Abstract: A power transmitting unit is provided. The power transmitting unit includes a signal generator configured to generate a signal of a first frequency band for wireless charging, a power generation circuit configured to generate a modulation signal for modulating the signal of the first frequency band generated by the signal generator, and amplify a transmit power of the signal of the first frequency band based on voltage supplied from the outside of the power transmitting unit, a power transmission circuit configured to transmit the amplified transmit power to a power receiving unit via a first antenna, a second antenna configured to receive information about a charging state from the power receiving unit through a second frequency band, and a control circuit configured to control a duty and frequency of the modulation signal based on the charging state.

Abstract: A high frequency power supply system provides highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactors with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

Abstract: A power conversion circuit encompasses a rectifying circuit, a first switching element, a second switching element, a third switching element, a fourth switching element, a series connection of a capacitor and an induction coil, a voltage detection section and a control circuit. The series connection of the capacitor and the induction coil is connected between a first connection point and a second connection point. The control circuit switches a mode between a first operation mode in which pulse signals are input to the first switching element to the fourth switching element and a second operation mode in which the pulse signals are input to the first switching element and the second switching element, the third switching element is turned off and the fourth switching element is turned on.

Abstract: A DC/DC converter 10 has a high-side transistor QH as a switching element and a low-side transistor QL as a synchronous rectifier element. A first primary electrode D and secondary primary electrode S of the high-side transistor QH are connected to an input voltage VIN and an external terminal T1, respectively. A detection transistor QD is provided in a row with the high-side transistor QH, and the ON voltage of the high-side transistor QH when ON is output as detection voltage VQD from the detection transistor QD. The output detection voltage VQD is added to a feedback voltage VFB1 by an adder CB, and inputted to a comparator CMP1. The ON period of a one-shot pulse PS1 outputted from the comparator CMP1 is regulated so as to be in direct proportion to the sum of the detection voltage VQD and the feedback voltage VFB1.

Abstract: A tuned power amplifier includes: a tuning capacitor connected in series with multiple loaded chokes that represent an inductance of an oscillator, and multiple semiconductor power switches connected to the series connections between the tuning capacitor and the loaded chokes. The loaded chokes may be induction heating coils of inductively heated fuel injectors. The induction heating coils may be connected to a common voltage source. An on state and an off state of the semiconductor power switches may be synchronized with, or at a frequency below, a natural resonant frequency of the tuned power amplifier.

Abstract: A tuned power amplifier includes: a tuning capacitor connected in series with a loaded choke that represents an inductance of an oscillator, and a semiconductor power switch connected to the series connection between the tuning capacitor and the loaded choke. The loaded choke may be an induction heating coil of an inductively heated fuel injector. The induction heating coil or the tuning capacitor may be connected to a voltage source. An on state and an off state of the semiconductor power switch may be synchronized with, or at a frequency below, a natural resonant frequency of the tuned power amplifier.

Abstract: A power supply device and method for a household appliance is disclosed. The power supply device comprises a switching converter having a rectifying stage, electrically connected with the mains, a bus capacitor, electrically connected in parallel with at least one output terminal of the rectifying stage, a first and second resonant tank, electrically connected with at least a terminal of the bus capacitor, a first and second switching device respectively having a first and second switching period and are connected respectively with the first and second resonant tank. The power supply device further comprises a control means for controlling the first and second switching device. The control means operates at least one of a first switching device independently from the operating conditions of a second switching device. The control means operates the second switching device depending on the operating conditions of the first switching device.

Abstract: A tuning system for controlling a voltage controlled oscillator is described herein. The tuning system makes use of a dual edge phase detector.

Abstract: A method of dispensing a volatile material includes the steps of providing power to a volatile material diffuser having a diffusion element and operating the diffusion element for a first period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a first duty cycle having a first on time and a first off time. Still further, the method includes the step of operating the diffusion element for a final period of time, wherein the diffusion element is continuously activated and deactivated during the final period of time at a final duty cycle having a final on time and a final off time. The first duty cycle is less than about 100% such that the first off time is greater than about 0 seconds and the final duty cycle is about 100% such that the final off time is about 0 seconds and wherein the final period of time begins after the first period of time has finished.

Abstract: A method and apparatus for rapid and selective heating of materials using variable frequency RF and microwaves. The apparatus uses variable frequency solid state electronics as a microwave power source, a novel microwave heating head to couple microwave energy to the target materials and a match-up network to tune the frequency and impedance match between the microwave source and the load. An electronic and computer measurement and control system is employed to monitor and control the microwave heating process. The method teaches the use of inductive microwave coupling for thin conductive materials such as metal film and impurity doped silicon wafers. The method also teaches the use of capacitive microwave coupling for dielectric material such as glass and ceramics. The method further teaches the use of rapid and selective heating of heterostructure for bonding and sealing of mems and integrated circuits.

Abstract: An apparatus and process are provided for induction heating of a workpiece. The workpiece is moved through an inductor to inductively heat treat the workpiece with electric power of varying frequency and duty cycle or amplitude control to control the magnitude of electric power as the frequency changes. Alternatively the workpiece may be stationary and the inductor can be moved along the workpiece, or combined and coordinated movement of both the workpiece and inductor can be used.

Abstract: A method for controlling an induction heating system of a cooking appliance provided with an induction coil, particularly for controlling it in connection with a predetermined working condition, comprises measuring the value of one electrical parameter of the induction heating system, feeding a computing model with actual switching frequency signals in order to estimate a temperature indicative of the thermal status of the heating system and to provide an estimated value of the electrical parameter, and comparing the measured electrical parameter with the estimated one and tuning the computing model on the basis of such comparison.

Abstract: A method and apparatus for rapid and selective heating of materials using variable frequency RF and microwaves. The apparatus uses variable frequency solid state electronics as a microwave power source, a novel microwave heating head to couple microwave energy to the target materials and a match-up network to tune the frequency and impedance match between the microwave source and the load. An electronic and computer measurement and control system is employed to monitor and control the microwave heating process. The method teaches the use of inductive microwave coupling for thin conductive materials such as metal film and impurity doped silicon wafers. The method also teaches the use of capacitive microwave coupling for dielectric material such as glass and ceramics. The method further teaches the use of rapid and selective heating of heterostructure for bonding and sealing of mems and integrated circuits.

Abstract: A converter (311) converts an AC electric power (e) to the DC electric power with a DC voltage value corresponding to a setting. An inverter (312) is controlled by a frequency electric power control circuit (330) to convert the DC electric power to a dual frequency AC electric power for alternately outputting low and high frequencies at a frequency ratio (duty) corresponding to the setting. A matching transformer (321) having a tap (321C) at which the resonance impedance corresponds to the output impedance of a generator (310) receives the dual frequency AC electric power. A low-frequency series resonance circuit (325) or a high-frequency series resonance circuit (326) is caused to provide a series resonance, thereby causing an induction heating coil (200) to induction heat a workpiece-to-be-heated (201). In this way, the single generator (310) and the single induction heating coil (200) are used to effectively induction heat the workpiece-to-be-heated (201) by means of the dual frequency resonance.

Abstract: An apparatus and process are provided for multi-frequency induction heating of a workpiece. Switching devices are used to selectively add, remove or reconfigure capacitive elements in the circuit to change the circuit's resonant frequency, and consequently, the frequency of induction heating or melting power transfer from the power supply to the load.

Abstract: A rectifier/inverter power supply for use with induction heating or melting apparatus includes a tuning capacitor connected across the output of the rectifier and input of the inverter. The tuning capacitor forms a resonant circuit with an inductive load coil at the operating frequency of the inverter. Additionally, the load coil may be formed from an active load coil connected to the output of the inverter and a passive load coil, in parallel with a resonant tuning capacitor.

Abstract: A heating element includes an excitation coil disposed adjacent the heating element; a voltage source for applying to the excitation coil a high frequency electric power provided by modulating an input AC electric power with a high frequency, wherein the heating element is heated by induction by the excitation coil supplied with the high frequency electric power, wherein the heating element has a characteristic frequency which is unequal to integer multiple s of a frequency of the AC electric power.

Abstract: An induction heating roller device that keeps leakage current within specifications and prevents the occurrence of erroneous operations caused by common mode noise. The induction heating roller device includes an induction coil, a grounded heating roller magnetically coupled to the induction coil and heated by electro-magnetic induction. A power factor improving capacitor is connected in parallel to and near the induction coil and has a grounded intermediate point. A high-frequency power source biases the induction coil. The leakage current produced by distributed capacitance between the induction coil and the heating roller is returned to the high-frequency power source via the power factor improving capacitor. Thus, the leakage current does not flow out of the induction heating roller device.

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 rectifier/inverter power supply for use with induction heating or melting apparatus includes a tuning capacitor connected across the output of the rectifier and input of the inverter. The tuning capacitor forms a resonant circuit with an inductive load coil at the operating frequency of the inverter. Additionally, the load coil may be formed from an active load coil connected to the output of the inverter and a passive load coil, in parallel with a resonant tuning capacitor.

Abstract: An induction heating roller apparatus that varies temperature distribution in the axial direction of a heating roller. The apparatus includes a heating roller and a plurality of induction coils arranged separately along an axial direction of the heating roller. The heating roller includes a secondary coil that is air-core transfer coupled to the induction coils. The apparatus further includes a plurality of capacitors, each being connected to one of the induction coils to form a resonance circuit. At least one of the resonance circuits has a resonance point that differs from the remaining resonance circuits.

Abstract: A heating element includes an excitation coil disposed adjacent the heating element; a voltage source for applying to the excitation coil a high frequency electric power provided by modulating an input AC electric power with a high frequency, wherein the heating element is heated by induction by the excitation coil supplied with the high frequency electric power, wherein the heating element has a characteristic frequency which is unequal to integer multiple s of a frequency of the AC electric power.

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 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 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 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 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: 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: 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: High frequency electrical heating apparatus in which metal parts are heated as they are advanced,either for annealing or forge welding purposes,and in which the electrical heating current is supplied by solid state D.C. to A.C. inverter through a load matching and frequency control circuit which maintains the desired load current and current frequency with changes in the load impedance caused by the metal parts as they are advanced.

Abstract: A high-frequency power supply which is primarily intended for use with an inductive heating apparatus. The high-frequency power supply has a pre-regulator for emitting a constant output voltage, an inverter for generating a constant output voltage, and an output network for amplifying the constant output voltage and converting the constant output voltage to a high-frequency constant output current. The power supply disclosed generates a very high frequency ac output, drives a wide range of possible loads, minimizes root mean square input current for a given output power, and can be powered from a wide range of input power sources.

Abstract: The load balancer incorporates link coil circuits that inductively couple to induction heating coils, which are connected in parallel across a power source. A capacitor is electrically connected in the link coil circuit. By varying degree to which the link coil is inductively coupled to the heating coil or by changing the capacitance, either using a variable capacitor or switching among different capacitors, changes in the amount of reactance coupled into the heating coil are effected. Thus, the current in the corresponding heating coil can be varied, enabling adjustment of the heating of the workpiece. Accordingly, the resulting system is efficient since only a single coil rather than multiple series coils are used. This aspect can be enhanced when litz cable is used in coil construction. Further, the system is compatible with active control.

Abstract: In a method for open-loop/closed-loop control of current converter valves of at least two load-guided parallel oscillating circuit inverters being supplied from a common direct current or direct voltage source and being connected in series on the DC side, each inverter has one induction furnace with a compensating conductor. Two diagonally opposed current converter valves are ignited at a time in one inverter to establish a flow of current from the source with a series-connected choke through the parallel oscillating circuit connected to that inverter. Load phase angles of the parallel oscillating circuit inverters are adjusted, resulting in arbitrarily specified individual powers of the parallel oscillating circuits wherein a maximum power that can be output by the source is taken into account, and attaining a specified ratio between the individual powers of the parallel oscillating circuits.

Abstract: An induction heater comprises a coupled pair of inverters and an induction head for generating heat, coupled to the second inverter. The output signal of the first inverter which operates at a fixed frequency, is controlled by feedback indicative of the heat output of the induction head. A control circuit processes the feedback information to compensate for power losses in the induction head. The output of the first inverter is electrically coupled to the input of the second inverter, which operates at an adjustable frequency which is selected by the user to optimize heating. The power delivered to the induction head is dependent on the output voltage of the second inverter, which is dependent on the output signal of the first inverter.

Abstract: An inductive cooking device for reducing disturbance radiation has a shielding housing with an opening in the region of a cooking (hot) plate containing an induction coil. A further coil, the ends of which are connected by a capacitor, is provided in the region of the opening.