Re: need fast tesla help PLEASE

From: 	Chip Atkinson[SMTP:chip-at-XiG-dot-com]
Reply To: 	Chip Atkinson
Sent: 	Monday, December 08, 1997 5:17 AM
To: 	Tesla List
Cc: 	purplewax-at-juno-dot-com
Subject: 	Re: need fast tesla help PLEASE

On Sun, 7 Dec 1997, Tesla List wrote:

> From: 	Buckshot[SMTP:purplewax-at-juno-dot-com]
> Reply To: 	potato-at-rose-dot-net
> Sent: 	Sunday, December 07, 1997 4:40 PM
> To: 	tesla-at-pupman-dot-com
> Subject: 	need fast tesla help PLEASE
> Hi,
> I've just built a tesla coil powered by a 10kV transformer for a science
> project and just for interest.  Right now  it is only producing sparks
> of  about 3 inches.  I'm not sure if the
> primary and seconday coils are quite right.  My secondary coil is wound
> around 2.5 inch pvc pipe with magnet wire and is 24 inches high. 

Your secondary should be no more than about 12" long for something that is
2.5" in diameter.  This is an aspect ratio of 1:5, but somewhere between
1:4 and 1:5 for a coil of this size is better.

What size wire (gauge) are you using on this secondary?  I'd recommend
something around 26 to 24 gauge.

> The
> output terminal is a small, simple brass cap.   Is that ok? 

This is ok, but you could do better with a larger terminal to increase
voltage buildup before spark break out.  However, I'd suggest leaving your
small terminal on at first until you get the thing working well again.

>  My primary
> coil is made out of #12 copper wire and I'm not sure at what radius and
> height to wind it.  Right now it is wrapped pretty much right next to
> the secondary coil and goes most of the way up it. I don't think thats
> right.

Yeow!  No, you should have a dish shaped or flat spiral primary.  I'd
suggest using the dish shape, with about a 30 degree banking.  Of course a
flat primary is easier to build.  

If you are going to use a solenoidal primary, you shouldn't have it quite
so long.  The problem is that the voltage of the secondary is quite high
and will likely break down the insulation and spark to the primary.  This
will quickly fry the secondary, and also damage the capacitor.

Do you know about tuning?  What kind of capacitor are you using?  What's
it's value?  How much current can your 10000v power supply provide?


> Could you PLEASE help me. I just can't figure out whats wrong.
> Thanks a bunch,
>             Will Cross
>             potato-at-rose-dot-net

Chip Atkinson; Xi Graphics 1801 Broadway, Denver CO 80202
(303)298-7478voice (303)298-1406fax (800)946-7433sales