Re: Novel primary designs

["Richard Kircher" <richard.kircher-at-worldnet.att-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Michael,
	Lexan is at Home Depot or Scottys here in Florida.

	I enjoyed reading some of your ideas particularly using copper flashing to
wind the primary coil.  A lot of coil pictures that I saw when first
starting into coiling (not too long ago) looked like they use this idea and
some maybe did.  But upon closer examination of those that I thought used
it or by looking at a different photo of the same coil, they did not from
what I could see.

	Anyway, I'm about to wind a primary and am interested to see what others
say about this idea so I'm glad you brought it up.  A side effect is more
self-capacitance, but this would be a good side effect IMO since the free
capacitance would save size and money on the high voltage primary
capacitor.  Also the tighter spacing would get the primary turn count and
inductance up as John Freau suggests with the great results he gets with
his coil that uses lots of primary turns.

	I have mixed feelings about multiple layer primaries and can only think of
possible negative effects, but who knows?  For sure, the computational
aspects of predicting results would be a nightmare, but then there is
always experimentation which is good fun.

Dick

At 11:08 PM 7/27/00 -0600, you wrote:
>Original poster: "acmnovak" <acmnovak-at-email.msn-dot-com> 
>
>Hello Everyone,
> 
>A while back I was kinda busy and put coiling aside for the time being, but
>now I'm getting the itch... I need to rebuild my whole system which, as I'm
>sure you all know, can be quite costly. Well... If you want a good looking,
>long lasting coil. I decided to start out with the primary and base
>structure because everything else gets bolted to it... 
>I was hoping to employ a different type of primary, but so far, all I've
>seen are flat coils made of copper tubing and lexan. Mostly, because these
>materials are the easiest to find and put togather. Does anyone know of a
>place to get info on primaries made of flat copper flashing? I've heard
>those are really efficient and easy to make. 
> 
> I would like to try out an Idea from the makers of Electrum, a primary
>that fits INSIDE the secondary. However, wouldn't that give too high of
>coupling for a conventional coil? Great Idea to save space...
> 
>How about a spiral coil wound on supports that are shaped like a parabola?
>Wouldn't that give the best distribution of magnetic flux along the length
>of the coil? As long as the focal length is the same as the height of the
>secondary. If TC frequencies propagate anything like standard RF...
>.
> 
>Has anyone experimented with litz wire primaries? That would give higher
>inductance with lower turns at high frequencies given the skin depth of TC
>tank circuits... 
>The only problem is, you wouldn't be able to select the best tap because
>you would have to make contact with all strands of the wire, thus shorting
>out the other part of the primary which takes away inductance and creates
>eddy currents. You'd have to know how many turns you need before you even
>build the coil...
>Litz wire may be succesfully employed in the tank circuit wiring, as it
>allows a wire to carry more current for it's diameter. 
> 
>The most practical of the new designs I was thinking of is not all that
>new. Simply adding another layer to a flat coil which allows the two to
>share inductance or whatever, thus requiring less turns. I've never tried
>this, myself, but it is probably the next logical step. 
> 
>I personally think that two layer copper tubing coils look the coolest : )
> 
>Could anyone fill me in as to where I could purchase Lexan? 
>I've seen this stuff in many coils and I'd like to get my hands on a big ol
>slab of it.
>Anyway, feel free to make fun of the above Ideas or add to them in any way...
>later
> 
> 
>                -Michael
>