Re: Describing coils by their diameter, was Jonathon's 6" Coil (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 30 Jun 2007 20:28:37 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Describing coils by their diameter, was Jonathon's 6" Coil (fwd)

Hi John,

Good point! I too denoted diameters with regards to efficiency, but 
should have clarified there is an assumption of the common 4:1 to 5:1 
h/d radio involved. One can also go overboard in length and that should 
also be realized. The efficiency factors I use should include h/d.

Take care,
Bart

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Fri, 29 Jun 2007 18:14:46 EDT
>From: FutureT@xxxxxxx
>To: tesla@xxxxxxxxxx
>Subject: Re: Describing coils by their diameter, was Jonathon's 6" Coil (fwd)
>
> 
>In a message dated 6/29/2007 8:11:01 A.M. US Eastern Standard Time,  
>tesla@xxxxxxxxxx writes:
>
>  
>
>> Great Performance ! but don't stop at 46". The 6.5" coil has a lot  more
>>potential. Bill Pollack and I built a 6.5" coil in 1998 that  produced 72"
>>arc's.
>>    
>>
>
>
>Lately I see folks referring to their coils by the secondary  diameter.  For
>example a *6 inch coil*, or an *8 inch coil*, etc.  Then they are  comparing
>sparks lengths, etc, for a given size diameter.  The height of a coil  is
>extremely important.  It's really more important than the  diameter.  For 
>example
>consider two coils; one is 6" x 20", the other is 6" x 32".  The 6" x  32"
>will be capable of much longer sparks because it will withstand a  much
>higher breakdown voltage, and there will be less tendency for the  sparks
>to arc to the primary.  By considering only the diameter, two people  could 
>build a 6 inch coil, and the one with the (taller)  32" height could  say, 
>"My coil
>is much better.  It gives much longer sparks".  And assuming a  good
>overall design and enough power, they would be correct.  Yet it would  not
>really be a fair comparison.  I prefer to describe the coil by
>its input power or spark length.  For example someone could say,  "This
>is my 5kW coil and it gives this certain spark length.  This could  then
>be compared with someone else's 5kW coil.  Or someone might say,
>"This is my 42" spark coil.  It uses 620 watts".  This could then  be
>compared with other coils that give 42" sparks, and the power input
>could be compared to judge the "efficiency" of the coil.  This is  not
>the engineering definition of efficiency that I'm speaking of, of  course.
> 
>John
>
>
>
>************************************** See what's free at http://www.aol.com.
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