This thesis presents a prototype of high frequency induction melting machine. Basically, an ac supply of voltage inverter use three phase autotransformer because switching devices,IRFP 460, MOSFET, is limited by voltage ratting. The type of inverter is voltage source inverter(VSI). A switching frequency of VSI is controlled by IC TL494 that is changing from 60 to 80 kHz. In addition, the output part consists of a high frequency transformer and a crucible winding. The inverter has output power approximate 3.4 KW. This prototype can operate with many materials such as copper, silver, aluminum and lead. As experimental results, the output current versus switching frequency are considered, including a kind of various material.
By
Boonsom Sartthapiriyapongsa
Shadatha Nuchnuan
Nikom Thongsawang
