Re: Space winding

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 4/2/02 6:50:14 AM Eastern Standard Time, tesla-at-pupman-dot-com
writes:

Greg,

I see two reasons to space wind a coil.  One is if the volts
per turn becomes too high  This is unlikely if the coil has a lot
of turns of wire.  The other reason is if close winding will give
too many turns using a given wire diameter.  This would probably
be the main reason for space winding in a typical coil.   I would
probably make a 20" coil quite tall, so I would probably space
wind using 17awg wire.  A 20% to 50% space wind probably
gives a better Q also, due to a reduced proximity effect.

Cheers,
John


>
> Hello all,
>
> Today I scored some free 400mm (16") diameter PVC piping. Although this
> would make a coil much bigger than my current power supply is capable of
> feeding, it seems a shame not to use it (it isn't cheap), and besides, I
> hope to soon have access to 25kVA ability. So I have decided to make a
> new coil. I want to wind it with about 1.2mm wire (about 17 gauge). I'm
> wondering if a coil this big should be space wound? Richard Hull says in
> the CSN guide that space winding is not really needed for coils smaller
> than 20" diameter, provided a big terminal capacity is used to offset
> the distributed capacitance of the secondary? Any suggestions? 
>
> Greg Peters