>=A0If
> there isn't a nice path for it, it will make one. =A0That means the volta=
ge
> goes up until something arcs, smokes, punches thru, or otherwise gives up
> and allows the current to flow.

Consistent with that, (ie Olin and I are in agreement :-) ) do
understand the "special case" that I mentioned where  you  drive one
or other  end of a centre tapped stepper motor winding and the other
end of the winding rises to 2 x Vdrive. You may still need to deal
with the stored inductive energy * but you must not clamp it to less
than 2 x Vdrive or interesting things will happen (Ask me how I know
:-) ). This is not what happens with most motor drive situations, but
this sort of stepper motor is common enough that some people will
encounter this sooner or later.
* Nominally the open winding is hard coupled to the driven winding,
but Occam says that leakage inductance and Murphy mean that some sort
of clamp makes sense.


         Russell

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