> > Is there a cunning way I can rig up (say) 2x lm7812's from the
> > same 15v supply to give me a regulated 24v?
>
> I've never seen a circuit using a 7812 as the reference voltage
> for another, but maybe it's possible

That is possible, but the OP wants to do that from *one 15v supply*.
That requires some step-up mechanism, inductive or capacitive or even
more esoteric.

Wouter van Ooijen

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Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products

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