>I can't find any Mosfets that can handle 200-300V. The problem is not to
>source them but to find a suitable part. (Keep in mind the 20A)

1000V and 2-3A and more at 50W+ dissipation is pretty common (in isolated
TO220 too). They are manufactured for HO stages in color TVs and SMPSUs
used in 220V countries. The usual problem is the high(er) Rdson, up to 2
ohms usually.  However you can parallel almost as many as you wish (unlike
bipolars).

Peter

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