In accordance with the Faraday ’s law, the magnetic flux induction is applied for induction furnance. Induced voltage and eddy current in crucible are produced by the derivation of electromagnetic flux caused by AC voltage during the period of time (E = d/dt). As the result, heat produced by eddy current can melt the workpiece as requirement. In order to melt the aluminum work piece and transfer the energy effectively, the resonant frequency shall be applied in the full wave inverter which its switching device is MOSFET. The MOSFETs will switch from ordinary AC frequency 50 Hz to nearly the resonant frequency. The inducted melting process shall be succeeded completely by 2.3 kW electrical power required. We choose to use 30-50 kHz Frequency as the resonant frequency in this project and output power can be controlled with phase controlled by UC3879. We also use ferrite core for the matching transformer in order to minimize all losses during operation at high frequency. This can increase the eddy current in crucible and transfer the heat energy from the crucible to the workpiece at the optimum point.
By
Aornpantha Ongkasakul
Itthipon Wiphakool
Aekachai Tuntanonsakdikul
