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RE: Small coil ideas? warning %-at-!



Gary,
Warning !!
Your low side Sec wired to Pri connected to an AC powered OBIT sounds
dangerous, 
 and should be avoided by the new (& all) coiler(s).

Use a low Sec to earth ground (NO connection to AC Xfmr Sec). 
No impact to performance, but will make it safer,
 especially if you often allow Sec discharge to your finger ! 

The reason your finger feels nothing: there is too little capacitance
 in your little topload to store enough current to cross sensing threshold
 (and the high rep rate 120 bps tends to anesthetize the nerves).
 Try a much larger toroid and repeat the finger experiment w/Sec low to
earth gnd.

Regards, Dale

-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Tuesday, December 14, 1999 4:50 PM
To: tesla-at-pupman-dot-com
Subject: Re: Small coil ideas?????


Original Poster: gweaver <gweaver-at-earthlink-dot-net> 

What do you have to work with in Mexico?

Can you get your hands on a high voltage transformer?

Here are the specs on a small Tesla Coil that I built. 

Transformer is a furnace ignitor transformer 6K 20ma.

Capacitor is .005 uf made with 2 sheets of aluminum foil 6" wide x 13.5"
long rolled up with 9 sheets of .006 mil polyethylene between the aluminum
foil. Voltage rating is 20K. Oil filled inside of a 2" diameter pvc pipe.

Spark gap is 4 pieces of copper tubing 3/4" dia x 2" long .025" gap between
each tube.  3 gaps.

Primary coil is 5 turns of 12 guage solid copper insulated house wire flat
wound 1/2" betweem turns Tapped at turn 5.

Secondary coil is 1.5" diameter pvc pipe wound with #28 wire 7" long.

Top load is a 2" diameter brass door knob.

The bottom end of the secondary coil is connected to the inside turn of the
primary coil with NO ground wire.  No safety gap. NO strike rail. NO chokes.
NO cooling fan.  Spark gap is connected in parallel across the High Voltage
terminals of the transformer.  Capacitor and primary coil are connected in
series and both are connected in parallel with the High Voltage terminals of
the transformer.

The top load tends to produce 5 sparks about 4" long all the time that
radiate outward and rotate counter clockwise around the top load. If you
give the discharge sparks a target they are purple blue sparks 8" long in
very dry weather.  

One thing that is interesting about the discharge sparks is, they will not
shock you if you touch them with your finger.  It makes a very tiny warm
place on your finger where the spark strikes your finger but you can not
feel a shock.

Hope this helps.  This might give you some ideas for building your own coil.

Gary Weaver


At 05:35 PM 12/13/99 -0700, you wrote:
>Original Poster: Rodolfo Sanchez <ecoener-at-prodigy-dot-net.mx> 
>
>Im want to built a very small Tesla coil, tellme how can i do this
> 
>Regards 
> 
>Rodolfo Sanchez from Mexico
> 
> 
>
>
>
>