Re: flat coil ?

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

Original poster: "Chris Swinson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <exxos-at-cps-games.co.uk>

Hi Bart,


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, April 27, 2002 7:41 PM
Subject: Re: flat coil ?


> Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
>
> Hi Chris,
>
> Tesla list wrote:
>
> > Original poster: "Chris Swinson by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <exxos-at-cps-games.co.uk>
> >
> > Hi Bart,
> >
> > I think im missing the point, what do you mean by "in the other
direction"
> > for Cself ? They way I work things is that they are the same for say 40"
> > high coils to flat coils, inductance looks a little more with flat
coils.
> > It looks like Cself is the same for both flat and tube coils, just
confused
> > me with what you stated :-\
> >
> > chris
>
> Sorry if I confused you. In the other direction meant increasing the hd
> ratio. I don't see a comparison
> of solenoid length to spiral width meaningful if you only select one
length
> to compare by. If you were
> to compare solenoid C or L to spiral C or L, then there should be a
> commonality (wire length is a real
> good one). At that point, you have to look at all the geometric
> possibilites keeping wire length
> unchanged and leaving turns, tpi, and hd as the variables. Keep in mind
> comparisons like this have
> boundary's of practicality (I could wind a very high capacitance solenoid
> with the same length of wire,
> but an hd of 500:1 is obvioulsy not practical, which is why I started at
> 5:1, worked down, and just
> commented on hd in the other direction).
>
> Take care,
> Bart

I did do some coil calcs with tesla coil program, and indeed if you wound a
coil 400" in dia and 3" high with the same length of wire then you can gain
a very high Cself.  Its interesting that there can be so many possible
combinations for L and  C  with the same length of wire. I wish I could try
such a high Cself coil, Would probably have to use the outside of the house
for a form that large though :)

Cheers,
Chris