Abstract: The positive temperature coefficient thermistor heater is composed of a positive temperature coefficient thermistor element, and electrodes formed on the both principal faces of the thermistor element. At least one of the electrodes consists of split electrodes. The positive temperature coefficient thermistor heater device has a positive temperature coefficient thermistor heater in which at least one of the electrodes consists of split electrodes, and radiator plates disposed on the both principal faces of the thermistor element. The split electrodes of the positive temperature coefficient thermistor heater are equal in area to each other, or different from each other.

Abstract: Use of PTC circuit protection devices in motor vehicle wiring systems. The devices can replace some or all of the fuses conventionally used. Preferred devices contain PTC conductive polymers. Because the PTC devices can be reset without physical access to them, the wiring system can be arranged more efficiently and more economically. For example, the size of at least some of the wires of the harness can in many cases be reduced.

Abstract: A device and a method for compensating for temperature fluctuations for maintaining the warmth of a cooker having an inverter circuit, which has a system controller which obtains a final compensation data by processing a temperature compensation data outputted from a compensation temperature selection section and a present temperature detected by a temperature detecting section. The system controller outputs a driving signal to drive a bottom heater, a top heater, and a side heater of the cooker according to a calculated final compensation data.

Abstract: A temperature regulating control system for an oven of a cooking apparatus and methods of making and operating the same are provided, the system having a circuit for interconnecting a power source to a load of the apparatus in a regulated manner so as to tend to provide a selected temperature output of the load for the oven, the circuit comprising a microcomputer, external components, and a voltage regulator for providing a regulated voltage from the power source for operating the microcomputer so that the microcomputer can operate the external components, the circuit having a temperature sensing unit to sense the ambient temperature of a portion of the circuit and provide a warning signal to the microcomputer that a first high ambient temperature has been sensed so that the microcomputer can shut down the external components of the system in a controlled manner before a second higher ambient temperature is sensed by the temperature sensing unit.

Abstract: A temperature control method in a rapid heat treatment apparatus comprising simulatively heating dummy wafers in a process tube and previously detecting and grasping by temperature sensors a wafer temperature rising pattern, a heater temperature rising pattern and an internal atmosphere temperature rising pattern, arranging wafers to be processed in the process tube, detecting a temperature of each zone and that of each heater element by the temperature sensors, upon heating the wafers, and controlling each heater element on the basis of the detected temperatures and the wafer, heater and internal atmosphere temperature rising patterns by a controller to rapidly and uniformly raise the temperature of each wafer until the temperature of the wafers in each zone reaches the intended one and becomes stable.

Abstract: A single phase and three phase heater element circuit for a ceramic fiber heater wherein a plurality of blocks each of which is formed by a plurality of heater elements arranged side by side on a base of insulation material and connected to one another to form a series circuit, said series circuit being connected across an electric power source, and adjacent ends of the series circuits in adjacent blocks being connected to the same terminal of said electric power source. By connecting adjacent ends of adjacent blocks of ceramic fiber heater element circuits together, the ends of the series circuit connected to separate terminals of the power source are spaced sufficiently far apart from each other such that current flow through the insulation material between ends adjacent the blocks is minimized and preferably substantially prevented for preventing short circuiting and failure of the heater.

Abstract: An injection molding heater system for heating molding resins or plastics includes a plurality of heaters for heating resin wherein each of the heaters is positioned adjacent a nozzle or manifold. The system also includes an electrical circuit which is connected with the heaters and carries electricity from a power source to each of the heaters in order to energize the heaters. A plurality of circuit breaking devices are incorporated in the circuit for discontinuing the flow of electricity through each of the electrical circuits for preventing circuit damage in case of overcurrent, surges or the like. At least one circuit breaker is positioned in each of the electrical circuits between the power source and each of the heaters.

Abstract: The present invention relates to a system for centralized controlling of a plurality of temperature regulating devices by an existing network of power lines comprising a central control means provided to send or receive predetermined commands to and from a plurality of temperature regulating devices. Each of those devices comprises a communication means adapted to provide two way communication with the central control means, a microprocessor means adapted to store predetermined information received from the central control means, a temperature sensor means adapted to send signals to the microprocessor means and an output means adapted to supply power to temperature varying units. The system further includes a network protecting means adapted to regulate the supply of power to output supply means during sudden change in power supply or due to changes in temperature conditions and a locking means adapted to prevent an unauthorized entry to change temperature condition.

Abstract: A method and apparatus for programmably controlling a cooking appliance. In addition to PREHEAT, COOK, and HOLD modes, the control is operable in a PROGRAM, SPECIAL PROGRAM and TEST mode. In PROGRAM mode a user sets parameters for a plurality of products. In SPECIAL PROGRAM mode global or system oriented settings are made. In TEST mode, individual components may be tested under operation of a control panel. Data may be logged to record usage for individual components and system information. A door sensor override may be used to turn OFF desired components when a door is open. A vent may be opened to reduce humidity at various programmed times during a COOK cycle or based on sensed parameters (e.g. humidity in the cooking chamber. A speaker may provide alarms that are programmable in volume and frequency for different products or events. Restricted access to different program or test modes is disclosed.

Abstract: An electronic system for diverting current to a high-current load on an automobile, such as an electrically heated catalyst, is disclosed. In the system, the current of the high-current load is switched by electronic circuitry, rather than by an electromechanical relay. When current is no longer required by the high-current load, the electronic system allows current to flow to other loads on the automobile. The electronic system avoids the disadvantages presented by a relay's abrupt switching of the high currents involved.

Abstract: Compressed air-driven electrical generator supplies electric current to resistance heating element on demand in a baseboard heating system. A thermostat in communication with an air valve actuator, allows compressed air to flow from an air holding tank to an air motor which drives the electric generator whenever the temperature in the control space drops below a pre-selected temperature. An electrical relay switch in series with the electric generator and an electrical resistance heating element opens the electrical circuit between the electric generator and the heating element whenever the temperature sensed by the thermostat drops below the pre-selected temperature.

Abstract: A temperature regulating control system for an oven of a cooking apparatus and methods of making and operating the same are provided, the system having a circuit for interconnecting a power source to a load of the apparatus in a regulated manner so as to tend to provide a selected temperature output of the load for the oven, the circuit comprising a microcomputer, external components, and a voltage regulator for providing a regulated voltage from the power source for operating the microcomputer so that the microcomputer can operate the external components, the circuit having a temperature sensing unit to sense the ambient temperature of a portion of the circuit and provide a warning signal to the microcomputer that a first high ambient temperature has been sensed so that the microcomputer can shut down the external components of the system in a controlled manner before a second higher ambient temperature is sensed by the temperature sensing unit.

Abstract: A heater for heating fluid is shown having a plurality of self-regulating electrical resistance heater elements 22 placed in electrically and thermally conductive relationship with heat transfer members 20, 120. The heat transfer members are each configured to form a plurality of fluid receiving channels so that when placed in a fluid stream heat generated by the heater elements will be dissipated to the fluid through the heat transfer members. Additionally, thermally conductive grease is used between the heater elements 22 and heat transfer member 20, 120 to better transfer the heat. The heater elements are arranged in groups with at least two heater elements in a group electrically connected in series and the groups electrically connected in parallel.

Abstract: A heat treatment system is fabricated from a loading section, a heat treatment section and a outlet section integrated with one another, and the heat treatment section comprises a transfer mechanism provided between the loading section and the outlet section for successively transferring silicon wafers, a heating unit provided along the transfer mechanism for heating the silicon wafers, and a cooling unit provided along the transfer mechanism and closer to the outlet section than the heating section for cooling the silicon wafers so that the silicon wafers are continuously treated with heat for annihilating thermal donors produced from oxygen during the growth of a silicon crystal without any handling by operators.

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 heater for the rapid heating of water includes a main body having plural vertical upwardly opening chambers, combined with a molded cover plate that can be removably installed over the upper part of the main body. A plurality of combination heating and chamber partition assemblies extend downwardly from the bottom surface of the installed cover plate and one each of the assemblies resides in a main body chamber, each assembly including a generally flat and vertically elongated partition member and a pair of heating coils mounted to each partition member, one each coil on opposite sides of the partition member, and each partition member cooperates with a chamber to form a first channel for conducting water downwardly and a second channel for conducting water upwardly.

Abstract: An electric circuit is disclosed which includes a heater element for generating heat, a power switch for controlling the current to the heater element, a night light for providing illumination, and a night light switch for controlling the current through the night light. The night light is operable separately and independently of the heater element. In one embodiment for use in a humidifier the electric circuit further includes a thermo fuse, a thermo disc and a refill light. In another embodiment for use in a heater the circuit further includes a fan, a power light and a second heater element for generating heat.

Abstract: A heat generator is formed to quickly raise the temperature of an object to be heated to a target level and then maintain the temperature of the object at the target level. The heat generator includes a high output heating element for heating the object to be heated, a temperature controller which is thermally coupled with the object and connected in series with the high output heating element for deenergizing the high output heating element when the temperature of the object exceeds the target level while energizing the high output heating element when the temperature of the object is reduced from the target level by a prescribed value, and a positive temperature coefficient thermistor which is thermally coupled with the object and connected in parallel with the high output heating element and the temperature controller, the thermistor having a Curie point set so as to produce an output capable of maintaining the object at the target temperature even when the high output heating element is deenergized.

Abstract: A continuous flow water heater assembly requiring no storage tank and including an entrance chamber having a flow control switch mounted therein adapted to be activated upon a positive flow of water through the system wherein the water flows from the entrance chamber to a plurality of heating elements each of which are at least partially segregated by virtue of their being removably mounted within separate heating chambers. The heating chambers are attached in fluid communication to one another by a plurality, at least two, ports which are of proportionately different sizes such that water will be passed between the first and second heating chambers in proportionately different amounts through the different sized ports. Water is thereby effectively distributed between the heating elements so as to prevent exposure of the heating elements when activated and thereby eliminating either of the heating elements from being exposed to air and thereby subject to burnout.

Abstract: The present invention is a cooking appliance or an electronic control for a cooking appliance and method of controlling the same. A remote control unit having a built-in temperature sensor, positional switch and low-battery detection circuit is in two-way intermittent wireless communication with the appliance control unit of the present invention. The appliance control unit includes a switch means for controlling the heating elements of the cooking appliance wherein the switch means for each heating element includes two power switches connected in series and coupled with a redundancy detection circuit for the detection of a failure of one of the two power switches. Two-way communication between the two control units of the present invention is constantly monitored to ensure proper operation of the cooking appliance and to provide a mechanism to report errors to the user or to shut down the cooking appliance, as appropriate, soon after an error is detected.

Abstract: Electrothermal conversion elements, apparatus and methods for use in comparing, calibrating and measuring electrical signals. The element emits IR radiation in response to electrical input. The radiation is collected and converted to an electrical signal proportional to the RMS value of the input signal. Isothermal operation enhances both IR and electrical operation.

Abstract: A control system for a beverage brewing apparatus which includes a programmable control module and a separate input device. The control system is used with a beverage brewing apparatus of the type having an infusion assembly for retaining and filtering a brewing substance, a heated water source and a water distribution system for transporting water from the heated water source to the infusion assembly. The programmable control module controls numerous adjustable functions associated with the brewer and stores at least one function limit for each of the functions which it controls. The separate input device is selectively attachable to the control module for manipulating the function limits of the programmable function retained and controlled by the control module. Function controls are associated with the input device for selecting a function to manipulate and for incrementing and decrementing the limit or limits of the selected function.

Abstract: An electrode boiler comprising a container for containing water and electrodes within the container which serve to pass electrical current through such water and which are generally upright when the boiler is in use. Fill and drain valves are connected to the container to enable water to be fed to and drained from the container. An outlet of the container enables steam generated inside the container to pass out therefrom when the boiler is in use. A water level contact member is arranged to cause a signal to occur when the water in the container reaches a predetermined level. The boiler is provided with a store to store the value of an allowed time for water to boil away from the said predetermined level until the water is no longer in contact with the contact member. A timer is connected to time the actual time it takes for such boiling away to occur, and comparator is connected to the store and the timer to effect a comparison between the allowed time and the said actual time.

Abstract: Apparatus for producing a non-uniform temperature profile in a short duration wind tunnel includes a plurality of nested cylindrical elements each having an inlet end and an outlet end, a plurality of heater element extending axially along the surface of each of the cylindrical elements. The length and thermal mass of the cylindrical elements permits the temperature of test gasses to be raised to the desired level while the gasses are passing over those elements. A plurality of honeycomb elements occupy the space between each of the cylindrical elements to distribute the heating effects smoothly both radially and circumferentially. Each heater is controlled individually by a control circuit in order to establish the desired temperature profile at the outlet end of the apparatus.

Abstract: Plural electrical loads supplied with power from a single source are monitored to detect defective loads. Each load is periodically individually energized and current delivered by the source is measured. Measured current for each load is compared with limit values to detect abnormal values. To overcome consequences of supply voltage fluctuations, supply voltage is also measured and admittance of each load is determined from measured current and measured voltage. The admittance value thus determined for each load is compared with limit values to detect abnormal values. Load monitoring of loads energized according to a control algorithm proceeds by periodic momentary suspension of energization according to the control algorithm and energization of selected individual loads.

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 method and apparatus is disclosed which automatically adjusts the on-time of preferably quartz lamp heating elements in an oven having both quartz lamp and electric heating elements. In such an oven having dual heating elements, the temperature of the oven's cavity increases when numerous food items (loads) are rapidly cooked in succession. The present invention allows a dual heating element oven to automatically compensate for these increases in temperature by preferably shortening a predetermined on-time of the quartz bulbs. The on-time is continuously compensated using a microcomputer, dependent upon the current oven temperature. The microcomputer preferably uses at least two clocks to shorten the predetermined on-time of the quartz bulbs.

Abstract: A control system for dual oven resistance heaters (BAKE, BROIL) has opposite sides of each heater connected to a common side of one of a pair of SPDT switching relays such that no current flows to the heaters when both relays are in a common state of energization/de-energization. A microcomputer receives a signal from the oven temperature sensing and signals separate switching devices to selectively energize/de-energize one of the relays to switch on the desired heater. Separate comparators also receive the temperature sensor signal; and, in the event of failure of the microcomputer or switching devices with a heater "ON", the comparator is operative to bring the relays to a common state, preventing current flow to either heater.

Abstract: A method and apparatus is disclosed for automatically preheating an oven, such as a food oven, based upon its immediate usage history. This preheat function operates by regulating the base heating elements until the temperature of the base plate is within a specified temperature range from the pre-programmed base set point temperature, and then turning quartz lamps on until the air temperature within the oven cavity reaches a certain fixed preheat "exit" temperature. This preheat exit temperature need not be a fixed value, but can be a function of the base set point temperature or the air temperature before or during the preheat operation. In addition, the preheat function can be performed at various times during the oven's operation, and not necessarily only upon power up of the oven.

Abstract: An electrically operable heating system which comprises a plurality of heating units has one or more control units for controlling the operation of each heating unit. Each control unit operates on the basis of two input signals (F) and (P). One (F) represents the maximum proportion of the power of the associated heating unit or units which can be made available at any time and the other (P) represents the fraction of that proportion required at a particular time. Also disclosed is a system in the switching of heater units is carried out in a random manner.

Abstract: A heat/process control is disclosed which takes advantage of the characteristics of some plastics in that they absorb medium wavelength infra-red heat waves in a comparatively wide range of temperatures (and therefore wavelengths). The heaters used in this equipment are of quartz-tube construction which can be used through a wide temperature range. Tests have indicated that lamp wattage and machine processing speed were mathmatically related. For plastics of different formulation and/or thickness a series of parametric curves exist. Each curve is resident in the machine control and can be incorporated with a simple selector switch. For a given plastic a mathmatical equation relating speed and heater temperature is selected. If an increase in speed is required, the target speed and associated temperature is calculated and then loaded into the controller.

Abstract: An apparatus which provides selectively either constant power, constant current or constant voltage to the heating elements of the thermods. The soldering system power supply apparatus includes devices for monitoring and controlling individual temperature profiles of each soldering thermod heating element. A computerized arrangement controls the power to each thermod in a very accurate manner. For the purpose of adjusting the power to each thermod element as a function of its temperature and the desired temperature profile, a set of temperature sensors are coupled to each of the thermod elements for measuring its temperature. Similarly, a set of energy sensors are also coupled to each of the thermod elements for detecting the amount of electrical energy supplied to each thermod.

Abstract: A stove for burning in electronic modules which incorporate a heatsink to radiate heat comprises for each module controlled electrical power supply circuits and locally controlled temperature regulators employing a controllable dissipator comprising a heat shunt. The heat shunt comprises a heat conducting body, an arrangement for placing the heat conducting body in contact with the heatsink of the module so that they cooperate thermally as a result of the resulting conduction of heat by contact, an arrangement for heating the heat conducting body and a heatsink adapted to dissipate heat from the heat conducting body to an external environment. The dimensions and the geometry of the heatsink of the shunt and the temperature and ventilation conditions of the external environment are adapted to enable a quantity of heat to be extracted from the shunt by its heatsink which is greater than the quantity of heat dissipated by the heatsink of the module.

Abstract: A control system for regulating electrical power input to the resistive heating elements of an electric heating apparatus, including domestic cooking appliances, is provided which employs at least one piezoceramic relay device. The electrical power is applied with the piezoceramic relay device responsive to control signals and with the control circuitry being directly and ohmically connected to the power source. In one embodiment, the control system employs individual piezoceramic relay devices for power regulation to the individual heating elements while in different embodiments a single piezoceramic relay device regulates power input to a pair of the heating elements. A method of operating the controlled apparatus in such manner and an apparatus having such control system are also disclosed.

Abstract: A control system, a control device therefor and methods of making the same are provided, the control system comprising a source of energy, an output producing unit that uses the energy to produce the output thereof, a control device having control structure for interconnecting the source of energy to the unit, the control device having a rotatable shaft that sets the control structure in different positions thereof in relation to the rotational set position of the shaft from an "off" position thereof, the control structure having the amount of the energy passing therethrough from the source to the unit being different for each set position thereof, indicating structure operatively associated with the shaft for visually indicating the set position of the shaft and, thus, the amount of energy being fed by the control structure to the unit, and sensing structure operatively associated with the shaft that senses the set position of the shaft and electronically displays that sensed position of the shaft whereby th

Abstract: A fail-safe control system for operating a power relay to energize an electrical load such as a resistive heating element in a cooking apparatus includes first and second driving transistors connected in series with the control winding of the power relay and a source of power. A logic circuit, such as a microcomputer, produces pulses having specified characteristics at a single output port in order to energize the control winding. A circuit interconnecting the output port of the logic circuit with the driving transistors includes a first branch connected with the first transistor and a second branch connected with the second transistor. The first branch of the circuit includes an operational amplifier connected by a capacitor with the logic circuit output port in a manner that the first branch will drive the first transistor for a sufficiently long period of time initially in order to energize the relay control winding and cause the power relay to pull in.

Abstract: A multiplex heating system for measuring and regulating the temperature of a plurality of heating elements is disclosed. The heating system includes a plurality of heating elements, which also function as temperature sensing elements, that exhibit a known change in resistance as a function of temperature. The heating system further includes a power source, a control apparatus for regulating the respective heating power of each heating element, a measurement apparatus for measuring changes in resistance in the heating elements, and a plurality of switching arrangements. Each switching arrangement is coupled between one of the heating elements and, alternately, the control apparatus and the measurement apparatus, connecting the heating element to either the control apparatus or the measurement apparatus.

Abstract: A microcomputer-based, closed-loop electronic temperature control system and method for an electrically heated cold weather garment having a plurality of independently heated zones. In one preferred embodiment the system comprises a potentiometer for selecting the desired temperature at which a plurality of areas of the garment are to be maintained, a thermistor for determining a reference temperature of the interior areas of the garment, and a plurality of conductive heating wires operable to heat each area of the garment independently. The system further includes a plurality of solid-state semiconductor power devices for controllably allowing current flow through each heating wire and, a plurality of current sensing circuits for sensing the current flow through each heating wire. The microcomputer receives information from the potentiometer, the thermistor and the current sensing circuits, and determines therefrom the level of heating required for each zone.

Abstract: A bushing balance controller controls the overall average temperature of a multiple segment glass fiber forming bushing and the temperature of each individual bushing segment. Current shunting loops divert current away from each bushing segment as required to provide the proper bushing segment temperature profile as well as the desired average bushing temperature.

Abstract: A process and device for controlling heating of a furnace by means of electrical resistors using switching devices, particularly thyristors, associated with the electrical resistors, and whose operation is to be controlled. The switching devices are controlled in syncopated mode by an industrial computer, a programmable industrial robot or equivalent which performs a set of functions which make it possible to compute the power to be dissipated in the resistors, and control directly the switching devices so as to dissipate the previously coputed power. The invention applies particularly to controlling industrial furnaces and more particularly of glassmaking furnaces, particularly furnaces for heating of glass for the tempering and/or bending of the glass.

Abstract: A temperature control system for use with a fluid circulating system operable in a heating or cooling state to monitor and control the temperature and flow of fluid circulated through a remote liquid circulation manifold comprising a display/control panel to select the system operating parameters and provide a visual indication of the system status including operating temperature and fluid flow and a micro including logic circuitry to receive input signals from the display-control panel and fluid circulating system and to generate system control signals to control the operation of the fluid circulating system and system indicator signals to provide the visual indication of system operations.

Abstract: An apparatus for heat treating the surface of a body includes at least one infrared lamp carried on a stand. A circuit is provided for controlling the energization of the lamp. The circuit includes a parameter input mechanism for permitting an operator to input at least one operating parameter to the circuit. The circuit also includes a proportional control software responsive to a temperature of the body being heat treated and responsive to a parameter inputted by the input mechanism.

Abstract: A power switch (2) of a coffee brewing machine comprises a button (3) for manually switching on and off the brewing machine. The switch (2) further comprises detection means (24) for switching off the brewing machine in case an abnormal situation is detected, for example, when a predetermined period of time has elapsed.

Abstract: A temperature control system incorporating a temperature sensor characterized by thermal inertia which causes the sensed temperature to lag the actual temperature during the transition from one operating temperature for the controlled environment to a different operating temperature. This control system controls temperature as a function of setpoint temperature and the value of a temperature control variable representing the sensed temperature. The value of the temperature control variable is set equal to the temperature sensed by the sensor during steady state operating conditions. In response to a change in setpoint temperature, the system adjusts the value of the temperature control variable to compensate for the thermal lag of the sensor.

Abstract: A hot water heater control device and method for a building such as a home will allow the consumer user maximum savings with a modest investment by allowing the user to program into a control module a particular living cycle and assign a desired temperature to each of a predetermined number of heating start/stop times within the cycle. A means exists for the user to program a desired high, medium, low and off temperature into a control module. Also, any one of several special condition modes may be activated as needed in order to provide maximum flexibility and savings.

Abstract: A hybrid, open-loop electronic temperature control system and method of heating for an electrically heated cold weather garment having a plurality of independent heating zones. In one embodiment the system includes: a plurality of conductive heating wires, with at least one such heating wire being disposed in each zone of the garment and operable to heat each zone of the garment independently; a plurality of solid-state semiconductor power switching devices for controllably allowing current flow through each heating wire; and plurality of power selection circuits, with each having a potentiometer and being associated with each solid-state power switching device, for providing individual power level selection for each heating wire of the garment. This gives the wearer individual control over the temperature level of each zone of the garment.

Abstract: The invention relates to a method of controlling the supply of electric power to an electric sauna heater, the sauna heater being divided into two portions to be heated separately: a stone space (1) and an air duct (2) each being provided with one or more heating elements (1A1-1A3, 1B1-1B3, 2A1-2A3, 2B1-2B3) to heat the heat-storing material placed in the stone space (1) and the air contained in the sauna room, respectively. In the invention, to achieve good operating properties in this kind of sauna heater both with respect to the heating of the stone space and the air space of the sauna room without increasing the rated wattage of the sauna heater to an unreasonably high value, one or some of the heating elements are disconnected or connected to operate at partial power, whereby the power demand of the sauna heater is always smaller than the total power of the heating elements (1A1-1A3, 1B1-1B3, 2A1-2A 3, 2B1-2B3).

Abstract: This power adjustment device for electric power systems, in particular for electric power systems with electric ovens, has the aim of optimizing the electric absorption of the system by reorganizing the power requests of the various users comprised in the system. The device comprises elements for detecting the power requests of a plurality of users, a control and management unit adapted to check if the available power is sufficient to feed the requesting users and to enable and disable selectively some of the users operating at that moment according to the available power and according to criteria of priority or of elapsed operating time.

Abstract: A reflow furnace control system is contemplated to give an optimum time-temperature profile of an object intended to be heated. The object is carried on a conveyor to move along a conveyor path in the reflow furnace during which it is heated by heaters disposed along the conveyor path. A data table is provided to store sets of control data relating to the conveyor speed and the operating temperatures of the individual heaters. Each set of the control data is closely associated with various conditional parameters indicative of configuration and material characteristics of the object and the required temperature to which the object is heated. Control data assigning section is interfaced with the data table so that it responds to the entry of the conditional parameters for retrieving from the data table a relevant control data. Based upon the retrieved control data, the furnace is controlled by the system to give an optimum time-temperature profile of the object.

Abstract: A wafer chuck temperature control system is disclosed for use in a semiconductor wafer testing apparatus. The wafer chuck is divided into a plurality of temperature sensor and cooling element domains corresponding to chip location regions of an overlying undiced wafer being tested. Computer scanning of the sensors determines which domain is the one harboring the heat source (chip under test) and selects the same for connection to a closed loop temperature control feedback servo. Provision also is made for introducing a helium gas interface between the wafer and the chuck by placing annular grooves in the face of the chuck through which the helium flows when the wafer is vacuum-seated against the chuck. A predetermined helium gas flow rate is maintained to preserve vacuum holddown and to optimize the thermal resistance of the wafer-chuck interface.