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Cost-effective solutions for domestic induction heating appliances have become a priority in recent years. With this purpose, the implementation of Printed Circuit Board (PCB) inductors has entailed important research efforts. A proper litz structure is essential to achieve high-efficiency PCB inductors. This structure requires routing the traces by using vias in a double layer PCB to obtain the appropriate transposition pattern. In this paper, the optimal number of vias has been analyzed to minimize the power losses in the coil. This analysis has been carried out based on numerical calculations whose results have been experimentally verified. [ABSTRACT FROM AUTHOR]

Background: Induction heating devices using the induction coil and magnetic nanoparticles (MNPs) are the way that the magnetic hyperthermia is heading.Objective: To facilitate the induction heating of in vivo magnetic nanoparticles in hyperthermia experiments on large animals.Methods: An induction heating device using a planar coil was designed with a magnetic field frequency of 328 kHz. The coil's magnetic field distribution and the device's induction heating performance on different concentrations of magnetic nanoparticles were measured.Results: The alternating magnetic field produced in the axis position 165 mm away from the coil center is 40 Gs in amplitude; magnetic nanoparticles with a concentration higher than 80 mg. mL-1 can be heated up rapidly.Conclusion: Our results demonstrate that the device can be applied not only to in vitro and in small animal experiments of magnetic hyperthermia using MNPs, but also in large animal experiments. [ABSTRACT FROM AUTHOR]

SUMMARY We were able to reduce heating irregularities in equipment for heating beverage cans by using the high-frequency induction heating method and determining the resulting improvement in the heating efficiency. The heating irregularity between the top and bottom of the can was reduced to less than 3°C by improving the arrangement of the heating coils for the beverage can by thinning the winding and changing the circuit configuration. The efficiency of power conversion was improved from 93.0% to 97.4%. In this paper, the configuration of the equipment and the experimental results are reported. [ABSTRACT FROM AUTHOR]

Induction heating (IH) technology is nowadays the heating technology of choice in many industrial, domestic, and medical applications due to its advantages regarding efficiency, fast heating, safety, cleanness, and accurate control. Advances in key technologies, i.e., power electronics, control techniques, and magnetic component design, have allowed the development of highly reliable and cost-effective systems, making this technology readily available and ubiquitous. This paper reviews IH technology summarizing the main milestones in its development and analyzing the current state of art of IH systems in industrial, domestic, and medical applications, paying special attention to the key enabling technologies involved. Finally, an overview of future research trends and challenges is given, highlighting the promising future of IH technology. [ABSTRACT FROM PUBLISHER]

The theoretical analysis and design of an infrared (IR) thermometry system for temperature measurement in domestic induction hobs is presented together with the results of its implementation. The system includes an InGaAs PIN photodiode and a preamplifier which detects the IR radiation emitted from the bottom of the cookware and the glass–ceramic top. The analysis includes an algorithm to discount the contribution of the glass-ceramic material from the total signal. The proposed system has been designed for frying temperature measurements (140 ^\circ\C–180 ^\circ\C) and tested in the cooking range from 120 ^ \circ\C to 200 ^\circ\C for cookware made of different materials. Finally, the measurement temperature errors were around 20 ^\circ\C for almost any emissivity of the cookware. [ABSTRACT FROM PUBLISHER]

An artificial neural network model can help manufacturers determine the positions of induction heating lines and their heating parameters to form a desired shape of plate. The vertical displacements of a deformed plate are considered as the input parameters and the selected induction heating lines as output parameters to develop the model. The training patterns of neural network are obtained using an analytical solution that is derived from the plate theory to predict plate deformations in induction heating process. The plastic region in the analytical solution of the angular deformation of a steel plate is obtained from the thermal analysis of the plate with the heat input calculated from the electro-magnetic analysis of the induction heating process. [ABSTRACT FROM AUTHOR]

Abstract: The effect of radial thermal gradients in thermomechanical fatigue (TMF) specimens on the number of cycles to failure has been studied. Different radial gradients were obtained by asymmetric placement of the specimen in the coil. And by using different induction heating frequencies. The different induction frequencies give different depths of penetration for the heat. A special thermal gradient specimen was used to assess the gradients through the thickness of the specimen. Measurements performed with different induction heating coil set-ups and different heating/cooling rates show that the internal temperature varies from the external temperature. The minimum difference measured was to about ±10°C for a specimen cycled using a 400kHz coil and a heating rate of 2°C/s and the maximum ±40°C using a 10°C/s heating rate. TMF out of phase tests were performed with three different thermal gradients. Specimens tested with high heating rates exhibit more significant compressive creep compared to lower heating rates. The specimens exhibit a stress range that is 10% higher when using a coil with heating frequency of 66kHz compared to 400kHz. [Copyright &y& Elsevier]

Different shapes and orientations of an active afterheater for oxide Czochralski crystal growth systems are considered and corresponding results of electromagnetic field and volumetric heat generation have been computed using a finite element method (Flex-PDE package). For the calculations, the eddy current in the induction coil (i.e. the self-inductance effect) has been taken into account. The calculation results show the importance of an active afterheater, its shape as well as its geometry and position with respect to the crucible on the heat generation distribution in a CZ growth system. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

In this paper, the frequency-dependent resistance in Litz-wire planar windings for domestic induction heating appliances is analyzed. For these inductors, in which the size is not an essential constraint, an analytical model is developed based on the superposition of different loss effects in the wire. Eddy current losses, including conduction losses and proximity-effect losses, both internal and external, were considered and modeled. The magnetic field necessary to evaluate the external proximity losses is as well analytically calculated considering the complete winding and load properties. To verify this model and its limitations, several inductors with different wires and numbers of turns were constructed and results with both non-loaded and loaded inductors are compared with theoretical predictions. [ABSTRACT FROM AUTHOR]

Multiple-burner induction-heating cooking appliances are suitable for using multiple-output inverters. Some common approaches use several single-output inverters or a single-output inverter multiplexing the loads along the time periodically. By specifying a two-output series-resonant high-frequency inverter, a new inverter is obtained fulfilling the requirements. The synthesized converter can be considered as a two-output extension of a full-bridge topology. It allows the control of the two outputs, simultaneously and independently, up to their rated powers saving component count compared with the two-converter solution and providing a higher utilization of electronics. To verify theoretical predictions, the proposed converter is designed and tested experimentally in an induction-heating appliance prototype. A fixed-frequency control strategy is digitally implemented with good final performances for the application, including ZVS operation for active devices and a quick healing function. Although the work is focused on low-power induction heating, it can be probably useful for other power electronic applications. [ABSTRACT FROM AUTHOR]

Two V-8 engine blocks with cast-in grey iron liners were cast from a heat-treatable aluminium alloy. These blocks were instrumented by the insertion of 24 type K thermocouples placed at different points in the casting to record the thermal evolution during solidification. One of the blocks was cast after heating up the liners by induction, whereas the second was cast without the use of induction heating. The temperature–time readings from the thermocouples were obtained for thermal analysis. The solidification reactions detected were the formation of primary pre-eutectic aluminium dendrites, and two different eutectics that corresponded to Al–Si and complex Al–Si–Mg–Cu aggregates. It was found that the different solidification reactions were affected by the use of induction to heat up the liners, and by the chilling effect caused by a grey iron inset located at the bottom of the engine block moulds. The results indicate that solidification starts either at the window (bottom) or deck (top) positions in the interliners depending on whether the block was cast with or without the use of induction heating. [ABSTRACT FROM AUTHOR]

Studies cycloconverter with high-frequency tank circuit for induction heating. Waveform analysis of the tank circuit; Low-order harmonic components.

In order to process a semiconductor device of high quality, uniform heating is necessary, but it is not easy to heat uniformly with conventional induction heating equipment. To solve this problem, zone control induction heating equipment has been jointly developed. In this paper, we examine the effect of dividing an induction heater into several small coil groups having different current and frequency, using the finite-element method. We describe the heating characteristics of the zone control coil groups and show that nearly uniform heating is possible by controlling both current and frequency. [ABSTRACT FROM AUTHOR]

This paper describes the three-dimensional (3-D) modeling of an induction heating system. To realize the suitable construction of a high-frequency induction heating coil, numerical computations of eddy currents and heat conduction have been carried out by using the finite-element method (FEM) and also taking into account the dependence of material properties on temperature. For a high-frequency induction heating coil, which is normally applicable for heat treatment, the tubular solenoid design is the most appropriate due to its high coil efficiency. Coil efficiency is that part of energy delivered to the coil, which is transferred to the workpiece. Besides coil efficiency, the heating pattern and the production rate are also important. As the heating pattern reflects the coil geometry, optimal coil design is a prerequisite to attain the desired heating. Several modifications, such as spacing in between coil turns, the motion of the workpiece relative to the coil, and dimensional parameters, were carried out until optimal design was achieved. [ABSTRACT FROM AUTHOR]

This study demonstrates a novel approach to lift the inductor from the lossy substrate by static magnetic field. The lift angle of the inductor, which tuned by a position stage, is employed to control the quality factor of the inductor. The lifted inductor is then welded by localized induction heating using the ac magnetic field. Thus, the heating-induced thermal problem is prevented. In addition, the inductor is also simultaneously packaged inside a Si capping by the alternating magnetic field. To demonstrate the feasibility of the proposed concept, the meander strip inductor was fabricated and tested. The radio frequency performance of the inductor at various tilting angles away from the substrate (0, 45, and 90 deg) was characterized by using a two-port vector network analyzer. The quality factor has been improved from 4.2 (at the central frequency of 0.64 GHz) to 7.9 (at the central frequency of 0.74 GHz), as the lift angle increased from 0 to 90 deg. In other words, the central frequency of the inductor can also be varied from 0.64 to 0.74 GHz. Measurement results also indicate that the bonded Si capping has a good shear strength of 23.5 MPa. [ABSTRACT FROM AUTHOR]