> simple than others) and copied the circuit from some app note.  Both the
> inductor and FET were always hot, usually just about where you couldn't
> touch them for more than a second, even though the whole unit only took
> about 5W.

Apart from the efficiency issues, if that was a powdered iron core inductor 
(which it probably wasn't) it's life would drop by an order of magnitude or 
wore over what was expected. And many 'designers' don't realise that 
powdered iron cores can have significantly sall lifetimes.


        Russell

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