[Prev][Next][Index][Thread]

RE: coil question



		-----Original Message-----
		From:	Tesla List [mailto:tesla-at-pupman-dot-com]
		Sent:	Thursday, December 23, 1999 6:26 PM
		To:	tesla-at-pupman-dot-com
		Subject:	coil question

		Original Poster: "Kelly Shutt" <tcatut-at-mail.utexas.edu> 

		OK, I'm new on the list... Never posted anything on here
before, but I have
		been keeping up with the list lately and it's great...
there's a lot of cool
		ideas being thrown about...
		anyways, on to my question... I'm working on my first coil
and having some
		trouble... my primary circuit is working great but the
secondary coil isn't
		doing jack... I'm thinking that I might now have enough
coils on it but I
		don't know... was looking for some good suggestions...
here's my coil
		specs...

		120V 60hz in, 15KV 30ma out on the transformer
		variable static spark gap....  can get about two inch sparks
with no
		trouble... so I know the primary circuit is going good

OUCH!!!  For the sake of your caps and NST, you don't *ever* want to open
your gap that wide, the voltages get extremely high!

		2 salt water caps... these have 24 bottles in each... I
haven't measured the
		caps so I don't know their ratings... I'm a little short on
money... but I'm
		guessing their close to what I need

You'll need some estimate for your cap value or else you're just shooting in
the dark.

		8.75 loops of 3/8 inch copper pipe, spaced at 1/2 inch with
an 8 inch center coil for the primary
		14awg coiled around 4.5 inch PVC, 24 inches high for the
secondary

This could be the problem.  With such a thick wire, you'll not get enough
turns and the secondary inductance will be too low, and probably impossible
to tune the primary to.  There is no reason that you need such thick wire.

		I think I need high gauge wire on the secondary but I don't
really want to
		do that if I can avoid it... any suggestions?
		also, what is good for connecting the components?  is there
anything special I should account for in my connections? like thicker wire
or anything?

		thanks,
		Kelly

You didn't say what you were using for connections, but regardless, you
should be getting something off the topload if you were in tune.  You also
didn't mention what you have for a topload, and that enters significantly
into tuning calculations.

Regards, Gary Lau
Waltham, MA USA