Large Tesla Coil Construction Details - Help Improving The Primary

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Cameron B. Prince" <cplists@xxxxxxxxxx>

Hey guys,

With all the comments regarding the extra resistance of bronze and corona
breakdown of wood, I think I will rebuild the primary plate using HDPE with
pure copper.

I have questions regarding coupling and the alignment of the primary in
relation to the secondary. I basically followed Terry's design with the
4.25" distance between the primary and secondary. This is even though he's
using 30KV and I'm using 14.4KV. I did leave room to tighten up the coupling
somewhat if need be. How can I calculate this with more certainty?

Also, I aligned the first winding of both the primary and the secondary to
the same height. Most designs I've looked at don't specify whether there is
a difference and a lot have insulation so thick in between you can't really
see to even guess. What is the rule of thumb here?

Thanks,
Cameron


> -----Original Message-----
> From: Tesla list [mailto:tesla@xxxxxxxxxx]
> Sent: Wednesday, July 27, 2005 8:41 PM
> To: tesla@xxxxxxxxxx
> Subject: Re: Large Tesla Coil Construction Details - Comments
> Requested
>
> Original poster: "Peter Terren" <pterren@xxxxxxxxxxxx>
>
> No but it may penetrate the varnish by melting or cracking.
> When HV is in contact with wood there is corona which
> gradually carbonises a very small point next to the most
> intense corona. This becomes conductive and the process
> spreads like a cancer. It may only take a weak spot or bit of
> moisture to start.  I have this problem on my display lifter
> that has been running for months.
> To see a demonstration of wood burning from HV look at this:
> http://tesladownunder.com/misc1.htm#Wood%20burn%20fractals
>
> Peter (Tesla Downunder)
>
>
> >Original poster: "Cameron B. Prince" <cplists@xxxxxxxxxx>
> >
> >Hi Peter,
> >So you think the heat could possibly reach the wood's flash point?
> >Thanks for the input,
> >Cameron
> >
> > > > Original poster: "Peter Terren" <pterren@xxxxxxxxxxxx>
> > > I worry a little about using wood as a base for a
> multikilowatt hot
> > > primary with 20kV across the used winding.
> > > Still, looks like you can easily replace it.
>
>
>