Re: I need some help with my primary

[Terry Fritz <twftesla-at-uswest-dot-net>]

Hi Tom,

	I would use 6.5 inches for the inner turn diameter.  That gives you 1 inch
of clearance which should be fine for 10kV.

	Depending on how well coiled the wire is, maybe 0.5 inches per turn would
be good for the pitch.  My big coil has 1/4 inch tubing with 1/8th inch
spacing but that takes "skill".

	Using the equations or one of the programs, you can calculate the
inductance of your secondary coil which is a basic number.  In your case,
the secondary coil's inductance is 18.7mH  The self capacitance is 8.6 pF
If the top terminal adds say 15pF you get a resonant frequency around 240kHz.

You will tap the primary at around 6.5 turns but that is a rough guess.
You will have to play around to find the exact spot.  Of course, have extra
turns for tuning and future stuff.

Your cap is a resonant size so USE PROPERLY SET SAFETY GAPS!!!!  

The coupling from primary to secondary should be fine with the primary and
lower turn of the secondary level but be able to raise the secondary up if
racing arcs occur.

Cheers,

	Terry


At 07:22 PM 8/25/00 -0700, you wrote:
>Hi, im planning on making a new flat primary, for my
>4.5in diameter 20in high (902 turns of #24 wire)
>secondary.  I will be using 1/8in copper ground wire. 
>What i need to know is what shoud the spacing be
>between turnsbe, and whtr should the inner diameter of
>the primary coil be.  I will be pumping the coil with
>a 10kv 133ma supply, and using a ~.033uf cap.  I wanna
>do it right this time, no flashover (that will be a
>first) 
>Any help would be greatly appreciated.
>--Tom
>
>
>__________________________________________________
>Do You Yahoo!?
>Yahoo! Mail - Free email you can access from anywhere!
>http://mail.yahoo-dot-com/
>