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RE: an interesting mechanical engineering problem

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

I'm not sure that I agree with using copper stock.  If I was running my
coil using some conventional primary configuration, and then I placed a
6" x 6" sheet of copper stock on top of that primary, I suspect it would
cause losses due to eddy currents induced within the sheet.  When I
performed an experiment to compare AC resistance of various primary
conductors, a 1" x .03" copper ribbon had the lowest DC resistance by a
wide margin, but at frequencies below 100 KHz, the AC resistance of some
heavy Litz wire was significantly lower.  See

Of course Litz wire presents some difficulties in terms of being able to
experimentally tap it, but you could make just the last 20% of the coil
out of copper pipe and tap that.

Regards, Gary Lau

> Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
> Hello All,
> I'm still an advocate of using flat copper stock. Since the turns are
> further reduced in the modified plans, I would think it would want to
be at
> least 6" wide and sized in thickness to easily handle the skin depth.
> upper edge could be rounded to deter corona, especially if the
thickness is
> heavy enough.
> I thought the simplest attachment method would be to cut the
> in 3rds or fourths as transportable. The joints would be machined to
> depth to mate together in a flush manner and made as long as seems
> One side would be threaded for the bolt pattern.
> Conduction could be further improved be using a copper impregnated
> conductive grease that is used on radio tower connections, which I
have been
> using on my big discharge cap flanges. It works great to eliminate
> oxidation.
> Regards to all,
> Jim Mora