I'm trying to build neon john's induction heater (schematic is attached) but I'm trying to mod it in order to heat up large flat small metal sheets and since I'm using 120 VAC, I won't be drawing more then 15A. However, my problem is that my transistors, the IRFP460 are blowing up on me when I send in my 170 VDC. My schematic is similar to the one neon john has, but with some slight differences shown listed below
- R1 in the schematic is altered in such a way that it will give me a max of 50% duty ratio
- the resistor on RT of the TL494 is a 10k and is non adjustable (fixed frequency)
- C4, C5 and C9 are all film capacitors from epcos.
- C10 is roughly .66 uF and is gotten from putting three film capacitors in parallel
- L2 is made of two different coils, both 12 gauge. One is rated for .024mH and the other is rated for .0268mH. It is similar to a bifilar coil but arranged differently. See attachment for the coil. The red in the picture means it is connected at those points
If anyone can give me some advice, I appreciate it
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