Abstract: An improved induction heating apparatus is provided for attaching membrane roofs. A top membrane layer is attached to attachment disks that hold sheets of thermal insulation to the top of roof substrates. The heating apparatus emits a magnetic field that raises the temperature of the disks and a heat-activated adhesive on top of the disks which, after cooling, becomes adhered to the bottom surface of the top membrane layer. The disks in turn are attached via fasteners to the substrate portion of the roof structure. The apparatus includes a set of bottom guides that allow a user to find the attachment disks mechanically, without actually seeing those disks beneath the top membrane layer. A fine locator circuit is provided, using a magnetic field, and the apparatus allows a user to stand upright while operating the apparatus.

Abstract: A heater unit comprises: a hot wire heating unit; an induction heating unit provided adjacent to the hot wire heating unit and operated by induction heating; and connectors each for connecting the hot wire heating unit to the induction heating unit. A cooker comprises: a casing; a heating plate provided on an upper surface of the casing; a hot wire heating unit provided on a bottom surface of the heating plate for generating heat according to application of an electric power; an induction heating unit provided on the bottom surface of the heating plate for being adjacent to the hot wire heating unit and operated by induction heating; connectors each for connecting the hot wire heating unit to the induction heating unit; and support members each provided on the bottom surface of the hot wire heating unit and for supporting the hot wire heating unit.

Abstract: Methods and devices for securing the bottom of an item of cookware to the burner of a stove top by use of magnetism. The magnet(s) may be permanent magnets or electromagnets. The cookware may comprise a permanent magnet disposed on or in the base of the cookware. The burner comprises a magnetic material such as steel or iron. The magnetic material may be in the grate of the cook top, in the electric coil of an electric burner, in the surface of a vitroceramic or smooth-top stove top, or other component of the cook top in close proximity to the bottom of the cookware when it is on the cooking surface. The magnetic source prevents the cookware from being accidentally knocked off the cook top.

Abstract: In one embodiment, an induction heating device for an induction hob has one or two coatings of insulating layers being applied to an induction coil and, above the same, a flat thermal insulation is provided. The insulating layer(s) carry on their respective upper side an electrically conductive coating connected to an earth or grounding connection so as to shunt off leakage currents, so that a user does not receive an electric shock on contacting a cooking vessel on the induction hob.

Abstract: An electric range includes a circuit board provided with at least one semiconductor chip and adapted to control an electric current to be applied to an induction heating device, a heat sink to absorb heat of the semiconductor chip to discharge the heat to the outside, and at least one heat spread clip to fix the semiconductor chip to the heat sink to conduct the heat of the semiconductor chip to the heat sink.

Abstract: Coatings with left-handed metamaterials (which are man-made materials comprising micro-structures having unusual electro-magnetic properties) are provided around an appliance, such as a hotplate or hob, incorporating induction heating coils that functions as an optical display. In one embodiment, operation of induction heating coils in the cook top alters the optical properties of the metamaterial. Thus, if the metamaterials were previously transparent, they can now become opaque. Doing so changes a display, which can be detected by an operator. This makes it possible to create an automatic operating display for an appliance, such as an induction based hob.

Abstract: An induction hob comprising a hotplate, beneath which at least one induction mechanism is situated in a housing. The housing comprises a base and lateral walls that project vertically and are connected to the hotplate. The walls delimit an inner chamber of their corresponding housing containing the induction mechanism. At least one sub-section of the housing base is configured as a one-piece plastic section.

Abstract: The invention relates to a roasting/grilling device with a roasting/grilling plate (7) and with a thermostatic regulation of the roasting/grilling power. For this the temperature of the roasting/grilling plate (7) is monitored in a contactless manner by way of electromagnetic radiation. In combination with an efficient regulation and control unit, suitably arranged heating elements, preferably induction coils (30), as well as with a special roasting/grilling plate surface, an optimal roasting/grilling of food to be roasted/grilled becomes possible, in particular due to the fact that the temperature drops which are otherwise common with roasting/grilling device are prevented.

Abstract: An induction heating apparatus wherein an electrostatic shield and the low-potential portion of an inverter circuit are electrically connected securely is provided. The induction heating apparatus in accordance with the present invention comprises a top plate 11 on which a matter 14 to be heated is placed, an induction heating coil 12 for induction heating the matter 14 to be heated, driving means 19 for driving the induction heating coil 12, and a stationary plate 15 and a cover for stationary plate 18 provided between the matter 14 to be heated and the induction heating coil 12, wherein connection portions 17a each integrated with a connection terminal 17 are electrically connected to the electrostatic shield 16 provided on the stationary plate 15 using a conductive adhesive, and the connection parts are held between the stationary plate 15 and the cover for stationary plate 18. With this configuration, the connection parts can be held securely and stably.

Abstract: An induction heating apparatus with high safety is provided in which leakage current is prevented from flowing to the human body and there is no possibility of an electric shock even when an electrostatic shielding member does not sufficiently perform its function. The driving apparatus of the present invention is an induction heating apparatus in which the electrostatic shielding member is provided between an object to be heated and an induction heating coil where sensing portion for sensing the conduction condition of the electrostatic shielding member is provided, and driving portion for driving the induction heating coil is controlled through sensing by the sensing portion.

Abstract: The invention relates to an identification system for insert elements for tempering food accommodated in containers. Advantageously, the invention can be used in particular for short-term, economic and high-quality heating of prefabricated food wherein heating can be preferably carried out in induction ovens. According to the object, the respective configuration and if possible also the equipment with containers of such an insert element shall be allowed to be recognized and taken into consideration for tempering. At the same time, the insert elements have definitely arranged containers which can be fixed in receiving means. An appropriately equipped insert element can be introduced into an induction oven or a cooling device wherein the containers of a horizontal plane are positioned at the same time. According to the invention, at least one electromagnetically or magnetically detectable element is mounted on the insert elements each in a predeterminable position.

Abstract: A frying arrangement includes a planar heating element (5) including a ferromagnetic material and constituting a frying surface. The arrangement includes at least two magnetic field generators (1, 2) each having two free ends, wherein the heating element is arranged in or close to a plane defined by the free ends. The magnetic field generators are controlled by a controller such that they are adapted to generate alternating magnetic fields in the planar heating element, wherein the magnetic fields are converted into heat in the heating element. The magnetic fields being such that the magnetic field through one of the free ends has an opposed direction as compared to the magnetic fields through the other free ends.

Abstract: A luminous device includes one or more line-shaped luminous units each including an elongated light guide, one or more light sources, and a reflective layer. The light guide has a generally flat luminous surface for emitting light and another surface disposed away from the luminous surface. The light source serves to provide light into the light guide. The reflective layer is disposed on the above-mentioned another surface of the light guide. The light guide may have a ring shape. Since the luminous device produces a continuous line-shaped luminous image, e.g., a ring-shaped luminous image, it may be used for clearly indicating a heating range of an induction heating cooker.

Abstract: A composite cooking apparatus having a body, a heating unit, an induction heating unit, and an insulating plate. The heating unit is positioned in the body to generate heat used to heat food. The induction heating unit is positioned adjacent to the heating unit to generate a magnetic field to cook the food by induction heating. The insulating plate is positioned between the heating unit and the induction heating unit to prevent heat generated from the heating unit from being transmitted to the induction heating unit. Further, the insulating plate is provided with at least one heat reflecting layer to reflect the heat generated from the heating unit.

Abstract: An induction-heating cooking device includes a light-transmissive cooking board on which a cooking container to be heated is to be placed; a heating coil for heating the cooking container; light emission means for emitting a light beam; and light-transmissive light conducting means for allowing the light beam emitted by the light emission means to be propagated therethrough. The light beam lights up an outer peripheral portion of the light conducting means.

Abstract: An electrical oven and method of controlling the same includes a heater heating unit to heat food using an electric heater; an induction heating unit to heat the food using a high-frequency current, and a control unit to drive the heater heating unit and the induction heating unit simultaneously in a preheating cooking mode. The electric oven of the present invention carries out heating by the electric heater and induction heating by high-frequency current, so preheating time required for an inner temperature of a cooking cavity to reach a preheating temperature is decreased, thereby reducing a total cooking time.

Abstract: A composite cooking apparatus having a body, a heating unit, and an induction heating unit. The heating unit is positioned in the body to generate heat used to heat food. The induction heating unit is positioned adjacent to the heating unit to generate a magnetic field to cook the food by induction heating. The induction heating unit has at least one wire, a coating of which is exposed to an electron beam to strengthen a heat resistance thereof.

Abstract: An induction heating device or work coil for heating electroconductive material to a desired temperature that can be used on a roll or cylinder of any diameter. The work coil has an open core of ferrite material shaped in a U. Wire is wound around the opposing legs of the U so that on excitation one leg becomes the N pole and the other leg becomes the S pole and the polarity alternates as the polarity of the excitation current alternates. A substantially thin rectangular flat layer of ferrite can be attached to ends of each pole piece. Each layer of ferrite has having a length sufficient to cover bottom end of each leg and a width in the direction of an axis perpendicular to the face of the U that corresponds to the width of the desired control heating effect.

Abstract: An apparatus for the heat treatment of foodstuffs and feedstuffs, in particular for the production of bakery products, such as wafer products, has a continuously moving conveying device, a device for depositing the product on the conveying device, and a device for removing the heat-treated product from the conveying device. The conveying device is formed by an endless conveyor belt that can be circulated between two return rollers and which is formed by a ferromagnetic metal strip, in particular by a steel strip. A heating device is provided on one side of the conveyor belt and includes a group of induction heaters.

Abstract: An induction heating apparatus with high safety is provided in which leakage current is prevented from flowing to the human body and there is no possibility of an electric shock even when an electrostatic shielding member does not sufficiently perform its function. The driving apparatus of the present invention is an induction heating apparatus in which the electrostatic shielding member is provided between an object to be heated and an induction heating coil where sensing portion for sensing the conduction condition of the electrostatic shielding member is provided, and driving portion for driving the induction heating coil is controlled through sensing by the sensing portion.

Abstract: A delivery apparatus is provided by the invention. The delivery apparatus includes a container for holding an article to be delivered and a heater. The container includes a housing forming an interior area and an opening. The opening is provided with a size sufficient to allow movement of the article from outside the container to within the interior area, and from within the interior area to outside the container. The heater is provided for placement within the interior area for heating the article. The heater includes an electrically conductive coil for providing an electric current when exposed to a magnetic field, and an electrical resistance heating element for generating heat. The electrical resistance heating element is provided in electrical connectivity with the electrically conductive coil. A delivery apparatus assembly is provided which includes an induction range for generating a magnetic field. A heater and a method for delivering food are provided by the invention.

Abstract: A luminous device includes one or more line-shaped luminous units each including an elongated light guide, one or more light sources, and a reflective layer. The light guide has a generally flat luminous surface for emitting light and another surface disposed away from the luminous surface. The light source serves to provide light into the light guide. The reflective layer is disposed on the above-mentioned another surface of the light guide. The light guide may have a ring shape. Since the luminous device produces a continuous line-shaped luminous image, e.g., a ring-shaped luminous image, it may be used for clearly indicating a heating range of an induction heating cooker.

Abstract: A composite cooking apparatus, which may perform a heating operation using a plane heater and an induction heating operation using high frequency current together. A composite cooking apparatus of the present invention includes a plane heater and an induction heater installed below a heat resistant glass plate, as a composite heat source. The present invention may automatically determine material of a cooking container, and perform heating and cooking using a heat source suitable for the material of the cooking container. Further, if a rapid cooking mode is set, cooking is performed at high output power using both the two heat sources, thus shortening a cooking time.

Abstract: A work plate arrangement (1) including a work plate (2) and a hot plate (3), the hot plate (3) being inserted in a recess (4) of the work plate (2). In order to provide a work plate arrangement (1) which also enables a wok to be used for cooking purposes in a simple manner, the hot plate (3) is provided with a shell (5) which is made of a glass ceramic material and which protrudes into the recess (4) of the work plate (2), the shell being used to receive a wok and having a heating device arranged thereunder (5).

Abstract: A delivery apparatus is provided by the invention. The delivery apparatus includes a container for holding an article to be delivered and a heater. The container includes a housing forming an interior area and an opening. The opening is provided with a size sufficient to allow movement of the article from outside the container to within the interior area, and from within the interior area to outside the container. The heater is provided for placement within the interior area for heating the article. The heater includes an electrically conductive coil for providing an electric current when exposed to a magnetic field, and an electrical resistance heating element for generating heat. The electrical resistance heating element is provided in electrical connectivity with the electrically conductive coil. A delivery apparatus assembly is provided which includes an induction range for generating a magnetic field. A heater and a method for delivering food are provided by the invention.

Abstract: The invention concerns a heater made of a material (5) responsive to induction and capable of sustaining high temperatures. It further comprises at least an insulating thickness with low thermal conductivity, in particular a low temperature insulation (3) and a high temperature insulation (4), said thickness being fixed at the back of the material. A field winding (2) is adjacent to the insulating thickness and separated from the material (5) by the latter.

Abstract: A heat retention system for keeping meals warm by converting induced electromagnetic energy of arisen heat. The system contains a receptacle (5, 55, 103) with passive elements (3, 53) which, via a plate (9, 59, 209), are in active connection with active elements (2, 210). Sensors (16, 18, 56, 215) and an optimised control unit (212) regulate the temperature of the meals (8) located in the receptacle (5, 55, 103), so that these meals are not cooked and energy is supplied in a directed manner. Preferably, the heat retention system is configured as a heat retention device that has a modular construction and may be dismantled into individual modules (101, 102, 103, 104) and may be assembled of individual modules (101, 102, 103, 104). For this, the individual modules include fastening devices, (105-108, 126, 135, 138, 145-148, 155, 158), such as turnbuckles (155, 158) or positive-fit fastening means (105-108, 126, 135, 138, 145-148) that correspond to the fastening devices of further modules.

Abstract: An electric heater (10) incorporates at least one heating element (20), at least one wall member (16) upstanding in the heater, and a device (42) is provided for detecting a cooking utensil (6) supported on an upper surface (4) of a cooking plate (2) overlying the heater. The device (42) comprises at least one inductively-operating loop (44) of electrically conductive material having a plurality of portions (50, 52, 54) adapted to extend over and spaced from the at least one electric heating element (20) between fixed supporting regions (56, 58, 60, 62) on the at least one wall member (16). The at least one loop (44) of electrically conductive material is such that the plurality of portions (50, 52, 54) are substantially incapable of self-support as such at normal operating temperatures of the electric heater. The plurality of portions (50, 52, 54) are supported by elongate members (64, 66, 68) of heat-withstanding material.

Abstract: An illuminating apparatus for an induction coil of an induction cooking field is in the form of a ⅓ circular ring segment and carries conducting tracks, which form turns of a coil, which is connected to several LEDs. During induction coil operation an alternating voltage is induced in the coil and consequently the LEDs are supplied. With such an illuminating apparatus it is possible without additional wiring expenditure to illuminate an induction coil under a glass ceramic cooking field.

Abstract: An induction heating device prevents an object to be heated from being displaced and buoyed from a mounting surface due to an mutual action of repulsive forces between the object to be heated and an induction heating coil. The induction heating device includes a source-current detector for detecting a source current input to a high-frequency inverter including the induction heating coil and an inverter circuit, a source-current change detector for measuring a change against time of a magnitude of the source current to detect a displacement and buoying of the object to be heated, such as a cooking pot, and a change examining unit. The controller controls an output of the high-frequency inverter in response to a detection result of the change examining unit. The induction heating device prevents the cooking pot from being displaced and buoyed even if the pot is not touched by a user at startup of heating or during the heating operation, and is inexpensive and safe.

Abstract: The invention relates to a work plate arrangement (1) comprising a work plate (2) and a hot plate (3), said hot plate (3) being inserted in a recess (4) of the work plate (2). In order to provide a work plate arrangement (1) which also enables a wok to be used for cooking purposes in a simple manner, the hot plate (3) is provided with a bowl (5) which is made of a glass ceramic material and which protrudes into the recess (4) of the work plate (2), said bowl being used to receive a wok and having a heating device arranged thereunder (5).

Abstract: An induction heatable body (22) that quickly heats to a desired temperature, retains heat long enough to be used in almost any application, and develops no “hot spots” even when heated by a heating source having an uneven magnetic field distribution. The induction-heatable body (22) achieves the foregoing while remaining relatively lightweight, inexpensive and easy to manufacture. The induction-heatable body (22) includes a plurality of induction-heatable layers (32a, b, c) each sandwiched between alternating layers of heat retentive material (34a, b, c). The induction-heatable layers (32a, b, c) consist of sheets of graphite material that can be inductively heated at magnetic field frequencies between 20 and 50 kHz. The heat-retentive layers (34a, b, c) consist of solid-to-solid phase change material such as radiation cross-linked polyethylene.

Abstract: An inverter circuit of an induction heating rice cooker which controls a switching frequency of an inverter in a variable manner according to a variation in an input voltage and drives the inverter at the controlled switching frequency. The inverter circuit comprises a power supply circuit for rectifying and filtering a commercial alternating current (AC) voltage to supply the input voltage to the induction heating rice cooker. The inverter performs a switching operation based on the input voltage from the power supply circuit to heat the rice cooker. The inverter circuit further comprises an inverter driving circuit for outputting a drive pulse to control the switching frequency of the inverter in the variable manner according to the input voltage from the power supply circuit and drive the inverter at the controlled switching frequency.

Abstract: An induction heating coil with integrated resonant capacitor is provided, along with methods of fabrication thereof, and induction heating systems employing the same. The induction heating coil includes a cable having a first conductor and a second conductor separated by a dielectric. The resonant capacitor is defined by at least a portion of the cable's first conductor and second conductor with the dielectric disposed therebetween.

Abstract: A heating apparatus includes a coil for generating a magnetic field; a heating element for generating heat by eddy currents generated by the magnetic field; an electroconductive member for generating an electromotive force by a current flowing through the coil; and an electric circuit for generating a voltage by electrical collection from the electroconductive member.

Abstract: A top plate is provided for use in a cooking device having an induction heater alone or an infrared heater in addition, which comprises a transparent crystallized glass plate, a light-shading film on a bottom surface of the glass plate and an ornamental film formed on the top surface of the glass plate. The light-shading film is a porous layer of inorganic pigment powder dispersed in glass matrix. The light-shading film has small apertures at a portion corresponding to the infrared heater. Alternatively, it has a decreased thickness at the portion. In another alternative, a luster film is used in place of the inorganic pigment layer at the portion corresponding to the infrared heater.

Abstract: An induction-heating cooking device includes: an insulating plate which is partially or entirely light-transmissive, and on which an object to be heated is placed; a heating coil provided under the insulating plate, for heating the object to be heated; a display section for indicating a portion to be heated by the heating coil through the insulating plate; and an output control section for controlling electrical conduction to the heating coil, wherein the display section includes a light emitting section which is provided in the vicinity of a magnetic flux generated by the heating coil, and the light emitting section is laid and connected radially along a radial direction of the heating coil for indicating a portion to be heated by the heating coil.

Abstract: An induction heatable body (22) that quickly heats to a desired temperature, retains heat long enough to be used in almost any application, and develops no “hot spots” even when heated by a heating source having an uneven magnetic field distribution. The induction-heatable body (22) achieves the foregoing while remaining relatively lightweight, inexpensive and easy to manufacture. The induction-heatable body (22) includes a plurality of induction-heatable layers (32a, b, c) each sandwiched between alternating layers of heat retentive material (34a, b, c). The induction-heatable layers (32a, b, c) consist of sheets of graphite material that can be inductively heated at magnetic field frequencies between 20 and 50 kHz. The heat-retentive layers (34a, b, c) consist of solid-to-solid phase change material such as radiation cross-linked polyethylene.

Abstract: An induction-heating cooking device includes a light-transmissive cooking board on which a cooking container to be heated is to be placed; a heating coil for heating the cooking container; light emission means for emitting a light beam; and light-transmissive light conducting means for allowing the light beam emitted by the light emission means to be propagated therethrough. The light beam lights up an outer peripheral portion of the light conducting means.

Abstract: An illuminating apparatus for an induction coil of an induction cooking field is in the form of a ⅓ circular ring segment and carries conducting tracks, which form turns of a coil, which is connected to several LEDs. During induction coil operation an alternating voltage is induced in the coil and consequently the LEDs are supplied. With such an illuminating apparatus it is possible without additional wiring expenditure to illuminate an induction coil under a glass ceramic cooking field.

Abstract: Temperature self-regulating food delivery systems are provided having a magnetic induction heater (32, 126) and an associated food container (76, 124) equipped with an essentially permanent ferromagnetic heating element (82, 100, 128). The heater (32, 126) and heating elements (82,100, 128) are designed so as to heat the element (82, 100, 128) to a user-selected regulation temperature when the elements (82, 100, 128) are coupled with the heater's magnetic field, and to maintain the temperature in the vicinity of the regulation temperature indefinitely temperature regulation is a heating achieved by periodically determining at least two parameters of the heaters resonant circuits related to the amplitude of the resonant current passing therethrough during heating and responsively altering the field strength of the magnetic field. Preferably, the value of the resonant circuit amplitude and the rate of change of the amplitude are determine.

Abstract: A delivery apparatus is provided by the invention. The delivery apparatus includes a container for holding an article to be delivered and a heater. The container includes a housing forming an interior area and an opening. The opening is provided with a size sufficient to allow movement of the article from outside the container to within the interior area, and from within the interior area to outside the container. The heater is provided for placement within the interior area for heating the article. The heater includes an electrically conductive coil for providing an electric current when exposed to a magnetic field, and an electrical resistance heating element for generating heat. The electrical resistance heating element is provided in electrical connectivity with the electrically conductive coil. A delivery apparatus assembly is provided which includes an induction range for generating a magnetic field. A heater and a method for delivering food are provided by the invention.

Abstract: An induction-heating cooking device includes: an insulating plate which is partially or entirely light-transmissive, and on which an object to be heated is placed; a heating coil provided under the insulating plate, for heating the object to be heated; display means for indicating a portion to be heated by the heating coil through the insulating plate; and output control means for controlling electrical conduction to the heating coil, wherein the display means includes light emitting means which is provided in the vicinity of a magnetic flux generated by the heating coil, and the light emitting means is laid and connected radially along a radial direction of the heating coil for indicating a portion to be heated by the heating coil.

Abstract: A pouch is provided for use in transporting packaged hot foodstuff such as pizza. The pouch has front and back walls, and a peripheral wall attached to the front and back walls. An induction heating element is retained in a location structure attached to the back wall for induction heating with the pouch positioned on a surface such that the wall carrying the heating element is on the surface. The element is then positioned relative to the surface for efficient induction heating to create a source of heat while the foodstuff is transported.

Abstract: A top plate is provided for use in a cooking device having an induction heater alone or an infrared heater in addition, which comprises a transparent crystallized glass plate, a light-shading film on a bottom surface of the glass plate and an ornamental film formed on the top surface of the glass plate. The light-shading film is a porous layer of inorganic pigment powder dispersed in glass matrix. The light-shading film has small apertures at a portion corresponding to the infrared heater. Alternatively, it has a decreased thickness at the portion. In another alternative, a luster film is used in place of the inorganic pigment layer at the portion corresponding to the infrared heater.

Abstract: A food carrier having inner and outer walls with insulation therebetween and ledges on the interior walls for receipt of a heated food container. A heating unit is provided which is adapted for placement on the ledges in the same manner as the food containers. The heating unit can be provided with a heating element that can be heated inductively, in an oven, or by other suitable heating. The heating element can be formed of a solid to solid phase change material or a solid to liquid phase change material or other heat retentive compositions or compounds.

Abstract: A system for heating food delivery containers which comprises: a container for delivering heated food which comprises at least one food compartment having at least one self-regulating heat storage member disposed therein, wherein the self-regulating heat storage member comprising a magnetic material and, optionally, a heat storage material; and an induction generating source which is capable of heating the heat storage material to a predetermined temperature. The system further comprises an automatic shut-off mechanism which is capable of turning off the induction generating source when the heat storage member reaches the predetermined temperature.

Abstract: The invention relates to a heat retention system for keeping warm meals by way of converting induced electromagnetic energy of arisen heat. The system contains a receptacle (5, 55, 103) with passive elements (3, 53) which via a plate (9, 59, 209) are in active connection with active elements (2, 210). Sensors (16, 18, 56, 215) and an optimised control unit (212) control and regulate the temperature of the meals (8) located in the receptacle (5, 55, 103), so that these are not cooked and energy is supplied in a directed manner. Preferably the heat retention system is configured as a heat retention device which has a modular construction and may be dismantled into individual modules (101, 102, 103, 104) and may be assembled of individual modules (101, 102, 103, 104).

Abstract: Temperature self-regulating food delivery systems are provided having a magnetic induction heater (32, 126) and an associated food container (76, 124) equipped with an essentially permanent ferromagnetic heating element (82, 100, 128). The heater (32, 126) and heating elements (82, 100, 128) are designed so as to heat the element (82, 100, 128) to a user-selected regulation temperature when the elements (82, 100, 128) are coupled with the heater's magnetic field, and to maintain the temperature in the vicinity of the regulation temperature indefinitely temperature regulation is a heating achieved by periodically determining at least two parameters of the heaters resonant circuits related to the amplitude of the resonant current passing therethrough during heating and responsively altering the field strength of the magnetic field. Preferably, the value of the resonant circuit amplitude and the rate of change of the amplitude are determine.

Abstract: Temperature self-regulating food delivery systems are provided having a magnetic induction heater (32, 126) and an associated food container (76, 124) equipped with an essentially permanent ferromagnetic heating element (82, 100, 128). The heater (32, 126) and heating elements (82,100, 128) are designed so as to heat the element (82, 100, 128) to a user-selected regulation temperature when the elements (82, 100, 128) are coupled with the heater's magnetic field, and to maintain the temperature in the vicinity of the regulation temperature indefinitely temperature regulation is a heating achieved by periodically determining at least two parameters of the heaters resonant circuits related to the amplitude of the resonant current passing therethrough during heating and responsively altering the field strength of the magnetic field. Preferably, the value of the resonant circuit amplitude and the rate of change of the amplitude are determine.