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: A spatula heating apparatus with excellent usability which overcomes drawbacks inherent to conventional gas burner type and electro-thermal type apparatuses. A spatula heating apparatus for heating spatulas 9, 9a for wax molding includes a heating coil 8 for induction-heating of spatulas 9, 9a, a heating amount setting switch 5, and an inverter control circuit 21 for supplying high frequency current to the heating coil 8 to perform heating at a preset heating amount. When high frequency current is applied to the heating coil 8, the spatulas 9, 9a are heated at the preset heating amount through electromagnetic induction.

Abstract: A method and a device for the removal of rust and paint from a metal surface, wherein induction heat is used for heating the metal surface. The device includes an electrical power supply coupled to an induction coil. A wheel and a tachometer on the device measure the velocity of the device as the wheel rotates on the metal surface. A control unit regulates the power output of the electrical power supply based upon the measured velocity of the device.

Abstract: An induction heating apparatus can heat aluminum pot etc. with pot vibration noise being suppressed. During a turn-on time of second switching device 57, an energy is accumulated at choke coil 54, and at the same time a resonant current with a shorter period than the turn-on time of second switching device 57 or a driving time of first switching device 55 is generated at heating coil 59, so that during turn-off of second switching device 57, i.e., during on-time of first switching device 55, the energy accumulated at choke coil 54 is transferred to second smoothing capacitor 62. And then the output power is supplied from smoothing capacitor 62 to heating coil 59, thereby reducing the pot vibration noise, which is caused by pulsating current of input voltage.

Abstract: Methods and Apparatus for detecting the presence of a conductor near an inductive coupling loop are disclosed. The method includes supplying an excitation to the coupling loop, measuring the signal distortion induced by the excitation signal, and monitoring the distortion in the signal for a change in harmonic content.

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply.

Abstract: An induction heating power supply is disclosed. It includes a power circuit having at least one switch and a power output. The output circuit includes an induction head. The output circuit is coupled to the power output. A controller has at least one feedback input connected to the output circuit, and has a control output connected to the switch. The controller predicts the switch zero crossing and preferably soft switches the switch. Current feedback is obtained from a coil placed between the bus bars. Each bus bar is comprised of multiple plates to increase current capacity.

Abstract: The method and apparatus are for use in automotive vehicle repair, both mechanical and body. The apparatus includes at least an eddy current/hysteretic circuit and at least one applicator functionally engaged to the circuit for obtaining a desired result when the applicator is placed into contact with structure of the vehicle to be affected by heating thereof.

Abstract: An electronic device includes a supply circuit board having a switching power supply circuit for outputting DC voltages in conformity with a type of commercial power, and a control circuit, which is connected to the supply circuit board, for performing control in accordance with the type of the commercial power. The control circuit discriminates the type of commercial power based upon a voltage value that is the result of dividing a DC voltage by the supply circuit board, and changes over control of a fixing heater in dependence upon the type of commercial power discriminated. When the door of an image forming apparatus is opened, the supply circuit board halts the supply of DC to a high-voltage circuit, thereby suppressing the generation of high voltage, and the control circuit is notified of the fact that the door has been opened.

Abstract: An induction heating and control system and method have enhanced reliability and advanced performance features for use with induction cooking devices, such as induction heating ranges. Enhanced performance is facilitated via the use of an induction heating system which integrates voltage management, power management, thermal management, digital control sensing and regulation systems, and protection systems management.

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 method and system for providing real-time, closed-loop control of the induction hardening process. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, Bsat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

Abstract: A fixing device for an image forming apparatus includes an inverter circuit for induction heating. In the inverter circuit, a main switch Q1 drives one end of a work coil L1 whose other end is connected to a power source. A serial connection of a capacitor Cs and a subswitch Q2 is connected to opposite ends of the coil L1 in parallel such that one end of the capacitor Cs is connected to the power source E. A second capacitor C1 is connected to the subswitch Q2 in parallel. For a capacitance of 0.1 &mgr;F of the capacitor C1, the factor of the coil L1 and that of the capacitor Cs are selected to be between 70 &mgr;H and 100 &mgr;H and between 1.8 &mgr;F and 5 &mgr;F, respectively. The inverter circuit is operable with optimal efficiency in the event of PWM (Pulse Width Modulation) control using a fixed frequency.

Abstract: The invention concerns an induction cooking hob with multiple inductors fed at the same frequency or multiples of a common fundamental frequency to avoid beat frequencies. Separate generators are provided for two or more heaters. A high-power heater is provided with two or more inductors. To provide maximum power, the second inductor of the high-power heater may be supplied with power switched from the generator for a different heater.

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply.

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 method of monitoring the process of induction heating a workpiece. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, Bsat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can also be used to measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

Abstract: An induction heating and control system and method have enhanced reliability and advanced performance features for use with induction cooking devices, such as induction heating ranges. Enhanced performance is facilitated via the use of an induction heating system which integrates voltage management, power management, thermal management, digital control sensing and regulation systems, and protection systems management.

Abstract: A load matching circuit is disclosed for use with a frequency controlled power supply. The load matching circuit includes an input connectable to the frequency controlled power supply and an output connectable to the load, such as an induction heating coil. A load matching section is connected between the input and the output to provide enough resonance to allow the power supply to operate at or below the maximum frequency when the load is connected to the power supply and at or above the minimum frequency when the load is disconnected from the power supply. In this manner, a solid-state variable frequency power supply can continue to run even when the external load is disconnected from the power supply.

Abstract: In an induction heating roller apparatus of the present invention, Rolling bearings 10 and a sliding bearings 14 are provided between drive shafts 2 of a roller body 1 and a support rod 9. When a trouble occurs in the rolling bearings 10, a rotational torque is transmitted from the drive shafts 2 through the rolling bearings 10 to the support rod 9. The sliding bearings 14 operate during the transmission of the rotational torque to the support rod 9, and the rolling bearings 10 slips relative to the support rod 9. The slip prevents that the support rod 9 co-rotates with the drive shafts.

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 power supply is disclosed. It includes a power circuit having at least one switch and a power output. The output circuit includes an induction head. The output circuit is coupled to the power output. A controller has at least one feedback input connected to the output circuit, and has a control output connected to the. switch. The controller predicts the switch zero crossing and preferably soft switches the switch. Current feedback is obtained from a coil placed between the bus bars. Each bus bar is comprised of multiple plates to increase current capacity.

Abstract: An induction heating power supply is disclosed. It includes a power circuit having at least one switch and a power output. The output circuit includes an induction head. The output circuit is coupled to the power output. A controller has at least one feedback input connected to the output circuit, and has a control output connected to the. switch. The controller predicts the switch zero crossing and preferably soft switches the switch. Current feedback is obtained from a-coil placed between the bus bars. Each bus bar is comprised of multiple plates to increase current capacity.

Abstract: A heating device for heating a material to be heated according to a magnetic-induction heating method includes a magnetic-field generator for generating a magnetic field, an electromagnetic-induction heating member for performing electromagnetic-induction heating by the magnetic field generated by the magnetic-field generator, a current detector for detecting a current flowing in the magnetic-field generator, a controller for controlling electric power supplied to the magnetic-field generator based on a result of detection of the current detector, and a current limiter for limiting a maximum current flowing in the magnetic-field generator based on the result of detection of the current detector.

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply.

Abstract: A temperature-regulating induction heating system is provided which comprises an induction heater (20) having apparatus (36, 38, 40) for receiving RFID transmissions and an induction heatable object (22) with an RFID tag (50). The heater (20) includes a component (28) for generating a magnetic field, control circuitry including a microprocessor (32) coupled with the component (28) for selectively initiating and terminating generation of a magnetic field; the receiving apparatus (36, 3 8, 40) provides information to the microprocessor (32) causing initiation of a heating algorithm for the object (22). In preferred forms, the tag (50) and apparatus (36, 38, 40) are designed for two-way information transfer, thereby permitting continuous updating of the information carried by tag (50). In this way, if induction heating of the object (20) is interrupted, it maybe resumed to nevertheless achieve a desired regulation temperature.

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 radio frequency (RF) power system for providing RF power to a load. The RF power system comprises a tank circuit; a direct current (DC) voltage source that provides a DC voltage within a first predetermined range; an amplifier, coupled to said DC voltage source, to provide an alternating voltage to said tank circuit; a frequency controller, coupled to said amplifier, to control a frequency of said alternating voltage provided by said amplifier; and a power sensor being coupled to said tank circuit for providing a signal to said frequency controller, wherein said frequency controller controls said frequency of said alternating voltage based on said signal provided from said power sensor.

Abstract: An induction heating power supply is disclosed. It includes a power circuit having at least one switch and a power output. The output circuit includes an induction head. The output circuit is coupled to the power output. A controller has at least one feedback input connected to the output circuit, and has a control output connected to the switch. The controller predicts the switch zero crossing and preferably soft switches the switch. Current feedback is obtained from a coil placed between the bus bars. Each bus bar is comprised of multiple plates to increase current capacity.

Abstract: A compact rice cooker with excellent rice cooking performance while preventing boiling-over is presented. This rice cooker includes a main body 31, a lid for covering the top of the main body, an inner pan detachably accommodated in the main body, a bottom heating coil for induction heating of the inner pan, a control unit for controlling high frequency power to be supplied to the bottom heating coil, and a rice gruel detecting unit disposed in a steam tube of the lid, and therefore electric power supply is controlled by the control unit depending on the detection state by the rice gruel detecting unit. The rice gruel detecting unit makes use of movement of the float due to the rise of rice gruel, and the lid is formed in a compact size, and boiling-over is prevented, so that tasty rice can be cooked.

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 RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply. According to one embodiment, the RF power supply includes a direct current (DC) voltage source that provides a DC voltage within a predetermined.

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply.

Abstract: An induction heater having an induction coil (26) for heating a metallic substance (4) hidden by a membrane (2), the metallic substance being coated with a heat activated adhesive on its side adjacent the membrane (2). The heater having four location sensor coils (36) for detecting the position of the hidden metallic substance and means to facilitate the placement of the induction coil (26) over the hidden metallic substance (4), based on information from the sensors. Once the induction coil (26) is over the metallic substance (4) it is used to heat the adhesive thereby adhering the metallic substance (4) to the membrane (2). The sensors (36) are adjacent the inductor coil (26) and are insulated therefrom by an air gap (38).

Abstract: A new apparatus for inductively soldering surface-mount, straddle-mount and through-hole type electronic components into a self-soldering PCB (printed circuit board) in an automated fashion utilizing localized Electromagnetic Induction Heating (E.I.H.). Current manufacture technology for packaging electronic components depends on the reflow and wave soldering processes. Both processes heat up to relatively high temperatures the entire assembly, namely its PCB and all the electronic components being soldered into it. Such harsh high-temperature environment frequently causes components damage resulting in rejects and/or demanding rework. With this invention reflow oven and/or wave soldering equipment is not required. During a soldering operation only the leads and pads being soldered are heated but neither the body of said electronic components nor the dielectric material forming said self-soldering PCB and its interconnecting traces are heated.

Abstract: A compact rice cooker with excellent rice cooking performance while preventing boiling-over is presented. This rice cooker comprises a main body, a lid for covering the top of the main body, an inner pan detachably accommodated in the main body, a bottom heating coil for induction heating of the inner pan, a control unit for controlling high frequency power to be supplied to the bottom heating coil, and a rice gruel detector disposed in a steam tube of the lid, and therefore electric power supply is controlled by the control unit depending on the detection state by the rice gruel detecting means. The rice gruel detector makes use of move of the float due to rice gruel, the lid is formed in a compact size, and boiling-over is prevented, so that tasty rice can be cooked.

Abstract: An induction furnace having a voltage source series inverter, a load circuit having a combination of an induction coil and a resonating capacitor bank, and control circuitry to phase lock the inverter frequency to the natural resonant frequency of the load. The capacitor bank can be divided into two groups, one across the output of the inverter and the other in series with the load. This arrangement allows for the division of the inverter voltage across the furnace coil according to the ratio of the two capacitances. The inverter uses pulse width modulation and is buffered from the load circuit by means of a small series connected inductor. Additionally, the system can have a common power supply system that supplies power in any desired proportion to a plurality of induction furnaces.

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: An induction heating power supply is disclosed. It includes a power circuit having at least one switch and a power output. The output circuit includes an induction head. The output circuit is coupled to the power output. A controller has at least one feedback input connected to the output circuit, and has a control output connected to the switch. The controller predicts the switch zero crossing and preferably soft switches the switch. Current feedback is obtained from a coil placed between the bus bars. Each bus bar is comprised of multiple plates to increase current capacity.

Abstract: A system and method for inductively heating a workpiece includes a controller and a plurality of power supplies that receive and send signals to the controller. Induction heads receive power from the power supplies. The induction heads may be aligned with adjacent segments of the workpiece, and can span the perimeter of the workpiece. The gap between adjacent induction heads is less than one half the size of the adjacent induction heads, and preferably the induction heads abut or substantially abut. Each of the power supplies include feedback for controlling the power delivered to the segments of the workpiece. In alternative embodiments the feedback may be based on the current or power provided to the induction heads, or the power provided to the workpiece.

Abstract: For use in the heating of foodstuffs by induction, use is made of an energy converter between energy taken from the mains supply via a rectifier and a high frequency oscillation. Such a converter is frequently based on the maintenance of an oscillation in a parallel resonant circuit (CR, LR) which may be disposed in a converter bridge (S1, S2, S3, S4) of controlled switches. It has turned out to enhance the efficiency considerably to let the parallel resonant circuit be series connected to a self-inductance L1 which connects it to the DC source UDC. A series resonant circuit is thereby created which is active during supply of energy and which in a simple fashion reduces the load on the participating switches.

Abstract: An induction heating fixing device is disclosed which is provided with a conducting sleeve, a coil for causing the sleeve to generate an induced current, and a high-frequency power source for feeding a high-frequency wave to the coil. This fixing device detects the switching cycle of the high-frequency power source and the electric power injected into the sleeve and, based on the detected switching cycle and the detected electric power, controls the amount of electric current to be fed from the high-frequency power source to the coil.

Abstract: A high-frequency inverter having a simple circuit construction capable of executing a constant-frequency operation and a zero-volt switching operation and an induction heating cooker using the high-frequency inverter are disclosed. The high-frequency inverter is comprised of an inverter circuit for converting a direct current from a DC power source into a high-frequency current and a control circuit for controlling the inverter circuit. The inverter circuit is comprised of: a one-transistor inverter constructed of a heating coil whose one terminal is connected to one terminal of a DC power source, a first switching element connected in series between the other terminal of the heating coil and the other terminal of the DC power source, and a first resonance capacitor connected so as to form a resonance circuit with the heating coil; and a series circuit connected in parallel with the heating coil and constructed of a second switching element and a second resonance capacitor.

Abstract: A heat retentive, temperature self-regulating, food retaining apparatus (10) includes a body (12), heat retentive core (14) and magnetic induction heating element (16). The body (12) includes a substantially rigid, heatable, food-contacting wall (18) defining a cavity (24). The core (14) is positioned in the cavity (24), and in thermal contact with the wall (18) for selective heating of the wall (18). The core (14) includes a solid state phase change material for storing latent heat during a solid-to-solid phase transformation at a phase transformation temperature. A resilient material is in contact with the phase change material to permit expansion of the phase change material during a phase transformation. The heating element (16) is in thermal contact with the core (14) for heating the core (14) to a temperature above the phase transformation temperature to effect a phase transformation in the phase change material.

Abstract: The present invention provides a circuit for heating a heating element to a desired temperature and generating an output from a single common AC power source. First, the AC power is rectified. An inductor and a capacitor form an L section type filter for the DC from the rectifier. The inductor and the capacitor have a resonate frequency that is greater than the AC power frequency. A switch is connected to the heating element. Next, a controller receives a signal that indicates the actual temperature of the heating element along with an indication of the desired temperature. The controller generates an error signal that PWMs the switch thereby controlling the heating element. Another switch is connected to a transformer. A separate controller PWMs the second switch generating the output at the secondary side of the transformer. The two controllers use a pulse width modulating frequency that is greater than the resonate frequency of the inductor and capacitor.

Abstract: In a device for the control of a circuit comprising a resonance inverter power supply for at least one load comprising an inductive component, the inverter power supply comprises at least two switches (Q.sub.1, Q.sub.2) mounted between the terminals of a DC voltage supply. The device has a current transformer (TR) comprising a primary winding (TRp) series-connected between the load and the common junction point between the switches (Q.sub.1, Q.sub.2), the freewheeling rectifiers (D.sub.1, D.sub.2) and the snubber capacitors (C.sub.1, C.sub.2); a first secondary winding (TR.sub.S1) connected between the emitter of one (Q.sub.1) of the two switches and the first terminal of a first DC supply (E.sub.1), the second supply terminal being connected to the base of the switch (Q.sub.1); a second secondary winding (TR.sub.S2) connected between the emitter of the other switch (Q.sub.2)and the first terminal of a second DC supply (E.sub.2), the second supply terminal being connected to the base of this other switch (Q.

Abstract: A high-frequency induction heater having a working coil for providing a high-frequency application of power to a sample is provided with a control circuit for controlling the amount of power to the working coil. A phase control member can be triggered to provide a first level of power to the sample to heat it below its combustion level, to thereby remove any exterior stains. Subsequently, a second level of power can be applied for a predetermined period of time to heat it to a combustion point whereby the combustion gases of the sample are free from any byproducts of the stain and an accurate measurement can be accomplished.

Abstract: An image heating apparatus includes an electroconductive heat generating element; an excitation coil for producing a magnetic flux, the excitation coil produces a magnetic flux which is effective to generate eddy current in the electroconductive heat generating element to generate heat in the electroconductive heat generating element; an electric circuit for energizing the excitation coil, the electric circuit having a series resonance circuit and a switching element connected with the series resonance circuit; electric power supply control means for controlling the switching element to effect switching between an energization state and non-energization state for the series resonance circuit.

Abstract: An adjustable width transverse flux heating apparatus for induction heating in the moving workpiece includes first and second elements disposed in the common plane to form an inductive coil. The first and second conductor elements define a middle spacing in an internal cross-section area of the inductive coil. A monitor detects workpiece fractures and generates signals relating thereto. A motor system moves one of the conductor elements relative to the other in response to the signal generated by the workpiece monitor.

Abstract: A control device particularly for induction cooking ranges with multiple heating units which comprises a plurality of induction coils. The induction coils can be electrically parallel-connectable to each other. The device also comprises elements for engaging the induction coils connecting individual induction coils or pairs of induction coils to a single electric power converter, and elements for sensing the presence or the absence of a pot or the presence of an unadapted pot on a particular induction coil; the sensor elements are electrically connected to control means that select, on user's command, the induction coils to be activated and the power to be carried to each individual induction coil, and control the sending of shares of the power generated by the electronic converter to each active induction coil, at the same time limiting the periodic variations in the current absorbed from the mains, within the limits allowed by statutory provisions regarding so-called "flicker".