Re: need fast tesla help PLEASE

From: 	D.C. Cox[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: 	Monday, December 08, 1997 12:10 AM
To: 	Tesla List
Subject: 	Re: need fast tesla help PLEASE

to: Will

You have a bunch of problems.  You didn't say what size your transformer
was (current is more important than voltage) and you didn't say what value
your cap was so it's rough to guess where you are with your pri to sec
resonance.  A typical 10 KV oil burner ignition transformer (OBIT) produces
about 20 ma of current and will match well with a .003 or .004 MFD
capacitor.  The primary coil is wound in a flat spiral usually about 1 inch
below the start of the secondary and 1 1/2 inches away horizontally.  A
"test" winding with 12 AWG wire is usually required to find the correct
primary tap to match your primary capacitor and secondary terminal to hit
the best resonance.  Start with about 20 turns and then tap down as
necessary.  You will probably end up with 12-16 total turns but it's nice
to know you have the extra turns at least for your test.  A small 2 inch
dia toroid or 2 inch dia ball like a copper plumbing float will work ok for
a terminal on this small coil.  Your sec height to diameter ratio should be
around 4:1 or 5:1 which suggests a finished height of around 11-12 inches
tall. If possible use a variac to control the high voltage transformer so
you can conduct your tuning experiments at around 30% power.  Don't apply
full power until you are in tune or you could damage your cap or xmfr.  


> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-poodle.pupman-dot-com>
> Subject: need fast tesla help PLEASE
> Date: Sunday, December 07, 1997 9:52 PM
> 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. The
> output terminal is a small, simple brass cap.   Is that ok?  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.
> Could you PLEASE help me. I just can't figure out whats wrong.
> Thanks a bunch,
>             Will Cross
>             potato-at-rose-dot-net