Abstract: An improved fire detector vented to atmosphere, capable of closing or opening an alarm circuit on the happening of either two events, when the rate of rise of the temperature of the ambient atmosphere exceeds a predetermined prescribed rate of rise of temperature and when the temperature of the ambient atmosphere exceeds a predetermined fixed temperature, the detector being of the type comprising a base supporting a diaphragm enclosing a space between the base and diaphragm, a shell secured to the base enclosing the diaphragm, vent apertures through the base from the space between the diaphragm and shell, and between the diaphragm and base, to the back of the detector, and a fin for collecting heat from the ambient atmosphere. The vent aperture permits the spaces between the diaphragm and base, and shell and base to be vented to atmosphere under normal expansion and contraction of the ambient atmosphere.

Abstract: A regulator circuit for controlling the heat output of a heating element adapted to be switched on and off by a semiconductor switch energized by a zero crossing switch having cycle group control, whereby a sensor signal derived from the sensed temperature is supplied to the zero crossing switch. In order to avoid an overriding of the control or operating temperature in the heating phase and to improve the accuracy of the temperature control, a secondary control voltage is derived from the sensor voltage according to the rate of rise and drop of the sensor voltage which in the heat phase the switch-off of the heating element is reset to lower temperatures depending on the secondary control voltage and in the cooling phase the switch-on of the heating element is reset to higher temperatures depending on the secondary control voltage.

Abstract: A device for regulating the cooking process in a cooking vessel which is heated by a heating element provided with a control circuit. The temperature in the cooking vessel is measured and is utilized by the control circuit to regulate the heating element. The cooking time can be preset by an adjustable timer. The cooking time in the cooking vessel is made independent of the inertia inherent in the cooking system by causing the timer to start metering the preset cooking time only after the cooking temperature has been reached. The operation of the timer may be governed by the slope of the temperature-time curve during the heating phase to enable the timer to shut off the heating element prematurely, relative to the preset cooking time, as the temperature-time curve rises less steeply during the heating phase.

Abstract: A fire detector which outputs a change in physical phenomena caused by fire, such as a change in smoke density, in the form of analog voltage signal, by, for example, a photoelectric type sensor, an ionization type sensor, a thermal sensor, a gas sensor or the like, converts the output voltage into a pulse width corresponding to the voltage level by a voltage-pulse width converting circuit, counts quick clock pulses over the pulse width by a pulse counter, and transmits the count output from the pulse counter, in the form of digital signal, to a central signal station.

Abstract: The device of the invention serves for the temperature regulation of an element heated by means of a heat source and whose temperature is measured by means of a detector. Said device includes a digital processor supplying a programmed reference digital signal. It further comprises a D/A converter transforming said digital signal into an analog reference signal, a subtractor which receives this reference signal and the one supplied by the detector, an A/D converter transforming the difference signal .epsilon. into a digital signal, processing structure for elaborating a correction signal as a function of an anticipated energy difference and a power control circuit for the energy source responsive to said correction signal.

Abstract: A process and apparatus to control the cooking process in a steam pressure cooker heated with a heating element controlled through a control circuit wherein the temperature of the pressure cooker is detected and utilized by the control circuit to regulate the heat output of the heating element, and wherein a cooking time can be preset by means of an adjustable timing element.

Abstract: A display arrangement for a cooking appliance using a heater energy counter based power control system which provides a user discernible signal signifying that the appliance heating element has reached the steady state temperature associated with the user selected power setting. The heater energy counter is selectively incremented or decremented at a rate in accordance with the selected power setting such that the count rate is approximately proportional to the rate of increase or decrease respectively of the temperature of the heating element for the power setting selected. When so incremented and decremented the count of the counter provides an approximation of the actual heating element temperature. The display arrangement generates a user discernible signal when the count of the heater energy counter indicates that the associated heating element has approximately reached the steady state temperature for the selected power setting.

Abstract: An apparatus for monitoring the cooking process in a cooking vessel placed on an electric heating element, particularly a stovetop burner, comprising signal transmitter controlled by the temperature in the cooking vessel, a signal receiver in communication with the signal transmitter by a transmitter for activating a control circuit to adjust the heat output of the heating element, and a switch for turning the apparatus on and off. During the entire cooking operation and when the heating element is set at full heating capacity, a periodical surveillance is effected to determine whether the temperature varies, remains steady or decreases. If a temperature increase is measured during a monitoring cycle, the heating element is not turned off, but if the temperature remains constant or falls, the heating element is turned off.

Abstract: A device for the control of the cooking process in a steam pressure cooker filled with water and the food to be cooked and heatable by means of a heating element controlled by a control circuit wherein the temperature of the pressure cooker is detected and utilized by way of the control circuit for the adjustment of the heat output of the heating element and in which by means of an adjustable timing element a cooking time can be preselected.

Abstract: A system to control and regulate heat output during the heat-up phase of a pressure cooker heated by a heating element which can be turned on and off by means of a control circuit. The heat-up phase is adjusted, depending on the rate of temperature increase before it reaches the boiling temperature, and is controlled by a different program after the boiling temperature is reached, which determines rates of further temperature increases and also the temperature differentials between a preset cooking temperature and the current cooking temperature. Using this apparatus, the cooking temperature can be reached as quickly as possible, regardless of the characteristics of the heating phase, dependent upon the type and amount of cooking material in the pressure cooker. Energy utilization efficiency can be increased and the preset cooking temperature not exceeded.

Abstract: An improved fire detector appropriately vented to atmosphere is provided, the detector comprising a base supporting a diaphragm enclosing a space between the base and diaphragm, a shell secured to the base enclosing the diaphragm, and a fin for collecting heat from the ambient atmosphere, secured by a ferrule to the shell. A vent aperture is provided through the base from the space between the diaphragm and the base to the back of the detector and which detector is covered by a closure cap. The fin is secured to the shell by a ferrule by causing peripheral portions of the end of the ferrule proximate the central aperture of the fin through which the ferrule is inserted to be forced to be indented to cause metal from such peripheral portions to flow radially over portions of the fin.

Abstract: Heating apparatus particularly for flameless atomization in spectrophotometers includes a variable electrical power source and a resistive heating element. A desired final temperature and the rate of change of the element temperature (ramp rate) is input to a control circuit. A storage means is provided for storing data relating the heating element temperature to the energy input (voltage) to the heating element required to maintain the heating element at a constant temperature. Processing means calculates from the various data the voltage required to be supplied to the element by the power source to change the temperature thereof at the selected ramp rate until it reaches the final temperature. In spectrophotometers the apparatus accurately controls the carbon rod temperature through drying, ashing and atomizing stages.

Abstract: Instead of monitoring a thermal deburring operation by reference to whether a certain high temperature is reached and thereby indicting whether a successful ignition in the deburring chamber has taken place at every step of operation of the chamber, a circuit responsive to the rate of change of temperature is used to recognize a successful operation, thus permitting faster operation of the apparatus. Such a circuit is also useful for rapid detection of a short circuit circuit in electrochemical apparatus utilizing heavy electrical currents and variable amounts. In the latter case a digital circuit for measuring the amount of change at equal intervals of time is particularly useful.

Abstract: A perimeter heat loss control system for electrical heaters and/or radiant ceiling panels around the periphery of a building has the heaters divided into zones, usually one zone for each outside wall. In a zone, a radiant heat responsive heat flow sensor faces the outside wall for the zone and generates a wall heat rate signal; a thermal sensor is positioned adjacent to one heater to generate a heat rate signal. A zone comparator uses the sensor signals to generate an error signal representative of deviation of the differential between the rate of heat flow through the zone wall and the rate of heat generation in the zone relative to a predetermined preset value. That error signal is applied to a power control to control all heaters in the zone, proportionally varying the input to the heaters until a balanced heat loss condition is realized.

Abstract: An integrated-circuit thermocouple signal conditioner having on a single chip an amplifier and a transistor circuit responsive to the chip temperature for developing a cold-junction compensation signal referred to 0.degree. Celsius. The amplifier includes two matched differential input amplifiers the outputs of which are summed and used to control a high-gain main amplifier. Thermocouple signals are applied to one of the input amplifiers, serving as a floating input stage, and the main amplifier output is connected through a feedback network to the input of the other differential amplifier. A cold junction compensation signal also is applied to the input of the other differential amplifier. The compensation is a differential voltage proportional to the Celsius temperature of the chip; the compensation voltage comprises two components having positive and negative temperature coefficients.

Abstract: A fire sensor discriminates between fires and the flash caused by a projectile piercing the wall of a protected area. The sensor system comprises first and second radiant energy detectors, each sensitive to radiation within different spectral bands. Each detector is coupled to a control signal means for generating a control signal when the radiation sensed exceeds a predetermined amplitude. A third control signal means is responsive to the first and second detectors, and is operative to generate a third control signal whenever the ratio of the amplitude of the energy sensed by the first detector to the amplitude of the energy sensed by the second detector is less than a predetermined value; not generate the third control signal whenever the ratio of amplitude exceeds the predetermined value; and delay generation of the third control signal for a predetermined period of time after the ratio of amplitudes falls below the predetermined value.

Abstract: This invention provides a method and apparatus for early detection of wiping contact between a rotating shaft and bearing metal in a flow lubricated bearing. In one form of the invention, a temperature sensor is provided to monitor bearing temperature at a location on the bearing in proximity to the maximum loading position. The sensor signal is sampled periodically by a plurality of sample and hold circuits so that present and immediately past values of the bearing temperature are always on hand. The sampled values are applied to a set of subtracters, each one of which provides a signal representing the difference between two consecutively sampled temperature values. Selected ones of the temperature differences are applied to summers and the largest sum is selected by a high-value selector and compared with a preselected setpoint value representing an excessive temperature change for a given time period.

Abstract: An alarm system which includes at least one primary detecting device that provides an analog output signal. The rate of change of the analog output signal is monitored, and an alarm signal is generated when the rate of change exceeds a preset limit. The analog output signal is also compared with a first reference level signal to provide a pre-maintenance warning signal when the analog output signal reaches the first reference level.

Abstract: In an array of coke ovens each including a plurality of combustion chambers having a plurality of flue nozzles, a measuring car equipped with a temperature measuring member runs above the array in a direction of the array or in a longitudinal direction of the combustion chambers so as to detect thermal radiations passing through the flue nozzles to measure combustion chamber temperature. The measured temperature is sent to a remote control room through antennae. Where a coal charging car of a Rahmen construction is used an antenna is also provided for the coal charging car so that even when the measuring car runs beneath the coal charging car, radio communication can be assured. The temperature of the combustion chambers can be readily and accurately measured by linearly running the measuring car whether combustion is effected in one or the other side of the combustion chambers.

Abstract: A power control system for a heating element in a cooking appliance having a plurality of possible power settings which provides transient Fast-Heat and Fast-Cool operating modes initiated in response to user-initiated changes to higher or lower appliance power settings, respectively, to reduce the response required for the heating element temperature to reach the operating temperature associated with the new power setting. Approximate heating element temperature information is provided to the control system by an energy counter which is incremented at a rate which is approximately proportional to the rate of increase of the heating element when energized at the power level being implemented. This information is used to prevent initiation of a transient mode if the temperature of the element when the change in setting is made is such that operation in that mode is likely to overshoot the desired new operating temperature.

Abstract: A thermostat monitoring and controlling the temperature of produce ripening within an enclosure and featuring a bridge circuit sensing errors between the actual and desired temperatures in which the desired temperature is selected directly in units of degrees. A bridge amplifier having feedback maintains the bridge in electrical balance to avoid errors due to changes in bridge component self heating. An error detection circuit having a single control simultaneously selects upper and lower error limits centered on the desired temperature, in units of degrees. The circuit indicates whenever the actual temperature goes outside these limits. An alarm circuit indicates a temperature error or a power failure in the thermostat at the thermostat and at a remote location. This circuit utilizes an alternating current source which activates current direction-dependent indicators operating on alternate half cycles.

Abstract: By the employment of the heat-sensitive thyristor, the conventional rate-of-rise action fire detector having a diaphragm deformable by thermally expanding air in a restrictively vented air chamber is easily converted to a combination type fire detector with minimal redesigning or additional fabrication and with an efficient mounting of the thyristor on a metal casing defining the air chamber.

Abstract: An energy-saving electronic thermostat operates by means of a single temperature probe. The rapid decrease in temperature of the probe when a window is opened causes the heating to be switched off or reduced by means of a comparator circuit combined with a network having a large time-constant. The device is employed in a fixed or mobile electric heating convector.

Abstract: A temperature detecting apparatus having a first transistor connected in diode configuration or a first diode, with its forward current set in certain value. A second transistor has similar electrical characteristics as the first transistor or the first diode, with the anode or cathode of the first transistor or the first diode being connected to the base of the second transistor. The temperature difference between the first transistor or the first diode and the second transistor is detected by means of the variation of the collector current of the second transistor. In another embodiment, a third transistor matched to second one is used with common base connections. The first transistor is coupled to the common base coupling.

Abstract: A thermal detection and alarm system for indicating the irradiation of a surface by a heat source such as a laser beam has been invented. The detector element may form an integral portion of the vehicle's outer surface or may be parasitically mounted thereto. The proposed system is light weight, energy efficient, durable and highly sensitive. The invention is especially suited for use with Boron-Tungsten composite surfaces as found on aircraft and spacecraft.

Abstract: The invention provides a fire detection system which comprises an electric thermal transducer such as a thermistor placed in a turbulent gas stream. The transducer produces a signal, having an AC and a DC component, which signal is preferably amplified. The components are separated out in a discriminator, for instance an AC amplifier and the AC component is squared and integrated to give a final output which is proportional to the temperature of a heat source, such as a fire, upstream of the transducer. The invention also provides a fire detection system comprising a series of transducers connected to a single processing apparatus, the signal from the transducers being compared to locate a heat source. The invention also provides a method of detecting a fire using a system as described above.

Abstract: A system for detecting fires in a barn or similar structure includes rate of rise heat detectors and temperature sensing cable. Upon detection of a predetermined rate of rise or a predetermined temperature the control circuitry of the system produces an output signal that activates an audible alarm mounted outside the barn. The control circuitry also produces an FM signal that travels through the power lines servicing the farm. The FM signal activates an audible alarm plugged into an electrical outlet in the home.

Abstract: A digital alarm system for monitoring a variable process signal utilizing a variable, digitally controlled alarm hysteresis capability. The system includes a means for establishing a preselected count level at which an alarm condition occurs. The preselected count level may be established in a high alarm or a low alarm state depending upon the process signal being monitored. Digital signals representative of the process variable are compared with the preset count level signals and upon a coincidence, an output signal is generated to provide alarm signals and also to reset the preselected count level signal to a second preselected count at a level which is a wide variation from the original preselected level so a relatively large change in the process signal occurs before the system is reset to its original alarm condition.

Abstract: A thermostat monitoring and controlling the temperature of produce ripening within an enclosure and featuring a bridge circuit sensing errors between the actual and desired temperatures in which the desired temperature is selected directly in units of degrees. A bridge amplifier having feedback maintains the bridge in electrical balance to avoid errors due to changes in bridge component self heating. An error detection circuit having a single control simultaneously selects upper and lower error limits centered on the desired temperature, in units of degrees. The circuit indicates whenever the actual temperature goes outside these limits. An alarm circuit indicates a temperature error or a power failure in the thermostat at the thermostat and at a remote location. This circuit utilizes an alternating current source which activates current direction-dependent indicators operating on alternate half cycles.

Abstract: A fire detection apparatus in a rotary regenerative air preheater comprises a plurality of temperature sensitive detectors which produce an electrical signal, and means for differentiating the electrical signals from the detectors. The differentiated signals are passed through a low pass filter having a large time constant and are then fed to a comparator which actuates a signalling device when the low pass filter output signal exceeds a predetermined value.