Abstract: A magnetic field applicator to heat magnetic substances in biological tissue, having a magnetic yoke with two pole shoes across from each other and separated from each other by a distance that defines the magnetic field exposure volume produced by the applicator, and with two magnetic coils, one assigned to each of the two pole shoes, to produce a magnetic field. The magnetic yoke and the pole shoes consist of ferrite segments assembled together. The pole shoes oppose each other and are surrounded by magnetic disk-shaped coils with one or more windings extending helicoidally, which creates an intermediate air gap between the pole shoes and coils. This results in a magnetic field applicator with the ability to effectively and efficiently administer hyperthermia and thermo-ablation procedures to destroy cancerous tissue in a patient, as well as having uses in other medical and industrial applications.

Abstract: A method and apparatus for heating specimens in wells of a metallic specimen carrier. The specimen carrier is heated by applying resistive heating directly to the carrier. An AC source and transformer may be used where the specimen carrier is in series with a single turn secondary winding of the transformer. A magnet may be placed in each well and excited by the heating current to provided a stirring effect.

Abstract: The invention concerns an induction system for heating, re-heating and keeping warm a food container combining an armature beneath the container, an induction device supporting the container optimised for the safety of the user, the electromagnetic compatibility, and preserving the induction device since the induction is activated only in the presence of an appropriate armature.

Abstract: A transverse flux induction heating apparatus adjusts the level of edge heating of a workpiece by changing the pole pitch of induction coils forming the apparatus to provide a more uniform transverse temperature of the workpiece. Changes in the operating frequency of the induction power supply and in the distance between induction coils and workpiece are not required to adjust edge frequency heating. The pole pitch, and therefore, the level of edge heating can be continuously changed, or conveniently adjusted prior to a production run, in a high speed continuous heat treatment process for a workpiece.

Abstract: A method for induction heating a workpiece made of a material such as ferrous material or alloy is carried out by placing a non-magnetic conductive shield in proximity to a current concentrating surface of the workpiece and exposing the workpiece with a shield in place to a time varying magnetic field. The magnetic field induces eddy currents in the surface of the workpiece. The conductive shield is placed in sufficient proximity to reduce or eliminate the eddy currents in the portion covered by the shield. At least a part of the uncovered portion of the workpiece is heated above the austenitizing or solution temperature of the material. At the same time, the covered portions of the workpiece are protected from overheating by the shield. The workpiece is then quenched to complete the hardening process.

Abstract: A magnetic field applicator to heat magnetic substances in biological tissue, having a magnetic yoke with two pole shoes across from each other and separated from each other by a distance that defines the magnetic field exposure volume produced by the applicator, and with two magnetic coils, one assigned to each of the two pole shoes, to produce a magnetic field. The magnetic yoke and the pole shoes consist of ferrite segments assembled together. Additionally, the magnetic field applicator is composed of a magnetic yoke having two parallel vertical yoke elements of identical geometry spaced apart a distance from each other, and two transverse yoke elements disposed between said vertical yoke elements. The pole shoes, surrounded by disk-shaped magnetic coils, are attached to the center of said transverse yoke elements and oppose each other over a prescribed distance.

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 magnetic heating device comprising three electrical coils, each coil being wound around a respective magnetic yoke having a gap therein, the three yokes being arranged such that the gaps are adjacent to each other or coincident, an article to be heated being located, in use, in the gaps in the three yokes, so as to direct the magnrtic field generated in each yoke by its respective coil through the articles, each coil being connected to a respective different phase of a three phase low frequency alternating electrical supply, and one of the coils being wound in the opposite direction to the other two coil.

Abstract: A fixing device using induction heating includes an endless member having a metal layer of a conductive material; and an electromagnetic induction coil arranged close to said endless member, alternating current being supplied to said coil, thereby generating heat to heat up said endless member, said coil being wound onto a core member arranged in a width direction of said endless member, and an expansion of a folded portion of said coil being absorbed by a narrower portion of said core member, thereby maintaining to be constant the width of a gap between said coil and said endless member.

Abstract: A method for transverse flux induction heating using a heating machine including an iron core, that essentially has a U-shape with an opening facing downwards. The legs lie in contact with downwards facing displaceable core jaws. These are so arranged that they are displaceable towards and from each other by means of pneumatic pistons. The object that is to be heated is placed between the core jaws. The core jaws are at the displacement guided by means of U-shaped rails and rolls or linear bearings. The displacement serves among other things to free the object that is to be heated or has been heated for transport into and out from the machine. When the right position has been reached the displacement is stopped and the two core jaws are locked by a pressurized bellow pressing the core jaws upwards against the legs of the U-shaped core.

Abstract: A heating device for the electromagnetic induction heating of a metal strip traveling in a specified direction. The device includes at least one electric coil arranged opposite at least one of the large surfaces of the strip so as to heat the latter by transverse magnetic flux induction, each coil being associated with at least one magnetic circuit. Each circuit is divided into a plurality of magnetically independent bars arranged parallel to the direction of travel of the strip. The bars may moved toward or away one another thereby adapting to the width of the strip and distributing the magnetic flux across the width of the strip.

Abstract: An induction heating device having a hollow cylindrical body made of electrically conductive material, at least one primary induction coil and at least one auxiliary induction coil, the at least one primary induction coil and the at least one auxiliary induction coil being arranged in the cavity of the cylindrical body such that, by means of the at least one primary induction coil and the at least one auxiliary induction coil, first and second magnetic fields, respectively, can be produced in the cylindrical body. The at least one auxiliary induction coil and the at least one primary induction coil operate such that the second magnetic field, at least in one area of the cylindrical body, counteracts the first magnetic field. A corresponding method of operating such an induction heating device, and also a processor for processing a recording medium, having such an induction heating device, are also provided.

Abstract: A heat generator for reducing emissions includes a permanently magnetized, disc-shaped rotor; a stator axially separated from the rotor and in which the rotor induces electric currents as it rotates to generate heat in the stator; and an adjoining cooling duct through which a cooling liquid flows to dissipate heat generated in the stator. The rotor and stator are axially movable in relation to one another to adjust the heat generated in the stator. Heat output is controlled by a member acting axially on the rotor in the direction of the stator with a variable force against the action of a repelling force, and includes a soft magnetic material forming part of the stator. The permanently magnetized rotor and the stator are magnetically attracted to one another, and it is possible to strengthen/weaken their to achieve a predetermined output/speed profile.

Abstract: By freely adjusting the heat generation distribution of an object to be heated, the heat generation distribution which matches a purpose can be easily obtained. In an electromagnetic induction heating device including an object to be heated having at least an electromagnetic induction heat generating layer and a magnetic field generating unit which is arranged toward the electromagnetic induction heat generating layer of the object to be heated in an opposed manner and includes an exciting coil which generates a magnetic flux penetrating the electromagnetic induction generating layer, a magnetic flux adjusting member which is made to be interlinked with a portion of the magnetic flux of the exciting coil to generate an electromagnetic induction action so that the magnetic flux acting on the electromagnetic induction heat generating layer is changed is disposed in the vicinity of the exciting coil.

Abstract: In transverse flux induction heating of electrically conductive strip, conductors that cross the strip width are stacked, or connected, such that a multiple of the induced current flows across the strip width as compared to that which flows along the strip edges. Conductors across the width of the strip and conductors along the edges of the strip are connected in series to insure that the current which flows in the conductors is everywhere the same. In the case of two stacked cross conductors, this gives an I2R heating of four times the heating across the strip width as compared to that along the strip edges.

Abstract: A transverse flux induction heating apparatus adjusts the level of edge heating of a workpiece by changing the pole pitch of induction coils forming the apparatus to provide a more uniform transverse temperature of the workpiece. Changes in the operating frequency of the induction power supply and in the distance between induction coils and workpiece are not required to adjust edge frequency heating. The pole pitch, and therefore, the level of edge heating can be continuously changed, or conveniently adjusted prior to a production run, in a high speed continuous heat treatment process for a workpiece.

Abstract: A magnetic ferrite core used in an image heating apparatus has a disadvantage that in spite of having a sufficient surplus in an effective cross-sectional area relative to necessary magnetic flux density, it must be used while having a minimum thickness which is conversely determined in molding. Furthermore, since a ferrite core is a sintered article, the core is weak to shock of collision a fall or the like. These advantages are solved by an image heating apparatus of the induction heating type having the strength of a core.

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: An induction heating apparatus used as a fixing apparatus of a copying machine, a printer, and the like includes a first coil for generating a magnetic field to induce an eddy current in a heating member, a second coil for cancelling the magnetic field generated by the first coil, and a third coil connected to the second coil and wound in a direction opposite from the winding direction of the second coil. The induction heating apparatus permits an efficient use of power.

Abstract: Device for the electromagnetic induction heating of a metal strip travelling in a specified direction comprising at least one electric coil arranged opposite at least one of the large faces of the said strip so as to heat the latter by transverse magnetic flux induction, each coil being associated with at least one magnetic circuit, each circuit being divided into a plurality of mutually uncoupled magnetic bars arranged parallel to the direction of travel of the strip, the said magnetic circuit, consisting of the said plurality of mutually independent bars, adapts to the width of the strip to be heated by moving the said bars away from or towards one another, in such a way as to continuously adapt the distribution of the said magnetic flux to the characteristic dimensions of the said strip.

Abstract: A device for heating a cooling vessel for keeping warm the food contained in the vessel. A mobile support is provided for the vessel in which are arranged a supply module comprising a source of live electric energy including a high frequency voltage selector supplied by the source and at least a flat inductor of fine thickness supplied by the voltage selector. The source of electric energy generating an electromagnetic field perpendicular to the support plane and a flat armature of fine thickness made up of completely closed spires and placed under the vessel parallel to the supporting table.

Abstract: The tool comprises one or more core-coil assemblies 2 jacketed in an non-magnetic and electrically insulating, tubular outer housing, 10. The housing enables high power transfer efficiency. A structural skeleton 20 extends longitudinally through the tool for axially reinforcement. The core-coil assemblies 2 are encapsulated in epoxy 77 to mechanically rigidify and protect them as well as to isolate the coil windings 51 from the power bus 23 extending longitudinally of the core-coil assemblies through a peripheral busway 60, 61.

Abstract: C-shaped inductors for induction heating a heated steel material that is carried via table rollers. Each C-shaped inductor includes a C-shaped iron core having a pair of legs facing each other by sandwiching a gap through which the heated steel material passes, and heating coils wound around the pair of legs of the C-shaped iron core. A ring-shaped iron core for restricting induced currents generated in the heated steel material is disposed near the C-shaped inductors, and the heated steel material passes through the gap of each C-shaped inductor.

Abstract: An induction heating system for a thermal roller comprises a rotatable hollow roller jacket having flanges at opposite ends thereof, the flanges concentrically surrounding the axis of the roller jacket and the roller jacket defining an enclosed space, and an inductor arranged within the enclosed space and inductively coupled with the roller jacket, the inductor consisting of an inductor spool through which a current flows and a magnetic core formed by the roller jacket, the inductor spool comprising a plurality of elongated outer current conductors peripherally arrayed close to an inner surface of the roller jacket and extending parallel to the axis at least across the greatest surface width of the roller jacket, the inductive coupling with the roller jacket being adjustable in zones, and flanges concentrically surrounding the axis, the roller jacket flanges forming bearings for the inductor spool flanges.

Abstract: An apparatus and method is provided for conductively bonding at least two conductors together. An inductive coil generates a magnetic field when electrical current is run therethrough. A magnetic concentrator is disposed near the inductive coil and adjacent which the two conductors can be positioned for concentrating the magnetic field on the conductors. The concentrator is independent of the conductors. Pressure is applied to the conductors. The concentrator concentrates the magnetic field generated by the inductive coil on the conductors, thereby heating the conductors under pressure and electrically bonding the conductors together.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: A transverse flux heating coil is disclosed to inductively heat a continuous run of wire. In general, the transverse flux heating coil includes a single loop conductive element having a pair of termination ends extending therefrom and connectable to a power supply. The single loop conductive element is constructed to distribute the majority of the current across a width of the single loop conductive element and forms an internal heating area in which a continuous run of wire is fed therethrough. The flux generated by the current is generally transverse to a direction of travel of the wire through the heating coil. The transverse flux heating coil includes a first conductor having a width facing an internal heating area that is substantially greater than a thickness and is constructed of planar copper bar stock.

Abstract: An electrophotography fixing device has a heating roller and an induction heating device. In order to improve heat resistance, heat radiating performance and insulation performance and in order to appropriately uniformly heat the heating roller, in the induction heating device, induction heating coils wound onto a core are fixed by varnish mixed with mica, and the outside surfaces thereof are fixed by a heat resistant bundling band or a molded body of a heat resistant material, or coated with a heat resistant, insulating and thermal conductive sheet. Alternatively, the same sheets as the above described sheet are provided between the core and the coils and between the layers of the coils. In addition, the core is formed with a hole extending in axial directions or holes extending in directions perpendicular to the axial directions. Moreover, the coils are doubly insulated.

Abstract: The object of the present invention is to provide an induction heating fusing device in which the rotary heating member, such as a fusing roller or fusing belt, may be easily replaced. In order to attain this objective, the induction heating fusing device has a core, which forms a closed magnetic circuit, that comprises a first core component that runs though the empty space of the fusing roller, and a second core component that exists outside the empty space of the fusing roller, said core components being separable. The fusing roller, first core component and induction coil are housed in a casing, and comprise a fusing unit that may be replaceably mounted to the main unit of an image forming apparatus. During replacement of the fusing unit, the second core component remains in the image forming apparatus. The induction heating fusing device also has a pressurization means that causes the end surfaces of the first core component and the end surfaces of the second core component to be in pressure contact.

Abstract: An apparatus and method is provided for conductively bonding at least two conductors together. An inductive coil generates a magnetic field when electrical current is run therethrough. A magnetic concentrator is disposed near the inductive coil and adjacent which the two conductors can be positioned for concentrating the magnetic field on the conductors. The concentrator is independent of the conductors. Pressure is applied to the conductors. The concentrator concentrates the magnetic field generated by the inductive coil on the conductors, thereby heating the conductors under pressure and electrically bonding the conductors together.

Abstract: A dish-shaped core for an induction heating apparatus is provided with rim parts which present a large area to the edge of the cooking vessel. These rim parts are obtained by means of a slanted cut of the rim or by slanting the rim itself inwards. The leakage flux is reduced because the edge of the cooking vessel acts as an “attractor” for the flux lines emanating from the core.

Abstract: Method and apparatus for joining metal pieces using induction heating. Metal pieces to be joined are placed end-to-end with a gap between them and induction heated in the thickness portion. To maximize speed and even heating edge-to-edge of the ends, members of a magnetic substance are provided in a gap between the inductor and the piece to be heated, thereby enhancing local heating effect by increasing magnetic flux density. Once heated, the ends are pressed together end-to-end for joining.

Abstract: Induction heating apparatus for use in welding an end of a first length of pipe (26) to the exterior surface of a second length of pipe (28), consists of heating assemblies (20, 24) each comprising at least one electrical induction coil (32, 36) wound on an annular, laminated, magnetic core assembly (30, 34). The lowermost surfaces of said core assembly (30, 34) define a saddle shape adapted to be seated on the exterior surface of said second length of pipe (28). The arrangement of the coils (32, 36) and the core assemblies (30, 34) is such that substantially all of the magnetic flux generated when the apparatus is seated on the pipe (28) and the coil is energised is contained within the core assembly and within the wall of the pipe (28). Advantageously, the core assemblies (30, 34) have E-sections profiles, the ends of the limbs of the E-sections comprising the lowermost surfaces of the core assemblies and the coils being wound about the central limbs of the E-sections.

Abstract: An induction heating or cooking apparatus comprises an inductive heating coil (L), means (CT) for sensing the current I.sub.s of an AC supply applied to the heating coil (L), means (VR) for selecting the desired heat output of the apparatus, means (APC) for comparing the sensed current with in output of the selecting means (VR), and means (RL1) for varying a the voltage of the supply to the heating coil (L) in accordance with the value of an error signal output from the comparing means (APC). Thus, the temperature which the base of a cooking utensil (P) stood on the coil (L) reaches is independent of the material of the utensil.

Abstract: A cooking apparatus includes a fan 13 provided at the top wall of a heating chamber 2 with its front face directed downwards. A spiral coil 14 in the form of a flat disc is provided around a rotation shaft 12 above the heating chamber 2. When high-frequency current is supplied to the coil 14, the coil 14 generates an alternating magnetic flux. The magnetic flux penetrates a shielding plate 16 and the fan 13, whereby the fan 13 is inductively heated. The fan 13 draws air from the heating chamber 2 and propels the air back to the heating chamber 2, where the air is heated when it contacts the fan 13. As a result, the temperature in the heating chamber rises, so that an object placed on a turntable 5 is cooked. By such a constitution, it is not necessary to keep additional space open for a heating element because the fan 13 functions as a heating element. Accordingly, it is possible to enlarge the diameter of the fan 13 so that the blowing efficiency is enhanced.

Abstract: A core structure for induction heating apparatus consists of radially disposed core parts carrying cylindrical coils for energization. The core parts join the outer end to form a rim and at the center to form a central pole.

Abstract: An induction sealing apparatus for inductively sealing a cover to a container where the shape of the cover and the shape of the container and the shape of the induction sealing apparatus are different from each other with the induction sealing apparatus directing the magnetic field proximate magnetic focusing members that direct the induction energy into specific regions of the cover so that so that the cover can be heated sufficiently to seal the cover to the container.

Abstract: A fixing device is provided, which can maintain good fixing properties, irrespective of the kind of a material on which a developer image is to be fixed and a temperature condition of a pressure roller. In a rotary contact region between a heat supply medium and the pressure roller, pressure and heat are applied to the material, thereby fixing the developer image on the material. The heat supply medium includes a metallic body for induction heating, which is provided with a magnetic field to produce an eddy current. The heat supply medium contains a magnetic field generating unit. The magnetic field generating unit includes a core provided with a coil. The core is situated near the metallic body of the heat supply medium such that a distance between a position closest to the metallic body and an end portion of the core is less than a distance between magnetic force line guiding portions provided on the core.

Abstract: A sheet bar joining apparatus comprises a heater provided between a delivery-side clamp for clamping a rear end of a preceding sheet bar and an entry-side clamp for clamping a front end of a succeeding sheet bar; upper and lower anti-buckling plates provided on the entry-side clamp and located above and below the sheet bars; upper comb tooth portions and lower comb tooth portions formed in the upper and lower anti-buckling plates, respectively; a heat resistant insulator provided at a surface of each comb tooth portion opposed to the sheet bars; and a plurality of groove portions provided near the surface of each comb tooth portion opposed to the sheet bars.

Abstract: A getter heating coil assembly producing a focused magnetic field for heating objects in close proximity to the coil assembly. The coil assembly comprises electrical conductors wound on a coil bobbin, the coil bobbin having a central spindle around which the conductors are wound. The wound bobbin is assembled with a magnetic field concentrator, said field concentrator having a central core extending from a base, and a side wall extending from the base to enclose the wound bobbin. The central core of the field concentrator fits within the spindle on the bobbin and extends through it. The coil bobbin remains exposed on one side for emission of focused electromagnetic energy when alternating current is supplied to the coil windings. A button of high magnetic permeability material may be attached to the field concentrator for focusing the emitted electromagnetic energy toward the center of the coil.

Abstract: A hot water beverage maker uses a voltage transformer type heating unit to heat water flowing to the filtering vessel. The water flows from a water reservoir to a wound transformer where the water passes through metal tubing that is also the secondary winding of the transformer. The secondary winding is shorted. The water to be heated then flows to the filtering vessel that may contain coffee or tea. The water flows through the filtering vessel to a carafe for serving.

Abstract: A heating roller device which incorporates a metal roller having a curier temperature adjusted to an appropriate level and enabling a self-temperature-controllability and which has a structure that the metal roller is induction-heated by an induction heating section. A method of manufacturing the foregoing metal roller according to the present invention has a step of joining a pipe, which is made of temperature-sensitive magnetic metal, and the composition of which has been adjusted so as to have a predetermined curier temperature, and metal having a resistivity lower than that of the temperature-sensitive magnetic metal to each other by a drawing work in such a manner as to prevent formation of any gap. Thus, an induction heating pipe exhibiting an excellent heating characteristic is manufactured.

Abstract: High frequency reactors for interconnecting a high frequency electrical power source and a load which reactors include a pair of plates having opposite surfaces with a length and width and a thickness between the surfaces which is small relative to the length and width of the surfaces. The plates are disposed with opposing closely spaced surfaces insulated from each other, and each of the plates has longitudinally aligned first and second portions with one portion of one of the plates electrically insulated from another portion of the plates and conductively interconnected by a variable reactance with another portion of the plates.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: A device for heating a press tool (4), which is mounted in a press (3) for manufacturing products wholly or partially of plastic or composite, consists of a core (1) of electric sheet steel, a coil arrangement (9, 10, 11) placed around the core (1), and a voltage source (12). The voltage source (12) is connected to the coil arrangement (9, 10, 11) for generating a magnetic field in and around the core (1). The core (1) has two poles (8a, 8b) which, between themselves, receive the press tool (4) and are displaceable in relation to one another for applying a press force to the press tool (4) and conduct the generated magnetic field into the press tool (4). A press (3) comprises such a heating device and is used in a manufacturing method where the press tool (4) is heated by the magnetic field supplied thereto.

Abstract: A high frequency bar type heater can be inserted into a hole of an object to be heated even if there is an obstruction above the hole. The high frequency bar type heater has a flexible and slender heat resisting and insulating tube (2) having both its ends closed so as to form a water-tight container. A flexible and slender conductor coil (3) is inserted in the heat resisting and insulating tube (2). A magnetic core (5), sectioned in plural pieces in its longitudinal direction, is contained on an inner side of the conductor coil (3). A flexible cooling water pipe (6) is inserted in the heat resisting and insulating tube (2) so as to cool the interior thereof. The high frequency bar type heater thus has flexibility as a whole. The magnetic core may also be formed of a flexible material.

Abstract: A method and apparatus for induction brazing wherein the induction coil's power is controlled by a closed loop temperature controller which is provided a temperature signal from a temperature sensor located proximate the brazed joint. Power is supplied to the induction coil until temperature reaches a specific set point corresponding to the desired brazing temperature of the alloy.

Abstract: A ripple current generator for an induction heating apparatus includes a resonant circuit with a current injecting self-inducting coil (6), a capacitor (13), an induction heating coil (14) and a high-frequency controlled power switch (12). The current injecting self-inducting coil (6) is saturable and mounted in series with a parallel assembly consisting of two arms; a first arm (B.sub.1) containing the switch (12) and a second arm (B.sub.2) containing a capacitor (13) mounted in series with the induction heating coil (14). The self-inducting coil includes a magnetic circuit that automatically reaches saturation during the resonance phase of the oscillating circuit. The generator is useful in household cooking appliances such as induction plates, cookers or deep fryers, as well as industrial induction heating equipment for treating metal components.

Abstract: An induction heater for heating a portion of a load comprises a side entry coil driven by a source of alternating current, with a flux concentrator located at the coil opening. The coil produces a magnetic field in the region occupied by the flux concentrator and the heated portion of the load. The flux concentrator extends along the opening of the coil and is fabricated of high permeability, low loss material, such as nickel-zinc ferrite, so as to enhance the uniformity of the magnetic field generated within the coil. In the preferred application, heating produces a complete fluid block in a cable section within the coil without overheating or damaging the cable.

Abstract: An inductive device can heat a body having a slender bore, with an inductor assembly that includes a coolant system. The assembly has a parallel pair of elongate inductors sized to fit deep inside the bore. Each of these inductors has a distal end and a proximal end. The distal ends of the inductors can be electrically interconnected. These inductors are adapted at their proximal ends to connect to a source of current for circulating current along the inductors. The coolant system is adapted to communicate with a source of coolant to circulate coolant along the inductors. The inductors are inserted through the bore of the body to lie lengthwise, without coiling, along the length of the bore. Coolant can then be pumped along the elongate inductors. Then by driving alternating current to flow through the inductors, magnetic coupling to the body occurs to produce heating effects.