Abstract: A thermal warning device attaches to a wheel assembly of a railway car to detect whether the wheel assembly has reached high temperatures and may lead to a potential bearing failure. A temperature sensor for monitoring the temperature of the wheel assembly is coupled to an electronic circuit for determining whether a bearing failure may occur based on the temperatures detected by the temperature sensor. In particular, the temperature sensor adjustably extends into the wheel assembly in order to obtain accurate readings of high temperatures in wheel assembly. Also, the electronic circuit is situated away from the outer surface of the wheel assembly so that the electronic circuit will not be subjected to heat from the wheel assembly and may freely dissipate heat produced by its own components. Upon determination of a warning condition, the electronic circuit transmits a warning signal to a wayside station or train crew.

Abstract: A fire detector is capable of self-detecting its own malfunction and is also capable of quickly announcing a failure of high-level emergency in the fire detector. A plurality of determining values are established for the output level of a physical quantity detector for detecting the physical quantity of a fire phenomenon such as smoke, and a different time is set for each of the determining values. A shorter time is set for greater deviation from the normal value of the output level. It is determined that the physical quantity detector is faulty if it is detected that the output level of the physical quantity detector continuously exceeds any of the established determining values for not less than the time which has been set for that particular determining value.

Abstract: A deep fat fryer includes a controller operatively connected to a heating element for controlling the operation thereof to apply heat to a cooking chamber. A temperature sensor is disposed in the cooking chamber for measuring the temperature in the cooking chamber and communicating the same to the controller. The controller selectively operates the heating means to apply heat to the cooking chamber. Utilizing the output of the temperature sensor, the controller automatically determines whether the medium contained in the cooking chamber is water, liquid shortening or solid shortening or whether the cooking chamber is empty.

Abstract: Water detection device to determine the presence of water in a cooking device having a vessel adapted to receive a cooking medium such as oil which serves as a heat transfer medium for cooking food in the vessel. The temperature of the medium in the vessel is monitored at selected intervals. The presence of water in the vessel is determined by the detection of a decrease in the rate of temperature rise in the range of the boiling point of water. In the event of a decrease in the rate of temperature rise in the range of 212 degrees Fahrenheit control functions are initiated to prevent further rise in the temperature of the vessel and initiate other necessary precautionary steps. Measurement of the rate of temperature rise can also be adapted to to eliminate the effects of certain occurrences which would tend to provide false indication of the presence of water in the vessel.

Abstract: A heat detector uses a single comparator operating in conjunction with a dynamically changing thermal reference that ensures quick response to rapid rates of thermal change and a fixed threshold that indicates an ambient temperature exceeds a threshold temperature. The inputs of the comparator receive different ones of the output signals of two thermal sensors. One thermal sensor responds nearly instantaneously to changes in ambient thermal conditions. The other thermal sensor is mounted on a printed circuit board operating as a heat sink and responds more slowly to changes in ambient thermal conditions. The difference between the thermal sensor output signals is zero at a lower ambient temperature when the rate of thermal change exceeds a preset amount and at a higher ambient temperature when the rate of thermal change is relatively slow.

Abstract: An image heating apparatus includes a heater; temperature detector for detecting a temperature of the heater; electric power supply controller for controlling electric power supply to the heater during image heating, so that the temperature detector detects a predetermined set temperature; and a temperature determining device for determining the set temperature on the basis of a change of the temperature detected by the temperature detector when electric power supply to the heater is stopped.

Abstract: An electronic heat detector provides a fire alarm with a rapid rate of rise of temperature. The rate of rise indication is obtained from a comparison of outputs from a first temperature sensor which responds rapidly to environmental temperature, referenced to a second temperature sensor which has an intermediate response between that of the first sensor and an electronics board. The second sensor is positioned within a protuberance from the heat detector housing.

Abstract: An system is provided which, in one embodiment, utilizes an identification unit to identify the contents of a container and to transmit a coded identification signal to a remote receiver unit, thereby allowing emergency personnel or other interested persons to ascertain the contents of the container at an accident site. The identification unit includes a sensor positioned within the storage cavity of the container to detect whether a predetermined unsafe temperature or pressure condition exists therein. If the condition is detected, a coded identification signal, which may be in 8-bit binary form, is generated and transmitted. In an alternate embodiment, the identification unit is modified to answer an interrogation signal transmitted by a remote interrogation device when the interrogation signal corresponds to the material stored in the associated container.

Abstract: A heat detector includes an external temperature detector for detecting an external temperature outside the heat detector and an internal temperature detector for detecting an internal temperature inside the heat detector. A microcomputer calculates a temperature difference between the external temperature detected by the external temperature detector and the internal temperature detected by the internal temperature detector. The microcomputer monitors the above-described temperature difference to detect an event in which the temperature difference has remained greater than a predetermined value for a predetermined duration or longer. If the microcomputer detects that the temperature difference has remained greater than the predetermined value for the predetermined duration or longer, the microcomputer outputs an abnormal signal representing that the external temperature detector is abnormal.

Abstract: A control/safety apparatus and method for an electrical or fuel fired water heater includes one or more temperature sensors strategically located on the water heater vessel at a level at or above a critical water level. The time rate of temperature change is calculated from the sensed temperature. An abnormal value of temperature change rate corresponding to an insufficient water level deactivates the heater to prevent damage to the heater. Water level, projected heating times, heater malfunctions and other operating parameters may be calculated or detected based on the time rate of change in sensed temperature.

Abstract: A water heating system for a commercial coffee brewer includes a control circuit having a dry bowl cut out circuit. The system includes a control circuit, tank, and heater. The dry bowl cut out circuit receives a differentiated temperature signal and generates a control signal when the differentiated signal is above a predetermined threshold. The control signal represents that the tank is empty. The heater is turned OFF in response to the control signal. Also, the control circuit includes an operating temperature circuit and high limit temperature circuit for controlling the heater. A switch in the heater is electromagnetically coupled to the control circuit.

Abstract: A safety control system for a boiling clothes washing machine has paired wash water temperature detecting devices and heater temperature detecting devices, for accurately detecting and controlling the temperature of the wash water, and for preventing the heater from overheating. One embodiment of the system, for use in a washing machine including a wash water heater, includes a first water temperature detector for detecting the temperature of wash water by means of direct contact with the wash water; a second water temperature detector for detecting the temperature of wash water by means of direct contact with the wash water; and a circuit, responsive to the second water temperature detector, for controlling the operation of the heater during an abnormal operation of the first water temperature detector.

Abstract: A method and apparatus for monitoring and limiting the operational temperature of physical and technical equipment includes supplying a heating device with at least one test pulse of energy and the effect of the test pulse on the temperature course of the equipment is compared to a characteristic operating line that is to be monitored. The comparison dictates where further energy can be supplied to the device or whether the energy supply is to be switched off. Such monitoring and control can be carried out periodically, without interrupting the operation of the equipment. The invention can be used to monitor the degree to which a heater is filled with a heat transfer medium; and is also able to detect impermissible heat dissipation levels.

Abstract: An automatic cooking method for cooking food wherein one of a timed or automatic cooking mode is selected prior starting the heating of the food upon depressing a cooking start key. The quantity or concentration of gas (e.g. carbon dioxide) or smoke emitted from the food every sampling time of a certain period is determined, and counting the time T1 taken for the quantity or concentration of gas or smoke to vary from a predetermined minimum value to a predetermined maximum value is also determined. The cooking is carried out to further heating the food for a time T2 calculated by multiplying the counted heating time T1 by a coefficient predetermined depending on the food.

Abstract: A system for controlling the temperature of a lamp annealer which system comprises a group of lamps for heating an article to be heated, a radiation thermometer for measuring the temperature of the article, and a lamp output conroller for controlling the output of the lamps based on the output of the thermometer, the controller having stored therein a target temperature control pattern.

Abstract: A dynamic temperature control to selectively generate one of a plurality of discrete voltage level temperature control signals for use with a fluid circulating system operable in a heating or cooling state including a control panel to select the system operating parameters including operating temperature of the fluid and at least one temperature sensor, the dynamic temperature control comprises logic circuitry to receive temperature input signals from the control panel and temperature sensor and to generate one of the plurality of discrete voltage level temperature control signals proportional to the difference between the input signals from the control panel and the temperature sensor to control the operating temperature of the fluid circulated through the fluid circulating system.

Abstract: A device and method for regulating a cooking apparatus. In order to obtain an effective servocontrol of the desired temperature with a cooking surface, when cooking for example by induction, a servocontrol curve is used in the plane (i.e., temperature, variation of the temperature as a function of time). Each time the curve is crossed the heating power is cut off or reduced. The device and method applies principally to monitoring of the heating device. The device according to the present invention is particularly well adapted to cooking surfaces and especially to cooking surfaces wherein cooking is done by induction.

Abstract: A cooking apparatus such as a rice cooker includes means for obtaining a value or a combination of values indicative of an amount of food that is to be cooked, and a fuzzy inference section for operating on that value or combination of values to determine a level of heating power to be supplied to a heater element of the apparatus, during at least one part of the cooking process. The amount-indicating value can be obtained for example as a rate of change of temperature of the food while it is being heated to boiling point. The apparatus can further be configured to determine a plurality of cooking control parameters, by fuzzy inference operation, based on a specified degree of final hardness of the cooked food, which can be selectively inputted by the user.

Abstract: A fire monitoring system detects a plurality of types of detection information using a plurality of fire phenomenon detectors for detecting physical quantities caused by fire phenomena or using a plurality of detectors each including at least one fire phenomenon detector and at least one environment detector provided in association with the fire phenomenon detector. The plurality of types of detection information undergo consolidated signal processing for obtaining one or more types of fire information for realizing fire monitoring.

Abstract: A fire alarm system discriminates the presence of a fire using plural likelihood ratio functions respectively associated with plural fire related phenomenon. At least one fire related condition, for example, a temperature level, a smoke density or a gas concentration, of a detected area is detected. Data denoting plural fire related phenomenon are generated based on the at least one fire related condition. The data of each fire related phenomenon is applied to a respective likelihood ratio function defining a relation between the value of the fire related phenomenon and the value of a fire likelihood ratio. The fire likelihood ratio defines a relative probability of a fire attributable to the value of the respective fire related phenomenon. Plural fire likelihood ratio values are obtained according to processing rules, and a centroid value is obtained based on the plural fire likelihood ratio values. A fire is discriminated based on the centroid value.

Abstract: A dynamic temperature control to selectively generate one of a plurality of discrete voltage level temperature control signals for use with a fluid circulating system operable in a heating or cooling state including a control panel to select the system operating parameters including operating temperature of the fluid and at least one temperature sensor, the dynamic temperature control comprises logic circuitry to receive temperature input signals from the control panel and temperature sensor and to generate one of the plurality of discrete voltage level temperature control signals proportional to the difference between the input signals from the control panel and the temperature sensor to control the operating temperature of the fluid circulated through the fluid circulating system.

Abstract: A combination fire alarm/air conditioner, which can immediately detect a fire. The device includes a temperature-sensor and/or a smoke-sensor installed in the room-side air inlet of the air conditioner. Signals generated by the sensor are received by a microcomputer which monitors them based on a threshold and a rate of change of the signals. When the rate of change of the signals exceeds the threshold, the microcomputer produces signals which set off an alarm.

Abstract: A pair of temperature detection devices having different heat time constants and an active device having a predetermined bias are connected in series. The bias is set so as to cause the active device to operate in a saturated region if the temperature is higher than a dangerous level, and to operate in a triode region if the temperature is lower than the dangerous level. The temperature detection devices are chosen so as to cause the voltage generated at the junction of the temperature detection devices to be higher than a predetermined reference voltage if the temperature has been raised to the dangerous level when the temperature is raised slowly, or if the temperature is raised rapidly, even if the temperature is lower than the dangerous level. A constant temperature function and a differential function are generated to detect that a fire has taken place.

Abstract: A smoke supervisory system comprising a visible image processor for calculating a differential image between a reference image and an input image and calculating parameters in the differential image; an address overlap detector for detecting whether the differential images overlap each other; an image element number change detector for detecting a change in the image element number of the differential image; and an address ratio change detector for calculating an address ratio of the differential image; or an equipment supervisory system comprising an image fetch device for fetching a reference image and an input image from an infrared image pick up device; a mask control device for masking the reference image and the input image; a differential operation device for calculating a differential image of an unmasked dividing image; a temperature distribution difference detector for detecting a maximum temperature and a mean temperature of a temperature distribution from the differential image and calculating a t

Abstract: A resettable fire detection device comprises in combination a rate of temperature rise sensor, an electronic fixed temperature sensor, and electronic circuitry connected to both circuits for producing an alarm signal if either sensor is activated and for maintaining the alarm signal once the device has been activated. This resettable fire detection device has many uses: specifically, it can be used as a replacement device for a smoke detector device commonly used on ships. In this case, the device draws a very low amperage for use on a parallel circuit common wih smoke detectors. In addition, a time delay circuit can be associated with each of the sensors to avoid false alarms and to accommodate certain environmental conditions. The resettable nature of both the fixed temperature and rate of rise temperatue sensor allows full testing of each device while allowing a remote reset signal to be used to reset the device. In a preferred form, the rate of temperature rise sensor is a mechanical arrangement.

Abstract: A transport refrigeration unit, and methods and apparatus for monitoring the operation thereof, with the unit conditioning a load to a selected set point temperature via commanded cooling and heating cycles. A thermostat provides a digital signal as a function of the load temperature and the selected set point temperature, with each toggling of the least significant bit (LSB) thereof indicating a predetermined change in load temperature. A timer initiates a predetermined timing period with each toggling of the LSB, with the timing period being a dynamic function of the selected set point temperature. Expiration of the timing period before the next bit toggle initiates an alarm signal indicating the rate-of-change of load temperature is not within an acceptable limit for the selected set point temperature. A comparison of successive digital signals also results in an alarm signal when the direction of temperature change is not consistent with the commanded operating cycle.

Abstract: A rapid thermal processing system is accurately controlled during a deposition process, in which the emissivity of the substrate material changes as a function of the thickness of the deposited layer, by determining the expected emissivity as a function of time during deposition and applying the expected emissivity to a controller to produce a converted temperature which controls the radiant heat sources of the rapid thermal processing system. In one embodiment, the expected emissivity is used to convert a measured pyrometer temperature into a converted pyrometer temperature. The converted pyrometer temperature is applied to a feedback controller which controls the radiant heaters so that the converted pyrometer temperature equals the desired wafer processing temperature. In another embodiment, the expected emissivity is employed to convert the desired rapid thermal processing temperature into a converted desired rapid thermal processing temperature.

Abstract: A differential fire and explosioin protection system is for a containment enclosure which receives pneumatically conveyed process air containing a combustible media. A pair of temperature sensors located in opposed relationship in the outlet duct of containment enclosure are responsive to changes in the outflow temperature at different rates. One temperature sensor has a thin metallic sheathed probe, while the other sensor is provided with a relatively thick wall sleeve in surrounding relationship to the probe. Control means connected to the temperature sensors is adapted to activate fire and/or explosion suppression or isolation equipment in response to a predetermined differential in temperature as sensed by the sensors during a certain time interval.

Abstract: A liquid heating apparatus includes a pulse combustion burner mounted to a liquid vessel and having a combustion chamber secured to a side wall of the vessel and immersed in liquid in the vessel, a tailpipe connected at its one end to an exhaust port of the combustion chamber and immersed in the liquid, and a fuel supply conduit in communication with the combustion chamber and being provided thereon with an electrically operated valve which is closed in a deactivated condition to interrupt the supply of fuel into the combustion chamber and opened in an activated condition to permit the supply of fuel into the combustion chamber.

Abstract: A temperature controller for a thermal system comprises a linearized feedback loop. A linearized thermistor and heating element are disclosed. A current source adjusts the bias current of the thermistor so that the thermistor voltage is equal to a given voltage when the thermistor is at the desired temperature. When the thermistor is biased in this way, the incremental gain from temperature errors to thermistor voltage errors becomes independent of set point. The heating element includes a power regulator and a power resistor. Because temperature is a linearly related to the power dissipated in the power resistor, square-law circuitry keeps the voltage output of the power regulator linearly related to the square root of the error in the controlled temperature. In other embodiments of the invention, a voltage source adjusts the bias voltage of the thermistor so that the incremental gain from temperature errors to thermistor current errors is independent of set point.

Abstract: A fire detector assembly comprises a base (1) and a sensor (5) adapted to fit the base. The base (1) is provided with passive means, such as pins (6) or contacts arranged in a pattern to represent an address of the detector. When the sensor (5) is fitted to the base (1), reading means in the sensor reads the address code and thereby conditions the sensor to receive appropriate signals from a control unit.

Abstract: A heating system, a deep fat fryer, control devices therefor and methods of making the same are provided, the control device comprising a temperature sensing unit for sensing the actual temperature of the output heating effect of a heat producing unit, and a setpoint unit for selecting a desired setpoint temperature that the heat producing unit is to provide with the output heating effect thereof, the control device being so constructed and arranged that the same is adapted to tend to cause the heat producing unit to provide the desired setpoint temperature with the output heating effect thereof, the control device being so constructed and arranged that the same is adapted to turn off the heat producing unit if the actual rate of change of the temperature of the output heating effect thereof is greater than a target rate of change thereof when the actual temperature of the output heating effect at that time is below the desired setpoint temperature and to turn on the heat producing unit if the actual rate of

Abstract: A new and improved level controller for sensing the level of a fluid in a container is provided. The controller includes a heater with a thermocouple connected thereto and wherein the thermocouple is adapted to sense the temperature and the rate of rise of temperature. Immersion of the thermocouple in a fluid cools the thermocouple. When the thermocouple is not immersed in the fluid it is heated by the heating element to establish an alarm condition. An alarm condition is established when the rate of rise of temperature exceeds a predetermined rate of rise and/or when the temperature exceeds a predetermined maximum temperature.

Abstract: A fire discriminating apparatus for determining whether there is the outbreak of fire in an area under surveillance in accordance with the temperature difference between a temperature detection value of the area and a reference temperature.

Abstract: An alarm system for warning of a creosote chimney fire hazard, having both means to produce a visible alarm when the creosote temperature is nearing the creosote flash point, and means to produce an audible alarm when light from actual ignition of a creosote fire is detected. The invention also provides means to discriminate against detection of wood fire light, to minimize false alarms.

Abstract: A fire alarm system of the present invention is adapted to compute an approximation equation based on the detection data from a detector or detectors such about a smoke density, a temperature, a gas concentration, etc. and predictively determine a fire based on the approximation equation. The system including computing section for computing an approximation equation approximating a change in the physical phenomenon related to the occurrence of a fire which is output from the detector or detectors, sequentially sampled and stored and for computing a future value of the phenomenon estimated from the approximation by using a predetermined number of the data stored in a storing section. The future vale is compared with a data value preliminarily set in association with the fire alarming and an alarm is generated when the relation therebetween is not within a predetermined range.

Abstract: A heating apparatus measures the operation time and the inoperative time using an operation equation to switch the magnitude of the thermal supply of the heating apparatus in accordance with the calculated values. The heating apparatus includes a heater as a heating thermal supply, a heating chamber to be heated by the heater, a driving device for controlling the supply energies to the heater, a parameter operation device for calculating, in accordance with a given operation equation, the parameter corresponding to the supply energies to the heater, an output deciding device for comparing the parameter operation value obtained by the parameter operation device with the given target value to decide the output level of the heating thermal supply.

Abstract: An automatic temperature control system for a heated roller constituting a fixing device. This control system has functions to sense the surface temperature of the heated roller, to compare with the sensed temperature and a target temperature suited for fixing toner image on a paper, and to determine a temperature gradient or a rate of temperature change with respect to time lapse of the heated roller, whereby a heater for heating the heated roller is turned on and off in accordance with the temperature state based on the comparison and the temperature gradient, that is whether the temperature of the heated roller is rising or falling. This temperature control for the heated roller is repeated on the basis of the surface temperature of the heated roller sampled by the system at fixed intervals.

Abstract: A laser thermal testing method and system for use in testing a fire alarm system which has a plurality of heat-sensors which are remotely distributed throughout a protected area. The laser thermal testing system includes a first laser and a second laser. The first laser generates an aiming beam of coherent electromagnetic radiation in the visible spectrum. The laser thermal testing system also includes a movable reflector which reflects the aiming beam. The movable reflector is optically coupled to the first laser. The movable reflector is first moved in order to align the aiming beam in an aligned position so that the aiming beam is reflected onto one of the heat-sensors. The movable reflector is then fixedly secured in the aligned position. The second laser generates a heating beam of coherent electromagnetic radiation in the infrared spectrum.

Abstract: An air condition monitor unit for monitoring the temperature and/or relative humidity of the ambient air. It comprises an air temperature sensor and a relative humidity sensor, and a plurality of memory means capable of retaining set values of respective thresholds comprising the maximum and minimum acceptable values of air temperature and relative humidity. Membrane switch means are connected to the plurality of memory means, operation of which switch means changes a set value retained in the plurality of memory means. Further membrane switch means are connected to the first switch means and the plurality of memory means, successive operation of which further switch means changes the memory means for the time being addressed by the first switch means from memory means to the next in a predetermined cycle.

Abstract: A heater unit and control circuitry therefor, the heater unit typically being employed as a preheater or primary heater for the installation and removal of electronic components from a PCB or the like and having various means for accommodating (a) an uneven surface or the presence of other components on the underside of the board or (b) an unlevel board. Moreover, a heater unit for sequentially providing preheat and primary heat from different zones of the heate is disclosed. A probe for use with the heater for sensing the temperature at various points on the board is also disclosed. The circuitry is characterized by ease of calibration of the heater temperature, the temperature transducing circuits, and the temperature setting circuits thereof. Moreover, circuitry is provided to insure the same voltage out of each input source in response to the input source measuring or setting a common temperature.

Abstract: A heating system, a deep fat fryer, control devices therefor and methods of making the same are provided, the control device comprising a temperature sensing unit for sensing the actual temperature of the output heating effect of a heat producing unit, and a setpoint unit for selecting a desired setpoint temperature that the heat producing unit is to provide with the output heating effect thereof, the control device being so constructed and arranged that the same is adapted to tend to cause the heat producing unit to provide the desired setpoint temperature with the output heating effect thereof, the control device being so constructed and arranged that the same is adapted to turn off the heat producing unit if the actual rate of change of the temperature of the output heating effect thereof is greater than a target rate of change thereof when the actual temperature of the output heating effect at that time is below the desired setpoint temperature and to turn on the heat producing unit if the actual rate of

Abstract: In an electric direct energy transfer cooker for quickly cooking food, particularly fowl such as chicken, contactably interposed between electrodes, a food doneness control circuit is connected with the supply current. The control circuit senses and stores, for reference, the peak value of the root mean square of current through the food as a function of its cooked condition and stops current to the electrodes in response to a decline in current value through the food equal to a predetermined percentage of the current peak.

Abstract: This invention relates to controlling the simmering or cooking time in a cooking vessel which can be heated by means of an electrical cooking plate with a control circuit, in which the temperature in or on the cooking vessel is determined and utilized by the control circuit to regulate the heat output of the cooking plate, in which the simmering or cooking time can be set by means of an adjustable time element, in which the cooking plate can be shut off at a length of time bvefore the completion of the predetermined simmering or cooking time which is greater the slower that the rise of the temperature in the heating phase is, and in which, by using the heat content contained inthe cooking material after shutting off the cooking plate the simmering or cooking process is extended up to the preset simmering or cooking time.

Abstract: A fire alarm system which makes fire determination based on a novel idea which considers various changes of the physical phenomena in the surroundings caused in relation with the occurrence of a fire in terms of changes of vectors. These changes in the physical phenomena are detected by the detecting section in the form of analog data and processed by a data sampling section as sampled data and stored in a storing section in such a manner as discriminating them by the detecting sections. The tendencies of the changes are computed in a first computing section and the vectors representing the present or future conditions of the physical phenomena are computed from the sampled data. The vector is compared in a comparing section with a preliminarily set data related to the fire detection and when the relation therebetween is not a predetermined one, an alarm is given through an alarming section.

Abstract: An improved temperature sensor failure detection arrangement for a temperature controlled heating device of the type having a heater, an electronic controller for controlling the power level applied to the heater, and a temperature sensor. The controller includes an internal heater energy counter, which is incremented and decremented at rates determined as a function of the power level applied to the heater such that the count of the heater energy counter approximately tracks the temperature of the heater. The controller periodically compares temperature information from the temperature sensor with the count of the heater energy counter to check for abnormal operating condition of the temperature sensor.

Abstract: In a combination heat-sensing fire detector provided with a differential diaphragm electric contact and a contact which operates at a predetermined temperature, a shape memory effect element is used as a device which operates at a predetermined temperature. The fire detector can generate a fire alarm without fail even when the ambient temperature rises very slowly.

Abstract: A microcomputer control system for a furnace is disclosed which provides accurate control of the temperature of the furnace such that the temperature can be quickly increased to a predetermined desired temperature without overshooting the desired temperature. The control system determines the tuning constants of the furnace as a function of the system's response to a predetermined input and, thereafter, uses the determined tuning constants to accurately control the temperature of the furnace. The control system employs a novel method for increasing the temperature of a furnace wherein full power is applied to the furnace heat source until the microcomputer makes the determination, based upon the furnace tuning constants, that power supplied to the furnace must be reduced to prevent the temperature of the furnace from overshooting the desired temperature.

Abstract: An alarm for a milk cooler which sounds when the temperature of milk within the cooler exceeds a predetermined value. A switch permits the device to be turned off to prevent it from sounding when milk is being discharged from the cooler or when the cooler is being cleaned with hot cleaning solvent. However when fresh milk is being introduced into the cooler that switch is overridden and the alarm sounds should the milk not be cooled to the required temperature after a predetermined interval of time.

Abstract: An improved fire alarm system utilizes receiver and fire detecting terminals connected thereto through a signal transmission line comprising two wires. The fire detecting terminal operates on two mode, one being a contact-closure mode of transmitting to the receiver a level signal whether or not a significantly higher fire-indicative quantity is detected, and the other being intelligent mode of transmitting a digital signal indicative of the sensed quantity in the form of a superimposed signal upon the level signal in answer to the instruction from the receiver for precise and convenient analysis thereof in determining fire presence on the side of the receiver. The fire detecting terminal includes a comparator having its own threshold with which the value of the sensed analog quantity is compared for providing the level-shifted signal when the sensed analog quantity has a level higher than the threshold, notifying fire presence independently of the intelligent mode.