Self induction heat tutorial

MOSFET full bridge inverter; Two core transformer impedance transformation, water-cooled heat, regulating auto-transformer are grid work, bus over-current protection.Before starting the production, it is necessary to clear some basic principles and concepts, that it doesn't a scratching his head.A. Heating mechanism (master literacy, skip)1.1 eddy current, as long as it is in the metal objects in the alternating magnetic field, eddy current can be generated a powerful high vortex can be rapidly warming artifacts. This mechanism in all conductors in resistivity to infinity.1.2 induction circulation, the workpiece is equivalent to a short circuit 1 turn coil, and constitute a hollow transformer, induction coil as a result of the current ratio is equal to the turns ratio is, the current on the workpiece is current in induction coil of N (number of turns) times, strong induction of short circuit current make the workpiece heated up fast. This mechanism exists in any conductor, constant magnetic flux density, the area of the workpiece and the magnetic field vector orthogonal, the greater the induced current on the workpiece, the greater the efficiency is higher. You can see from this, large flux of workpiece in cutting area than a small area of the workpiece are more likely to get high temperature.1.3 domain friction (there are innumerable in ferromagnetic body which affects approximately 10-4 m already the magnetized small regions, these small regions called magnetic domain), magnetic domain of ferromagnetic material, under the action of alternating magnetic field magnetization and inverse magnetic ring, friction, heat is produced. This mechanism is dominant in ferromagnetic materials. You can see from this, the artifacts of different materials, because the heating mechanism is different, the heating effect is different also. The ferromagnetic material are three mechanism, heating effect is best.Ferromagnetics, when heated to above the Curie point to paramagnetism, magnetic domain mechanism decline or even disappear. At this time can only rely on the remaining two mechanisms continue to heat. When artifacts across the Curie point, after the induction phenomenon is abate, equivalent impedance coil have fallen sharply, causing resonance loop current increase. Across the Curie point, after the coil inductance declines. LC circuit of the inherent resonance frequency will change. Fixed incentive way of heater efficiency of detuning or equipment damage caused.