Re: [TCML] how much does secondary diameter affect efficiency?

[Futuret <futuret@xxxxxxx>]

James,

If you use the 4" form, you may want to use wire that's a little thinner
than usual to keep the inductance high.  Also the form should be a little
taller than a typical 4" form.  In other words make the form almost as tall as
you would use for a 6" form.  You may probably want to use two toroids
also; a larger one above a smaller one.  This will keep the sparks farther
away from primary and ground.  By doing these things, you'll keep the
efficiency reasonably high.  In truth, this is the way to build a coil that's
compact, yet reasonably efficient.  The primary will tend to be smaller
in diameter too which will make the coil more compact.  But the toroid
must be large to get the full spark length capability.  

Your spark gap break rate will be a factor too.  Higher break rates are
less efficient but have smaller bang sizes and should stress the secondary
less.  

As you can see, there are many factors to consider overall. 

Cheers,
John



> James,>       Coil diameter has little to do with efficiency, and too large of a> secondary will make your coil look unimpressive...  Go with the 4 inch,> and don't look back...  I use 4.5 inch for about 3 kW with no problems> at all...>> Scott Bogard.>> On 2/28/2012 4:48 PM, James Hutton wrote:>> Hello, I'm about to begin building a 15kv 120ma coil.I read somewhere>> that with powers over 1.5kw, you should be using atleast 6inch PVC.I>> have lot's of spare 4inch PVC, but I can't seem to find any 6inch at any>> local hardware stores. (except for 10ft long 6inch sewage pipes for>> $70)So I'm just wondering if it is absolutely necessary to go bigger>> than 4 inch when using 1.8kw, and how much it would affect the>> efficiency of the coil if I use 4 inch instead of 6.(also, If I do use 4>> inch, how long should my windings be?)>> thanks!>>>> -James Hutton 		 	   		  _______________________________________________>> Tesla mailing list>> Tesla@xxxxxxxxxx>> http://www.pupman.com/mailman/listinfo/tesla>>> _______________________________________________> Tesla mailing list> Tesla@xxxxxxxxxx> http://www.pupman.com/mailman/listinfo/tesla>>_______________________________________________Tesla mailing listTesla@xxxxxxxxxxxxxx://www.pupman.com/mailman/listinfo/tesla
 


 
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