> > Looking at transorbs and zeners (with a series fuse or polyswitch) give=
s
> > me the impression that they will not save the logic chips being
> > toasted.  Any ideas?
>=20
> make your own (faster and more accurate) zener from a TL431 and a
> transistor?

On seeing the first post my reaction was a zener driving the gate of an SCR=
 to crowbar the supply on over voltage, as I have often seen in OEM power s=
upplies. A TL431 driving a low power SCR (or npn-pnp transistor pair) which=
 in turn controls the gate of a pass FET (as mentioned a couple of posts ea=
rlier in this thread) is probably a better solution.
=20
> (Hurrah, a topic that has something to do with electronics!!!)

Much better than the long 'totally OT' thread ... ;))
--=20
Scanned by iCritical.

--=20
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