and the second thermostat (T2) deenergizing the charging pump for terminating the charging operation, the first thermostat (T1) being closed at a predetermined first temperature of the water for consumption and the second thermostat (T2) being opened at a predetermined upper temperature of the water for consumption so that the water for consumption which is to be heated is circulated only once, and a final control element adjusting or automatically controlling the flow rate is provided in the secondary circuit.

Liquid temperature control apparatus comprising initial temperature dependent high power heater drive

Abstract: A liquid temperature control apparatus controllably heats a liquid from a temperature before a control to a desired reference temperature by varying the magnitude and/or application time period of a power for energizing a heater on the basis of a difference between a voltage corresponding to the actual temperature before a control and a reference voltage corresponding to the reference temperature. The parameter on which the magnitude and/or application time period of the heater power is to be based may be the sum of a first voltage differential between a voltage corresponding to the actual temperature before a control and the reference voltage and a second voltage differential between a voltage corresponding to an actual temperature after the start of a control and the reference voltage.

Temperature stabilization system for a radiation detector in a well logging tool

Abstract: A temperature stabilization system for a radiation detector in a well logging tool includes a temperature sensor which senses the temperature and provides a corresponding signal. Apparatus located within the logging tool and containing the radiation detector provides a controllable temperature environment for the radiation detector. A heat exchanger transfers heat from the apparatus in accordance with the temperature signal so as to stabilize the temperature in the apparatus for the radiation detector. A heat disposing device is arranged with the heat exchanger to dispose of the transferred heat.

Heattfixing device of electrophotographic copier

Abstract: PURPOSE:To enable the obtaining of fixing of high quality over the entire surface of copying paper by holding a fixing roller static until the toners soften at least CONSTITUTION:When the electric power source of the copying machine is turned on, a heater 5 is warmed up by a temperature control circuit 43 At 100 degC or less of the surface temperature of a fixing roller 3, the output line l1 is low level and the output of an AND gate 45 is low level as well, at which an electromagnetic clutch 38 is held de-energized and shut off Similarly, the output line l2 is low level as well and a main driving means 25 is held disabled When the surface temperature of the fixing roller 3 becomes 100 degC or more, the line l1 becomes high level and the line l2 is held at low level and therefore the driving circuit is abled to put the electromagnetic clutch 38 in connected state Further, the roller temperature rises and when it becomes eg 180 degC, the temperature control circuit 43 maintains that temperature at all times and the copying operation becomes possible by the operation of a print button 53