RE: Space winding question

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

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>



-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, March 15, 2001 3:31 PM
To: tesla-at-pupman-dot-com
Subject: RE: Space winding question


Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<m.j.watts-at-massey.ac.nz>

On 15 Mar 01, at 7:53, Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
>
>
>
> Malcolm -
>
> You are talking about a different problem. The wire gauge has nothing
> to do with the the spacewound 16.7 TPI as long as the wire gauge is
> not to big. If it is too big the JHCTES Ver 2.3 shows a group of stars
> to indicate to the designer that he has made a mistake in logic (the
> program maker must think of everything)!   The TPI must be coordinated
> with the gauge and the insulation thickness to give an overall
> thickness of
>
>       TPI = Turns / Overall thickness
>
> I believe that this is a problem with Bart's great program as I
> mentioned in another post. I haven't checked this out completely but
> was waiting for Bart's comments. The rest of his program gives the
> same answers as mine but Bart's has more information.
>
> The coil length is always equal to the TPI times the number of turns.

I think not. Not in a spacewound design.

-----------------------------

The spacewound design makes no difference.

   TPI = Coil length x turns

Note that whether the coil is called spacewound or closewound depends on the
AWG wire size diameter plus the insulation thickness which gives the overall
diameter. If TPI leaves no space between the insulation surfaces the coil is
called closewound. If there is space between the insulation surfaces the
coil is called spacewound. Althought elementary in concept this can be
confusing.

The overall diameter must also meet the conditions of

     TPI = 1/Overall wire diameter

     TPI x overall diameter = 1 (always)

If these two inputs are in the same program the coiler must be careful that
their product always equals one. In other words you cannot have an overall
wire diameter of 0.1 inch with 12 TPI, etc. which would be greater than one.
This is a common mistake made by coilers using manual calcs or programs.

John Couture

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