toroid transformer Q

[Haible Juergen]

	>No, you're fine. The nifty thing about toroids id all of the flux
stays in the
	>core or very near to it. The flux in the center of the hole is
zero. Toroids get
	>mounted this way all the time.

The voltage induced into a wire loop is determined by all the (change of)
flux that
is comprised *inside* the area of the loop. If the mounting bolt has contact
to both
the upper and the lower metal of the enclosure, you'll get a *nice* winding
with
highest currents - just think of it, 5mm bolt, 2 mm metal enclosure, forming
a
1-turn winding that comprises the *whole* field of the toroidal transformer.
I have not tried it, but I guess with a larger transformer you could even
melt the
mounting bolt. (I remember a warning like this on a data sheet that came
with 
a toroidal.)

JH.