An Implement 1.5 MHz of Induction Heating for Aluminum Based on Vacuum Tube Oscillator Circuit

This paper presents an implement 1.5 MHz induction heating for aluminum based on vacuum tube oscillator circuit. It is operated by supplying input voltage 220 V/50 Hz to transformer with 220 V/2.4 kV then rectify form AC to DC voltage, which is then supplied to vacuum tube oscillator circuit. It produce an AC voltage, which has the waveform with high frequency close to the resonance frequency. This paper shows the heat up for aluminum with 0.95 kilowatt power and switching frequency at 1.5 MHz, consequently the circulating current at the induction coil and the work piece, causing heat at the work piece. Experimental results, induction hardening had a high power factor equal to 0.993 in a heat up aluminum rod with 10-mm diameter from room temperature to 600 °C within time about 60 second at the maximum full load power.