Abstract: The invention relates to a method and a circuit arrangement for preventing overheating of a cooking appliance. The arrangement includes a power circuit with a heating element and a control circuit with a coupling switch. The control circuit and the power circuit are coupled by the coupling switch. The arrangement further includes a safety switch to the control circuit. The coupling switch interrupts a power supply to the power circuit to the heating element when a limiting temperature in the cooking appliance is exceeded.

Abstract: The invention relates to a power supply for electrical domestic appliances, comprising: at least one connection to the mains electricity supply, and at least one connector for releasable electrical coupling of the power supply to a domestic appliance, wherein the power supply is also provided with measuring and control means for controlling a feed signal generated by the power supply by means of at least one control signal transmitted by a coupled domestic appliance. The invention also relates to a domestic appliance for co-action with such a power supply.

Abstract: A hotplate with a stainless steel top plate to support a vessel. The stainless steel top plate has an upper surface with a substantially centrally located depression having a depth and area generally sufficient to absorb upward crowning of the top plate when heated. A heating unit is in a heat transfer relation with the stainless steel top plate, and a base unit is connected to the heating plate assembly; however, the base unit is not fastened directly to the stainless steel top plate, so that the stainless steel top plate can expand more uniformly when heated.

Abstract: A system for detecting temperature of a cooking utensil over a radiant cooktop includes a cooktop having an upper surface and a lower surface and a radiant heating element adapted to heat the cooktop. A temperature detector is disposed adjacent the lower surface of the cooktop and is adapted to detect temperature of the lower surface of the cooktop. The system also includes a thermal insulation barrier disposed intermediate the temperature detector and the radiant heating element.

Abstract: A sensor positioned between a heat source and a heating area in parallel relationship to the heating area, for determining a mean value of the temperature of the heating area, includes a ceramic element, and a temperature-dependent resistor web attached to the ceramic element and confronting the heating area at a distance thereto. The resistor web has a length of at least 200 mm, and is electrically contacted at a contact point outside a region in which the temperature is to be ascertained.

Abstract: A semiconductor manufacturing apparatus includes: a hot plate that heats an article to be processed; a temperature control section that controls temperature of the hot plate; a main body control section that controls the entirety of the apparatus based on a process recipe; and an elevating mechanism that elevates the article to be processed above the hot plate. The semiconductor manufacturing apparatus further includes: a storage section that stores temperature data of the hot plate; an elevation control section that controls the elevating mechanism and sends elevation timing data to the storage section; a management range calculation section that calculates a management range corresponding to parameter behavior in a transient gradient state based on the temperature data, process recipe data, and the elevation timing data; and an abnormality detection section that detects apparatus abnormality with the use of the management range calculated by the management range calculation section.

Abstract: A temperature-responsive device (14) is provided for an electric heater (2). The heater (2) is located behind a heatable surface and comprises a dish-like support (6) having therein at least one electric heating element (12) having first and second terminal regions, (12A, 12B). An electrical component (18), having an electrical parameter which changes as a function of temperature, is supported inside the heater (2) by an elongate member (16). The elongate member (16) is secured to the heater (2) and extends at least partially across the heater (2). An electrically insulating carrier member (30) is secured to the elongate member (16) at a location externally of the periphery of the heater (2). The carrier member (30) has first and second side edges (32, 38) at opposite sides of the elongate member (16) and is provided with first and second electrically conductive elements (34, 40) accessible at the opposite side edges (32, 38) for electrical connection to the first and second terminal regions (12A, 12B).

Abstract: Apparatus is provided for detecting and controlling an abnormal rise in temperature associated with a combination of a cooking utensil (10) and a cooking surface (4) overlying an electric heater (6). A temperature-responsive device (24) monitors the temperature of the cooking utensil (10), while cooking utensil detection means (26) detects the location of the cooking utensil (10). Control means (30) is adapted to control energizing of the heater (6) whereby an abnormal rise in temperature associated with an event within the cooking utensil (10) is distinguished from an abnormal rise in temperature sensed by the temperature-responsive device (24) and associated with removal of the cooking utensil (10) from the cooking surface (4).

Abstract: A device warns that a surface is temperature excessive. A light guide receiving light from a light source sufficiently distant from the surface to avoid becoming dangerously hot or cold is oriented so that the light guide is in the path of the light beam and transmits the light beam through the light guide to a point outside the light guide. The light source is controlled by a controller. A predetermined warning symbol typically outside the light guide is illuminated when the surface is dangerously temperature excessive because a sensor connected to the controller ascertains and transmits the surface temperature to the controller controlling the light source and an observer sees that the surface is temperature excessive. In certain embodiments, the light guide is flexible and/or its second end movable. The symbol can illuminate a border to warn against entry into an area in which the surface is located.

Abstract: A disc-type unit 10 adjusts temperature of a control face 14 by means of a heater 12 and coolant, with a hollow plate 11 to which the heater 12 is secured, a cavity 13 formed in the hollow plate 11 and a piping 20 for supplying the coolant to the cavity 13, the piping 20 opening in the cavity 13, and the coolant being jetted to a portion to which the heater 12 is secured or a portion in proximity thereto and which shows high temperature rise when energizing the heater 12.

Abstract: The electric radiant heater (1) adapted to a cooking hob is attached to the cooking plate (2a) forming with it an air cavity (13) inside which the extended heating resistor (5) is housed on an insulating base (4). A peripheral insulating ring (6) and an outer metal tray form a peripheral external wall (3,6) defining said cavity (13) in which there is positioned a bimetal thermal switch (7), which has a compact body (7a) resting on the surface (4a) of the insulating base, and a heat receiver base (7b) in a position facing a part of the heating resistor (5). The position of the compact body (7a) relative to the heating resistor (5) is determined so as to obtain an actuating temperature point (SWC, SWO) adjusted for switching a hotplate warning light on and off.

Abstract: An embodiment of the present invention uses an on-board microcontroller of a household appliance to receive signals from a directionless encoder attached to a knob for receiving user input and processing the signals from the direction encoder according to a control algorithm. The microcontroller may increase the output to an electric heating element on the appliance based on a variety of criteria, including either direction of rotation, current heating element setting, or a change in directional rotation. Alternatively, or in addition, the microcontroller may provide various types of graduated visual or audible feedback to the user.

Abstract: A system, apparatus, and method for thermal processing of substrates undergoing lithographic chemical processes is provided. The thermal processing system includes at least one heating element, a heat distributing plate, having a heating surface and being disposed in thermal communication with the at least one heating element. The heat distributing plate is constructed and arranged to distribute heat from the heating element onto the heating surface. A substrate support, supports a substrate at a position above the heating surface and the system includes an actuator that rotates the substrate relative to the heating surface during a heat transfer operation.

Abstract: A method and device for limiting and/or controlling the surface temperature of a hob having a ceramic cooking surface. The hob is heated by an energy source which includes a temperature limiter with a variable switching temperature. The switching temperature of the temperature limiter is varied during a cooking procedure according to a redetermined switching temperature-time profile.

Abstract: A cooktop with a ceramic glass panel has a panel portion with a first indicia set for selection of a burner and a second indicia set for selection of a power level to the selected burner. Each set of indicia is associated with switches for input to a control circuit in response to manipulation by a user. In addition, each indicia set includes a display interactive with the manipulation of the other indicia set. Preferably, the control circuit includes a processor for responding only to a sequential manipulation of an indicia from the first set indicia set and a sequential manipulation of an indicia from the second set within a predetermined time period.

Abstract: A cooking hob with random positioning of pans or the like, comprising a plurality of electrical heating elements disposed within a cooking area and individually powered under the control of a control circuit, the heating elements also being used as position sensors for the pan or pans placed on the cooking area, in which a user interface is present, provided with a touch screen reproducing the cooking area and on which, for each pan placed on the cooking area, there is displayed an activatable region substantially representative of the position of the pan on the cooking area, this position being obtained from data provided by the electrical heating elements in their function as position sensors.

Abstract: The invention provides according to one example a display device for a domestic electric heating appliance, such as for example a glass ceramic hob, the electric heating appliance having at least one heating device. The latter is subdivided into several flat heating areas, which can be activated at least partly independently of one another and/or singly for heating operation. The display device optically displays the heating operation or the activation of individual heating areas. For this purpose it has individually activatable illuminating devices. The illuminating devices are constructed as separate segments of a geometrical basic shape, such as a rectangle or preferably a circle. For each display device there are two basic shapes of the same nature, but different size and having a concentric arrangement.

Abstract: An object of the present invention is to provide a ceramic heater for a semiconductor producing/examining device which is capable of accurately measuring the temperature of an object to be heated and evenly heating the whole body of a silicon wafer by adjusting the heating state of a heating element based on the temperature measurement result, and the ceramic heater for a semiconductor producing/examining device of the present invention is a ceramic heater including a ceramic substrate and a heating element formed on the surface or the inside of the ceramic substrate, wherein a temperature measurement element is formed while being brought into contact with the ceramic substrate and the surface roughness of the ceramic substrate brought into contact with the temperature measurement element is Ra?5 ?m.

Abstract: An electric cooking hob having a plurality of heating elements distributed in matrix formation below a heat-resistant surface on which one or more cooking utensils can be located in random manner. The cooking hob can determine the location, form and dimensions of one or more cooking utensils positioned on the cooking hob. The cooking hob uses a signal source to determine which heating elements lie under the cooking utensil. The cooking hob can heat the elements lying below the cooking utensil by a power source. Each heating element being able to be energized with a polarity opposite to the polarity of the current used to perform the determination, so that the power source and the signal source can be applied at the same time to different heating elements.

Abstract: A sensor assembly for a glass-ceramic cooktop appliance having at least one burner assembly disposed under a glass-ceramic plate. The sensor assembly includes an optical detector arranged to receive radiation from the glass-ceramic plate and produce an output signal corresponding to a cooktop related property of the glass-ceramic plate. A controller is provided to receive the output signal from the optical detector. The controller includes means for making a correction to said output signal for corruptive flux incident on the optical detector.

Abstract: A ceramic heater is provided, including a ceramic substrate with a heating face and a heat generator so that the temperature on the heating face may be controlled without a temperature controlling member that is separate from the substrate. The surface of the ceramic substrate includes a heating face, a first region provided apart from the heating face and a second region provided apart from the heating face. The second region has a lower emissivity of thermal radiation than that of the first region.

Abstract: A hot plate for a semiconductor producing/examining device, in which hot plate, when an object to be heated such as a silicon wafer is heated in a state that the object is distanced by a certain distance from the heating face, air is less likely to stagnate between the silicon wafer and the heating face and thus the object to be heated can be evenly heated. Specifically, the hot plate for a semiconductor producing/examining device includes a resistance heating element formed on a surface of a ceramic substrate or inside the ceramic substrate, wherein the glossiness of the heating face of the ceramic substrate is 1.5% or more.

Abstract: A glass-ceramic cooktop appliance having at least one burner assembly disposed under a glass-ceramic plate. The cooktop appliance includes a sensor assembly having a support bar mounted on the burner assembly adjacent to the glass-ceramic plate and one or more devices for sensing cooktop related properties mounted on the support bar so as to be in contact with the glass-ceramic plate.

Abstract: In a cooktop with a cooktop plate, in particular, made from glass ceramic, beneath which at least one heating element is disposed, for heating a cooking vessel to be placed on the cooktop plate, and having a temperature sensor for recording the temperature of the cooktop plate, which temperature sensor senses the temperature of the underside of the cooktop plate within the heating element and is shielded from the thermal radiation from a heating device of the heating element by insulating material, and is connected to a control unit for controlling the heating power of the heating element, to enable a good measurement accuracy to be achieved, the temperature sensor is in thermal contact with the underside of the cooktop plate by a thermally conductive element, and that the element and the temperature sensor are shielded from the thermal radiation of the heating device by insulating material.

Abstract: A sensor assembly for a glass-ceramic cooktop appliance having at least one burner assembly disposed under a glass-ceramic plate. The sensor assembly includes an optical detector arranged to receive radiation from the glass-ceramic plate and produce an output signal corresponding to a cooktop related property of the glass-ceramic plate. A controller is provided to receive the output signal from the optical detector. The controller includes means for making a correction to said output signal for corruptive flux incident on the optical detector.

Abstract: An object of the present invention is to provide a ceramic heater for a semiconductor producing/examining device which is capable of accurately measuring the temperature of an object to be heated and evenly heating the whole body of a silicon wafer by adjusting the heating state of a heating element based on the temperature measurement result, and the ceramic heater for a semiconductor producing/examining device of the present invention is a ceramic heater including a ceramic substrate and a heating element formed on the surface or the inside of the ceramic substrate, wherein a temperature measurement element is formed while being brought into contact with the ceramic substrate and the surface roughness of the ceramic substrate brought into contact with the temperature measurement element is Ra≦5 &mgr;m.

Abstract: Heat warning safety device comprising thermochromic ink or epoxy in the form of a heat warning symbol sprayed, stamped, stenciled, silk screened, embossed to the hot surfaces of appliances. The device is invisible when cold and is visible when a threshold temperature is reached. In a second version when cold the device shows only the outline of the warning symbol and when hot shows the full symbol. A plurality of these versions of the devices can be placed on various parts of appliances to maximize the effectiveness of the warning system and to tailor it both to children who need guidance as to where to look for said symbols and to adults as to whom the impact is greatest when the warning symbol appears from a point of invisibility. Alternatively, the warning symbol appears on the lip of a mug and advertises the staying power of the hot liquid therein.

Abstract: A ceramic heater capable of reducing temperature uniformity at the periphery of through holes such as insertion holes and vacuum suction holes is provided, which protects wafer against thermal shocks and has improved controllability for temperature control parts such as thermocouples and temperature fuse. Further, a ceramic heater capable of uniform resin curing is provided. A heat generation body is disposed on the surface or inside of a ceramic substrate. Further, corners for the insertion holes, the recesses and the vacuum suction holes of the ceramic substrate are chamfered.

Abstract: Heat alert safety device for warning individuals that a surface containing multiple heating elements has residual heat wherein a configuration of light emitting diodes that comprises a heat warning symbol specific that one heating element receives electric power whenever a specified temperature of that heating element is exceeded. A controller of the LEDs receives information from a heat sensor adjacent the heating element. The symbols are positioned so that an observer approaching a heating element of the stove from any direction when the heating element is dangerously hot can readily see and understand the heat warning symbol for that heating element. In one embodiment, the heat warning symbol comprises an arrangement of LED's that forms a perimeter around the heating element interrupted by the letters “HOT” or partially encircles the heating element but is positioned between the heating element and an observer approaching the heating element.

Abstract: Heat alert safety device for warning individuals that a surface is hot wherein a fiber optic cable runs from an electric light source to a heat warning symbol. The cable has a plurality of fibers connected at a first end thereof to the light source and transmits light from the light source beginning from the first end to the second end of the cable and shines light out of the second end of the cable to a predetermined symbol adjacent the second end of the cable. The symbol is readily visible when illuminated to an observer who can also readily see the surface and the symbol communicates that the surface of the stove, in particular, the heating element, is dangerously hot. A controller controls the light source Whenever a specified surface temperature is reached, the symbol is lit and remains lit as long as said specified surface temperature is maintained.

Abstract: In a cooktop having a cooktop panel, beneath which at least one heating element is disposed for heating up a vessel to be placed on the panel, and a temperature sensor sensing temperature of the underside of the panel within the heating element and connected to a control unit for controlling heating power of the heating element, to make assembly/fitting of the unit easier, the temperature sensor is fastened to an element extending from a region inside the heating element into a region outside the heating element, the element having a receiving portion inside the heating element for the temperature sensor and a fitting portion for fastening of the element, in particular, to the heating element, and/or a connection portion for connecting at least an electrical line from outside the heating element, which receiving portion lies radially offset laterally with respect to the fitting portion or connection portion.

Abstract: A cooktop comprising at least one cooktop heater and a controller coupled to the heater and operable to control operation of the heater, including cool down of the heater and drift detection, is described. In one embodiment, the cooktop further comprises a control interface coupled to the controller. The interface comprises a power setting selection unit for operator selection of a power level setting for the heater. The controller is configured to switch off supply of power to the heater if a second power level selection for the heater is a lower power level than a first power level selection, and to then resume standard heater operation once a temperature corresponding to the second power level selection is reached.

Abstract: An improved heating unit (10) used in a cooktop (12). Operation of the heating unit is by a controller (16). An electric current is applied to a composition heating element (20). The heating element is supported on a cake (24) of insulation material installed in a pan (22) located beneath a glasstop (14) of the cooktop. A thermal sensor (28) senses the temperature of the heating element and supplies an indication of the heating element temperature to the controller which changes the amount of current supplied to the heating element as a function of the sensed temperature.

Abstract: A monitor and control system that responds to alarm signals representing different hazardous conditions in an environment having a number of utility service supply lines, such as a home residence. One or more sensors coupled to the processor are each associated with one or more of the service supply lines. Each sensor produces an alarm signal in response to a hazardous condition attributable to an associated supply line. Each associated supply line is provided with a control device that is coupled to an output of the processor, and the processor is configured to produce one or more output signals in response to an alarm signal at a given input. Each control device is arranged to disable its associated supply line with respect to a sensed hazardous condition in response to a corresponding output signal from the processor.

Abstract: A description is given of a temperature detection device for an electric radiant heater, with which is associated an active sensor for detecting the positioning of a cooking vessel on a hotplate, particularly a glass ceramic plate, covering the radiant heater. This sensor is part of an inductive resonant circuit of a control means and preferably has a single sensor loop of electrically conductive material located in the vicinity of at least one heating zone heatable by electric radiant elements and preferably partly overlapping the same. According to the invention, with at least one portion the sensor loop forms a functional element of a temperature sensor of the temperature detection device. For example, a tubular sensor loop portion can serve as a supporting or protective jacket of a jacket thermocouple.

Abstract: A refrigerated oven comprising a cooking chamber in which is provided a heating elements and a refrigeration unit chamber in which is provided a refrigeration unit. The refrigeration unit is fluidly connected to the cooking chamber. Both the heating element and the refrigeration unit are selectively operable to either cool or heat the cooking chamber to thereby cool or heat a food item located therein. The refrigeration unit as preferably modular refrigeration unit that the slid into and out of the refrigeration unit chamber. Preferably, the refrigeration unit includes an evaporator that is thermally isolate is from a condenser. The condenser as preferably conductively coupled to a base supporting the elements of the modular refrigeration unit.

Abstract: A cooktop with a ceramic glass panel has a panel portion with a first indicia set for selection of a burner and a second indicia set for selection of a power level to the selected burner. Each set of indicia is associated with switches for input a control circuit in response to manipulation by a user. In addition, each indicia set includes a display interactive with the manipulation of the other indicia set. Preferably, the control circuit includes a processor for responding only to a sequential manipulation an indicia from the first indicia set and a sequential manipulation of an indicia from the second indicia set within a predetermined time.

Abstract: A heating apparatus including a stage comprising a surface having an area to support a wafer and a body, a shaft coupled to the stage, and a first and a second heating element. The first heating element is disposed within a first plane of the body of the stage. The second heating element is disposed within a second plane of the body of the stage at a greater distance from the surface of the stage than the first heating element. A reactor comprising a chamber, a resistive heater, a first temperature sensor, and a second temperature sensor. A resistive heating system for a chemical vapor deposition apparatus comprising a resistive heater.

Abstract: According to an exemplary embodiment of the invention a radiant heater (11) for a glass ceramic cooking area (25) is created. The radiant heater comprises a carrier shell (12) carrying a flat insulator (14), on which is placed a heating means (16). A thermal relay (18) projects with its tube-like sensor (19) into the central area of the radiant heater (11) and the sensor can rest on an elevation (23) of the insulator (14). By means of a holder (45) the sensor (19) can be fixed to the carrier shell (12). The holder does not project over the underside of the carrier shell (12). In one embodiment the holder with barb-like ends reaches into an opening in the carrier shell and is fixed to locking edges of the carrier shell.

Abstract: The present invention provides a radiant heating unit for a cooktop. The heating unit includes a cooking plate, a support pan, an insulation layer, a heating element, a temperature sensor, and a support post. The support pan is disposed beneath the cooking plate. The insulation layer is supported in the pan and includes an insulation base and an insulation sidewall ring. The heating element is supported on the insulation base in a spaced apart relationship to the cooking plate. The heating element is capable of radiating direct radiant energy. The temperature sensor senses the temperature inside the heating unit and includes a sensing element and lead wires. The support post has an upper head portion and a lower base portion. The upper head portion has a recess to house at least a portion of the sensing element of the temperature sensor. The recess also shields at least a portion of the sensing element from direct radiant energy of the heating element.

Abstract: The present invention provides a controller for a heating unit. The heating unit is capable of generating heat to a utensil and has a temperature sensor, a heating element, and a cooking surface. The controller has a means for measuring a temperature of a cavity within the heating unit, a means for controlling the application of power to the heating element, and a means for determining whether to control the application of power to the heating element in an overdrive state based on a type of utensil that is located on the heating unit. The present invention also includes methods of operating the controller and the heating unit.

Abstract: The present invention provides a radiant heating unit for a cooktop. The heating unit includes a cooking plate, a support pan, an insulation layer, a heating element, a temperature sensor, and a support post. The support pan is disposed beneath the cooking plate. The insulation layer is supported in the pan and includes an insulation base and an insulation sidewall ring. The heating element is supported on the insulation base in a spaced apart relationship to the cooking plate. The heating element is capable of radiating direct radiant energy. The temperature sensor senses the temperature inside the heating unit and includes a sensing element and lead wires. The support post has an upper head portion and a lower base portion. The upper head portion has a recess to house at least a portion of the sensing element of the temperature sensor. The recess also shields at least a portion of the sensing element from direct radiant energy of the heating element.

Abstract: A method for sensing overheating of a food container positioned on a glass ceramic cooking hob, for example during the preparation of a food contained in said container, electrical heating elements being provided for predefined regions of said hob. The method includes continuously measuring the variation in temperature of the region of the cooking hob during the activation of a corresponding heating element on which the container is positioned on the hob. The method further includes halting said activation when said temperature undergoes a sudden increase relative to a temperature value maintained substantially constant with time during activation of the heating element.

Abstract: The present invention provides a controller for a heating unit. The heating unit is capable of generating heat to a utensil and has a temperature sensor, a heating element, and a cooking surface. The controller has a means for measuring a temperature of a cavity within the heating unit, a means for controlling the application of power to the heating element, and a means for determining whether to control the application of power to the heating element in an overdrive state based on a type of utensil that is located on the heating unit. The present invention also includes methods of operating the controller and the heating unit.

Abstract: A device for determining the location of cooking utensils on a cooking hob comprising a plurality of thermal cells distributed in matrix formation below a heat-resistant surface on which the cooking utensil can be located in random manner, the determination of its location, form and dimensions enabling those thermal cells lying below the utensil to be energized, the same thermal cells being also individually used for this determination.

Abstract: A radiant electric heater comprises concentrically-arranged heating elements separated by a dividing wall to form inner and outer heating zones, the heater having a peripheral wall. A tunnel extends between the peripheral wall and the dividing wall. A rod-like temperature-responsive device extends through the tunnel and across the inner heating zone. An end portion of the inner element extends along the tunnel. A terminal block is located at the periphery of the heater, end portions of the inner and outer elements being electrically connected to terminals provided in the terminal block. An elongate electrically conductive link is provided having a first end electrically connected to one terminal and bridging an end portion of the outer element connected to another terminal, the link being profiled such that a second end thereof is located within the tunnel and connected to an end portion of the inner element.

Abstract: A cooktop includes a printed circuit board having an upper side and operating elements on the upper side, a glass-ceramic cooking area having a plurality of cooking locations, and display elements. Each of the display elements have an illuminator and a display-symbol mask. The illuminator is assigned to one of the operating elements, is disposed underneath the glass-ceramic cooking area, and is secured on and in contact with the upper side of the printed-circuit board. The display-symbol mask is secured on the illuminator and is disposed between the glass-ceramic cooking area and the illuminator such that, when the illuminator is in operation, a display symbol corresponding to the display-symbol mask is seen through the glass-ceramic cooking area when viewed from above the glass-ceramic cooking area. The glass-ceramic cooking area can have no printed display-symbol inscription provided thereon, and/or can have no decorative printed inscription provided in a region on the surface above the illuminator.

Abstract: An apparatus for rapidly heating a cooktop is provided. The apparatus comprises a radiant heating element positioned proximate to the cooktop. A controller is provided and is connected to the radiant heating element. The controller includes a fast heat-up circuit selectively coupled to the radiant heating element. A look-up table is selectively coupled to the fast heat-up circuit. The look-up table comprises a plurality of user power levels. Each of the plurality of user power levels is correlated to a respective user-selected temperature. The apparatus further comprises a user power input device connected to the controller. The user power input device also allows selection of at least a first of the plurality of user power levels wherein the first power level corresponds to a first respective user selected temperature in the look-up table. A temperature sensor is connected to the controller for measuring a temperature of the cooktop.

Abstract: When an object to be heated is heated without temperature nonuniformity in its heated surface, unwanted thermal deformation can be suppressed, and thermal processing precision can be improved. For this purpose, a heat transfer plate for heating a plate-like object to be heated, and a base plate are stacked. A rod heater as a heat source is inserted in the heat transfer plate. The heat transfer plate has a larger thermal conductivity and smaller creep than the base plate.

Abstract: On an electric cooker the sensor circuit (1) detects the presence of a pan (2) on each heater (F1-F4) and comprises a microcontroller (4) and a generator (6,7) that supply a high-frequency current (Ig) to a respective sensor loop (E1-E4) of each heater which generates a magnetic field, and two maximum and minimum reference signals (Vr0,Vr1) for all the heaters (F1-F4) obtained in the working temperature condition and a circuit (9-13) for measuring and evaluating the voltage (Vs) produced in each sensor loop, with a circuit part (11,11′) for demodulation into low frequency of the measuring and reference signals (Vs,Vr0,Vr1), and their differential amplification (Vm,Vrr).