Abstract: A rotary apparatus in which at least one electrically controlled device is attached to a rotor. The rotor carries coils such that rotation of the rotor generates power for the device. A switch is provided for controlling the supply of power to the device and receives control signals via a contactless communication link.

Abstract: A supplemental controller for a fiber glass bushing actively performs heating and cooling of a connected segment of the bushing which is otherwise controlled by a primary controller. In one embodiment, the supplemental controller performs heating by means of current injection into a connected bushing segment and cooling by means of current diversion from or around the connected bushing segment. Initial start-up and balancing operations can be performed without activation of the supplemental controller. In another embodiment of the invention, the supplemental controller heats a bushing segment by injecting current in-phase with current from the primary bushing controller and cools the bushing segment by injecting current out-of-phase with current from the primary bushing controller.

Abstract: A control system includes a variety of structures including a steam table having a reservoir with heating elements, a water level temperature probe, a safety lower temperature probe, upper overflow probes for use in filling, lower safety probes, and normal water level probes; a thermal cabinet, ice machine and other thermal devices. The controller utilizes at least one of relay shaking, probe movement checking, probe feedback checking, disappearing equipment, water working system, air flow factoring, best verifiable logic, pulse cooling, AC energy sensor analysis, cooling potential sensor analysis and pulse heating to keep the heating elements at a more even temperature during the heating process and reduce extreme thermal cycling. In addition, the system can locate intermittent problems and display the problems to workers or management, or to a central controller to initiate action in advance to repair the problem before it causes a breakdown in the equipment.

Abstract: A method is disclosed for detecting a condition indicative of fire or elevated potential for fire, broadcasting a signal in response to its detection and for operating various controlling devices in response to the broadcast signal in order to enable or disable valves or appliances connected to a power supply through the controllers. Also disclosed is a system having a sensor, a transmitter responsive to the sensor, a receiver for receiving signals from the transmitter and controllers responsive to a signal from the receiver for controlling devices in accordance with the method of the invention. Each of the controllers is shifted from its normal position to a second position upon the receipt of a signal from any one of the sensors, and more than one controller device may be controlled by a given receiver.

Abstract: An open apparatus is described for the processing of planar thin semiconductor substrates, particularly for the processing of solar cells. The apparatus includes a first zone for the drying and burn-out of organic components from solid or liquid based dopant sources pre-applied to the substrates. The zone is isolated from the remaining zones of the apparatus by an isolating section to prevent cross-contamination between burn-out zone and the remaining processing zones. All the zones of the apparatus may be formed from a quartz tube around which heaters are placed for raising the temperature inside the quartz tube. Each zone may be purged with a suitable mixture of gases, e.g. inert gases such as argon, as well as oxygen and nitrogen. The zones may also be provided with gaseous dopants such as POCl.sub.3 and the present invention includes the sequential diffusion of more than one dopant into the substrates. Some of the zones may be used for driving-in the dopants alternatively, for other processes, e.g.

Abstract: A system for and a method of controlling the temperature of an object (22). Temperature sensors (30) are placed on the object (22) in abutting zones (24) substantially covering a surface of the object (22), so as to detect a temperature in each of the respective zones (24). Temperature adjusting elements (28) are spaced from and thermally coupled to the object (22), to adjust the temperatures of corresponding ones of the respective zones (24). Temperature control circuits (32, 34, 36), responsive to temperatures detected by respective ones of the temperature sensors (30), control the corresponding ones of the temperature adjusting elements (28) to maintain the temperatures of the respective zones (24) within a preset temperature range. When the object (22) is in a cold environment and is to be maintained at a warmer temperature, the temperature adjusting elements (28) are heating elements.

Abstract: A temperature control system for electric range surface heating elements including an infinite switch electrically coupled to a surface heating element and a second switch, which selectively couples 120 VAC or 240 VAC power across the infinite switch and heating element. Alternatively, the second switch selectively couples either the infinite switch or an electronic controller to a surface heating element, wherein the electronic controller has timing circuits for cycling power supplied to the surface heating element according to a preset timing scheme within the timing circuits.

Abstract: An air heating and control system, which in one application controls the diameter of a calender roll in the paper making process, includes a row of heater packs proximate to the various zones of the calender roll. Each heater pack has a plurality of electrical heating coils which are at least partially connected in parallel so that failure of one coil does not interrupt power to the remaining coils. Air flowing through the heating coils is heated to a desired temperature and impinges upon the calender roll to expand it as desired. A control system senses a defective coil, which effectively reduces current in a heater pack, and increases the voltage imposed upon that heater pack to again produce the desired power level or heating effect. Thus failure of a heating coil is immediately compensated for.

Abstract: A heating assembly, for use as an electric blanket or personal heating pad, includes a flexible heating panel and an electric circuit for heating the panel. An electrical heating element is mounted directly on the panel and includes inner and outer coaxial coil conductors separated by an electrically insulating layer and surrounded by an outer electrically insulating layer. A two-core flexible electric cable connects the heating element to the power supply, and to an electric control switch for controlling operation of the heating element, a fuse being located in the circuit to be actuated in the event of a short circuit occurring between the conductors of the heating element, due to breakdown of the inner insulating layer. The electric circuit also includes a device for controlling the temperature of the heating element.

Abstract: An electric cooking appliance operable from two 120 VAC household circuits. The electric cooking appliance includes a plurality of surface heating units and a pair of oven heating units operably coupled to two AC power sources. The oven heating units are coupled to one of the power sources through a thermostat and a switching circuit for alternately switching the heating units between a high bake, a high broil, and a dual bake/broil setting. A plurality of surface unit switches interposed between the power source and each surface unit controls the operation and current draw of the each surface unit.

Abstract: A system for and method of controlling the temperature of a flat workpiece such as a semiconductor wafer are disclosed. The workpiece is mounted on a workpiece chuck which is mounted over a base between the chuck and a host machine such as a wafer prober used to test integrated circuits on a wafer. The chuck includes an upper portion on which the workpiece is mounted. The temperature of the upper portion of the chuck is controlled to control the temperature of the workpiece. The temperature of the base is controlled to reduce the amount of heat flow between the chuck and the host machine. A power and control system includes a switching power supply which provides power to system components including heaters in the chuck used to heat the workpiece. A series of filters removes electrical noise generated by the switching power supply such that low-noise operation is realized.

Abstract: An electrically powered water heater includes a plurality of heating elements for substantially instantaneous heating of fluid passing through the heater. A controller for powering the plurality of heating elements is responsive to a temperature sensor in fluid communication with the heated fluid. The temperature sensor activates each of the plurality of heating elements for a predetermined period of time that is preferably no more than 32 half cycles. The controller activates a second heating element after a delay of preferably no more than 8 half cycles after activating a first heating element. The predetermined period of time for activating each of the plurality of heating elements may be substantially equal, such that each heating element contributes substantially equally to the heating of fluid. In one embodiment, the heater housing is provided with a plurality of chambers, and a heating element is provided within each of the plurality of chambers.

Abstract: A heating system and method used to maintain a fluid flowing through a component (such as a mass flow controller) within approximately a predetermined temperature range. The fluid flows through a cavity in the component. A heater element and a sensor are positioned within the body of the component and the heater element is coupled to a power source. The temperature sensor is electrically connected to a controller. The controller will receive an input indicative of the temperature, determine whether the input falls within a predetermined temperature range, and output a signal to the power source to adjust the power provided to the heater element as necessary in order to maintain the temperature within the predetermined temperature range.

Abstract: A substrate processing apparatus reduces an instantaneous maximum power consumption at turn-on. Power receiving parts of a plurality of processing units are connected to one end of a turn-on switch respectively through switches. The other end of the turn-on switch is connected to an external power source through a breaker. Timer values are set in advance in the timers, respectively. When the turn-on switch is turned on, the timers turn on the associated switches respectively after times which are defined by the timer values, whereby the processing units are provided with electric power, each with a delay of a constant time.

Abstract: A fryer system having a vat containing shortening, a first heater for supplying heat to the shortening, and a second heater for supplying heat to the shortening. The second heater is preferably activated only when the temperature of the shortening falls below a predetermined minimum temperature and disabled when the temperature of the shortening reaches a predetermined maximum temperature. In one preferred embodiment, the first heater is a heat exchanger with a gas burner while the second heater is an electric heating element. In another preferred embodiment, the first heater is an electric heating element and the second heater is an autotransformer supplying an overvoltage to the electric heating element. A method for operating a heating system for a fryer is also disclosed.

Abstract: A substrate heating apparatus having a chamber, a device for adding gas into the chamber and a substrate heater is provided. The substrate heater is located within the chamber and includes a first plate having a bottom surface. The bottom surface of the first plate has at least one groove. The at least one groove forms at least two thermal zones on the first plate. The substrate heater further includes a heater element and a second plate. The heater element is located between the bottom surface of the first plate and the second plate and thus enables heating of the substrate by radiation and gas conduction.

Abstract: An image recording apparatus includes a discharge head and a discharge control device. The discharge head includes an ink chamber with a discharge hole, a first heater for heating and gasifying ink, a shutter unit, provided at the discharge hole portion, controlled to discharge gasified ink intermittently according to an electrical signal corresponding to image data to be recorded, and a first member for maintaining the temperature of the discharge hole sufficiently lower than the temperature of the first heater in operation of the first heater before initiation and after completion of image data recording. The discharge control device controls the shutter unit.

Abstract: A novel controller in an electrical smoking system and method, wherein the method includes the steps of: establishing a preferred thermal pathway to be executed with each heater activation responsively to a puff on an electrically heated cigarette; configuring a power cycle in accordance with the desired thermal pathway; dividing the power cycle into at least first and second phases each having a respective, predetermined time period and total energy input for each phase; and adjusting a respective duty cycle (or other power-adjusting factor) in each phase of the power cycle responsively to a voltage reading of the power source such that the established, respective total energy input of each phase is achieved during the time period of each power cycle.

Abstract: The invention is directed to an electric circuit configuration (1) for an electrical load, in particular for an electric hair dryer, a fan heater or the like. The circuit configuration (1) comprises two heating resistors (2, 6) in parallel arrangement, of which the second heating resistor (6) is equipped with a serial switch (5). The two heating resistors (2, 6) may be connected to an a.c. source. Furthermore, provision is made for a d.c. fan motor (11) connected to one of the two heating resistors (2) via a rectifier circuit (7). The rectifier circuit (7) includes two rectifiers (8, 9) in antiparallel arrangement having connected to their junction (10) one of the connecting points of the d.c. fan motor (11). The other connecting point of the d.c. fan motor (11) is connected to the second heating resistor (6) which is equipped with the serial switch (5).

Abstract: A method and apparatus are provided for controlling parallel heater elements, the method including the steps of: providing a plurality of electrical heater elements; generating a plurality of temperature signals associated with a plurality of the heater elements; generating a control signal based on one or more temperature signals; providing an alternating current power supply connected to the electrical heater elements through a power transmission system; generating a signal when the voltage of the alternating current power supply passes through ground potential; blocking electrical power to a heater element starting when a zero detection signal is detected an ending when another zero detection signal is detected, for a fraction of the alternating current cycles in a time period, the fraction being a function of the control signal; and transmitting temperature control signals through the power transmission system.

Abstract: A radiant electric heater has first, second and third heating zones (1, 2, 3) arranged substantially side-by-side. The first heating zone (1) is provided with at least one first heating element (9). The second heating zone (2) is arranged adjacent to the first heating zone and is provided with at least one second heating element (10). The third heating zone (3) is arranged adjacent to the second heating zone and is provided with at least one third and one fourth heating element (11, 12). A switch (15) is provided for switching between first, second and third heating states. In the first heating state the at least one first heating element (9) of the first heating zone (1) is energised alone, the at least one second, third and fourth heating elements (10, 11, 12) of the second and third heating zones (2, 3) being de-energised.

Abstract: A cooking oven comprises convection and microwave heat sources (not shown), controls 1 and 3,4 for presetting the temperature and cook time of the oven for a food item to he cooked therein, a further control 5 for selecting a reduced time cooking routine for the oven, and a microprocessor (not shown) responsive to the operation of the further control 5 for controlling the convection heat source and/or the microwave heat source in accordance with a reduced time cooking routine which is determined by the preset temperature and cook time (FIG. 1).

Abstract: A thermally insulated substrate, e.g. a system of pipes, is maintained above a selected minimum temperature by means of one or more electrical heaters, preferably elongate self-regulating heaters. Each heater is successively switched on for a heat-up period and then off for a cool-down period. The durations of these periods are successively determined by reference to the ambient air temperature adjacent the substrate at an earlier time, e.g. at the end of the previous cool-down period. The method is particularly useful for temperature-maintenance systems in which a number of heaters are used to heat a complex system of pipes. The durations of the heat-up and cool-down periods for each heater (or for a group of two or more heaters) are separately determined by means of a single microprocessor.

Abstract: A control device installed in an electric water heater to control its operation, the control device including a water temperature control circuit and a power control circuit, the water temperature control circuit being formed of a water temperature detection circuit, which detects water temperature at the water inlet and the water outlet of the electric water heater, a water flow rate detection circuit, which detects the flow rate of water passing through the water inlet, a CPU, an indicator circuit controlled by the CPU to indicate the working conditions of the electric water heater, and a digital display controlled by the CPU to show the value of water temperature at the water outlet, the power control circuit being formed of a power supply circuit, a TRAIC triggering control circuit, which turns on the heating elements of the electric water heater alternatively subject AC phase change, a TRAIC power circuit, which provides the TRAIC triggering control circuit with the base power, an AC phase detection inpu

Abstract: Apparatus for processing a silicon workpiece uses reflected UV light to measure and control the workpiece temperature. A linearly polarized beam including UV light is directed onto a silicon surface to produce a reflected beam. The reflected beam is cross-polarized to null out much of the light, and the resulting residual reflectivity spectrum is determined. The temperature is determined from the characteristics of this spectrum. A workpiece heating station uses this measuring technique to accurately control the temperature of a silicon workpiece and temperature-dependent processing over a wide range of processing temperatures, including temperatures below 500.degree. C.

Abstract: A vertically oriented thermal processor supporting semiconductor wafers within a vertical processing chamber within a process tube about which a furnace heater is supported utilizes a model-base control target in combination with a heating control system configured to heat portions of the furnace in order to achieve a thermally uniform processing chamber environment. A furnace power controller implements a dynamic control system configured to achieve a desired uniform thermal distribution within the processing chamber during various processing cycles for semiconductor wafers. Preferably, the control system monitors thermal conditions within the chamber and compares the conditions with a desired thermal model of the furnace, and activates/deactivates one or more heater elements within the furnace in order to achieve a desired thermal condition within the processing chamber.

Abstract: A method and apparatus for characterizing and controlling the heat treatment of a metal alloy employing non-contact sensors selectively positioned to minimize the effects of background temperature contributions. The sensors monitor the temperature of the part being treated at a location that is remote from the surface that is being irradiated directly. In preferred embodiments, the surface where the temperature measurements are taken are located within a black body source. The collected temperature information is used to control the heat treatment of the metal alloy.

Abstract: A method and apparatus for efficiently heating for instance a semiconductor wafer or reticle substrate in either vacuum or air, by exposing the wafer or reticle to radiation whose spectrum is such that it includes only wavelengths which have been determined to be efficiently absorbed by the material of the wafer or reticle. This advantageously allows more rapid and uniform heating than is allowed by prior art broadband radiation, convection heating, or conduction. The wavelength and bandwidth of the radiation are selected to be those wavelengths efficiently absorbed by the wafer or reticle, depending on its particular material and thickness. Typical applications are to a wafer or reticle located in a vacuum where convection or conduction heating are inconvenient or absent.

Abstract: A heating panel has a substrate with a resistive heating material disposed thereon. The substrate can be metal with an insulating layer disposed between the substrate and the heating layer. Alternatively, the substrate can be glass ceramic. The heating layer has electrodes on opposite edges connected to different phases of a multiphase power source. Another electrode on the heating layer can be connected to a neutral of the power source. Capacitive currents caused in the substrate or a metal object on the substrate by the different phases cancel each other. Thus, leakage current through a conductor connected between the substrate and ground is minimized. The heating panel can be adapted for two phase or three phase systems. Power to the panels is controlled by solid state switches or relays. Zero crossing drivers sense supply voltages and operate the switches to balance currents in the panels.

Abstract: An apparatus for simultaneously welding multiple molded plastic parts includes a power delivery module, a measuring arrangement, a parameter storage module, a user interface, and a controller, is designed for use with plastic parts that each have at least one fitting with a heating element and an identifying resistor. The power delivery module is designed to supply power to the multiple heating elements and includes a common power supply, multiple independently controllable power switching devices and multiple outputs, each designed for interconnection with one of the fittings. The measuring arrangement includes multiple interconnections for connecting to the heating element and identifying resistor of each fitting to which an output is connected. The measuring arrangement measures the resistance of the heating element and the identifying resistor of each fitting connected to the apparatus.

Abstract: A method and system for controlling heating cables wherein a plurality of two-conductor heating cables are disposed in contact with heatable vessels to heat the vessels. Power lines having at least two conductors are connected to the heating cables through a plurality of first switches. Each first switch is responsive to a control signal for selectively connecting and disconnecting one heating cable to and from the power lines. Each of a plurality of remote terminals is connected to the two conductors of a heating cable and detects the temperature of the heatable vessel heated by the heating cable. At least one main controller for controlling a plurality of first switches is connected to two of the power line conductors. Temperature data relating to temperatures detected by the temperature sensors is transmitted from the remote terminals over the heating cables and the power lines by spread spectrum data transmission to the main controller.

Abstract: A vertical rapid thermal processing (RTP) system (10) is provided, comprising a vertical process chamber (20) extending along a longitudinal axis (X), and a movable platform (32) disposed within the process chamber and having a support surface upon which one or more substrates such as semiconductor wafers (W) may be mounted for processing. A temperature control subsystem (56, 58, 60) establishes a continuous temperature gradient within the vertical process chamber along the longitudinal axis. The temperature control subsystem comprises a plurality of chamber sidewall heating elements (24) located at different vertical positions along the longitudinal axis. Each of the plurality of heating elements is controlled independently of the other of the plurality of heating elements.

Abstract: A control circuit for a sauna compartment has an electrical heater therein connected to a control circuit. The control circuit allows a high voltage to flow through a first heating circuit to permit ambient air in the compartment to reach a first high temperature, at which time voltage is provided to the heater only through the second heating circuit and thence to the heater so that the ambient air in the compartment will maintain said first high temperature to prevent a person in the sauna compartment from feeling immediately chilled when the first high temperature is reached and voltage through the first heating circuit ceases to move to the heater.

Abstract: Controllers and associated methods for controlling a thermal reactor or other thermal semiconductor processors which include a heating element powered by a power source, and having profile thermocouples and spike thermocouples. One preferred method comprises the following steps: modeling thermal dynamic characteristics of the thermal reactor, the modeling step including providing thermocouple instrumented wafers in the thermal reactor, perturbing the thermal reactor by controlling the heating element using a stimulation sequence, and developing models based on changes in temperature created by the perturbations. The models are developed off-line and can include one or more models, such as a model of power versus spike thermocouple readings, a model of spike thermocouple readings versus profile thermocouple readings, and a model of profile thermocouple readings versus thermocouple instrumented wafer readings.

Abstract: An automatic control system controls a controlled variable serving as an object 2 to be controlled so that the object 2 approaches a predetermined target value, by means of an optimum regulator 4. The automatic control system include: a gain setting section 48 for setting a gain; a comparing section 48 for comparing the target value with the controlled variable serving as the object; and a weight control section 50 for weighting the gain set by the gain setting section so as to increase the weight from 0 to 1 within a predetermined period of time and for deriving a corrected manipulated variable in response to the time when a difference between the target value and the controlled variable comes within a range of a predetermined percentage of the target value, so that the corrected manipulated variable is added to the manipulated variable derived by the optimum regulator.

Abstract: An oven with high power radiant cooking elements which are capable of operating at different intensities is disclosed for cooking food quickly with infrared radiation. The conduction of this infrared radiant energy varies substantially from food to food. Accordingly, the user of the oven must develop a unique data base or recipe for each food. A recipe consists of a number of stages each of which defines the output intensity of each cooking element for a period of time. A method is disclosed for the real time development of a recipe by varying the intensity of the cooking elements during the cooking cycle, optimizing the developed recipe to reduce the number of stages, storing the optimized recipe in memory and retrieving the optimized stored recipe for future use.

Abstract: An electrically powered water heater includes a plurality of heating elements for substantially instantaneous heating of fluid passing through the heater. A controller for powering the plurality of heating elements is responsive to a temperature sensor in fluid communication with the heated fluid. The temperature sensor activates each of the plurality of heating elements for a predetermined period of time that is preferably no more than 32 half cycles. The controller activates a second heating element after a delay of preferably no more than 8 half cycles after activating a first heating element. The predetermined period of time for activating each of the plurality of heating elements may be substantially equal, such that each heating element contributes substantially equally to the heating of fluid. In one embodiment, the heater housing is provided with a plurality of chambers, and a heating element is provided within each of the plurality of chambers.

Abstract: Electric steam iron having a hot part (1) composed of a sole (7) and a steam chamber (4), the sole having a portion situated under the steam chamber, and the hot part (1) of the iron being subdivided into at least two thermal zones. A plurality of heating elements are each disposed to heat a respective one of the thermal zones and a plurality of regulation organs are each associated with a respective one of the heating elements. The at least two thermal zones include a first thermal zone (A) having at least one surface corresponding substantially to the steam chamber (4) and a second thermal zone (B) having at least one surface corresponding substantially to the portion of the sole situated under the steam chamber, the first thermal zone (A) and the second thermal zone (B) being in thermal communication with one another. The heating element which is disposed to heat the first thermal zone is arranged to at least partially heat the second thermal zone.

Abstract: A cooktop service diagnostics method which is effected by a programmable controller system, wherein the programmable controller system: a) executes a routine upon receipt of a first specified pattern of input signals to the programmable controller: b) issues an activation audible signal to indicate receipt of the specified pattern of input signals; c) issues an activation visual signal to indicate receipt of the specified pattern of input signals; d) tests cooktop heating element drivers for malfunction conditions; e) tests cooktop controller input drivers for malfunction conditions; f) issues a malfunction visual signal to indicate the existence and type of any malfunction condition; g) terminates the routine upon the receipt of a second specified pattern of input signals to the programmable controller; h) issues a deactivation visual signal to indicate termination of the routine; and i) issues a deactivation audible signal to indicate termination of the routine.

Abstract: A method and apparatus for heating a chemical used in microelectronic device fabrication processes. The apparatus includes a chemical supply and chemical bath for containing a chemical. A temperature sensor senses the temperature of the chemical contained in the chemical bath. A first heater, powered by a first electric power source, heats the chemical while it is being supplied to the chemical bath. A second heater, powered by a second electric power source, heats the chemical contained in the chemical bath. First and second power controllers regulate the first electric power and the second electric power sources, respectively, through a plurality of electrodes having different intensity levels that are selected according to the temperature of the chemical sensed by the temperature sensor.

Abstract: A PTC planar heater according to the present invention is produced by bonding one or a plurality of PTC ceramic sheets, each having a pair of electrodes formed on the surface thereof, to an insulator. The electrode pairs are electrically connected in parallel by lead wires. An insulating elastic layer covers the electrodes to prevent warpage, electrical leaks, and shorting. A thickness of the PTC ceramic sheets equal to or greater than 0.5 mm prevents warpage. Resistance is adjusted by cutting conductive paths in the electrodes or by connecting predetermined portions of the electrodes. Further, in a PTC planar unit according to the present invention, a PTC thermistor element having a pair of electrodes formed thereon is in direct contact with one side of an insulation substrate, and a insulation substrate is mounted to the other side thereof.

Abstract: An adaptive controller for controlling the temperature of a body. The adaptive controller of the present invention comprises a temperature measuring device which measures the temperature of the body. A controller which has a controller integral time constant and a controller gain constant is provided for controlling a heating device. An adjustment mechanism is provided which determines the controller integral time constant and the controller gain constant where the controller integral time constant and the controller gain constant are dependent upon the difference between the present temperature of the body and the desired temperature of the body.

Abstract: The modular multizone heater system is for controllably heating areas of a structure, for example for bonded doubler reparation. The system comprises a number of heater cells to be placed in thermal contact with the areas to be heated of the structure. Each heater cell has a heating element and a temperature sensor. The heating elements of the heater cells are connected to a heater power supply to receive electric power. The heater power supply is controlled by a control unit receiving control data from a computer. The temperature sensors of the heater cells are connected to the control unit that relays the temperature data produced by the temperature sensors to the computer for monitoring, processing and control purposes.

Abstract: Electrothermal conversion elements, apparatus and methods for use in comparing, calibrating and measuring electrical signals utilizing a thin film heater on a thin, low mass, low thermal conductivity substrate and low mass thermoresistive or PN junction thermal radiation sensors. 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 multiprobe diagnostic system for a cooking appliance using one or more heating elements, one or more error-detecting temperature sensors located near the heating element(s), one or more control temperature sensors spaced away from the error-detecting temperature sensors, and a microcomputer program for identifying and setting error conditions in the appliance based on comparisons in temperature and temperature differentials in the appliance with minimum and maximum predetermined or learned values. Other devices, such as current sensors, are used in conjunction with temperature sensors to augment the diagnostic information obtained from the temperature sensors.

Abstract: A method and system for controlling heating cables wherein a plurality of two-conductor heating cables are disposed in contact with heatable vessels to heat the vessels. Power lines having at least two conductors are connected to the heating cables through a plurality of first switches. Each first switch is responsive to a control signal for selectively connecting and disconnecting one heating cable to and from the power lines. Each of a plurality of remote terminals is connected to the two conductors of a heating cable and detects the temperature of the heatable vessel heated by the heating cable. At least one main controller for controlling a plurality of first switches is connected to two of the power line conductors. Temperature data relating to temperatures detected by the temperature sensors is transmitted from the remote terminals over the heating cables and the power lines by spread spectrum data transmission to the main controller.

Abstract: A self-calibrating temperature controller adapted for use in controlling closely the temperature of hot-melt adhesive dispensed from an adhesive supply unit is provided. The temperature controller includes a microcomputer operated under a stored program to perform automatically a self-calibrating operation. A non-volatile memory is provided for storing RTD values in a lookup table so as to compensate for the non-linearity of the RTD sensors.

Abstract: An electronic control arrangement for an electrical heating appliance with several separately heatable electrical loads, particularly cooking points or hotplates, contains an electronic master switch, which has its own power supply. The master switch is followed by a control unit having for each electrical load in each case one control subunit. For each hotplate the control unit has a temperature sensor, which responds if the control unit becomes too hot at this point.

Abstract: The invention relates to a propeller ice protection system having more evenly distributed sliding contact wear resulting in reduced maintenance, and a method of operating the system. According to the invention, polarity of a DC potential applied to the sliding contacts is periodically reversed in order to more evenly distribute brush wear. Specific hardware embodiments and various polarity reversing schemes are disclosed.

Abstract: A heating control apparatus for use in a heating system having heaters for heating at least one location and temperature sensors for measuring the temperature of each location is disclosed. The heating system is connected to an electricity supply having a tariff which varies with time. The heating control apparatus comprises a data receiving arrangement for receiving data on the tariff and weather prediction information. A selector is provided which is operable by a user to select the desired temperature for each location and a desired time and duration of the desired temperature. A controller includes a memory for storing information on the thermal characteristics of each location and the heaters and is responsive to the data, the measured temperature and the temperature selected by the user as well as the stored information to determine the times at which the heaters are to be energised. The controller then controls the heaters in order to achieve the desired temperature in each location.