Re: Secondary Wire?

To: tesla-at-pupman-dot-com
Subject: Re: Secondary Wire?
From: Bert Hickman <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Tue, 15 Dec 1998 17:09:06 -0700
Approved: twf-at-verinet-dot-com

Tesla List wrote:
> 
> Original Poster: mel wise <mwise44-at-flash-dot-net>
> 
> I have a source where I can get a 10" diameter pvc pipe and I have a
> question about the size of the wire I should use. This coil is going to
> be ran by a 7.2kv potential transformer, it is going to be limited to
> 2kw. I am going to be using a .07ufd cap. I am hoping for about 6 foot
> streamers or more. But by using such power what size of wire would be
> best. I currently only have a spool of 22awg and a spool of 24awg magnet
> wire, both are 8lb spools. I was wondering if 22awg wire will be able to
> carry that kind of power. I was considering winding the coil and then
> winding another layer over that and paralleling them. I know this will
> reduce the resistance and thus allow a better power transfer from the
> primary to the secondary. I am also wondering that if by winding a
> double layer coil with 22awg wire, wouldn't the two paralleled wires act
> as one single wire of a larger size. If so it should be able to
> withstand the power I want. The only other downside to using 22awg is
> going to be the amount of turns. I know for certain that the winding
> will exceed the 1000 turn mark (~1150 turns). Is it absolutely necessary
> to stay under a 1000 turns? Will it diminish any performance?
> 
> If anyone can answer these questions, please do. I need to know if this
> can work and not compromise the coils performance.
> 
> Chris Jones

Chris,

Winding 2 layers of #22, one over the other, will give you a lower
effective resistance, while leaving the inductance about the same. The
problem I see is that each layer will require about 6 pounds of wire, so
you'll need to buy another roll of wire. DON'T wind your secondary with
different wire gauges, over one another - the relative voltage
difference between adjacent turns between layers will cause immediate
shorting of your secondary. 

However, you may be able to save yourself some time and money - a
single-layer #22 gauge winding should easily handle 2-3 KVA. I pump 3-4
KVA into a similar coil made from #21 AWG with no problems whatsoever.

-- Bert --