* Originally By: Mconway-at-deepthnk.kiwi.gen (Mark Conway)
 * Originally To: Richard Quick
 * Originally Re: TESLA COILS
            Date: 17 Jun 1995 18:18:47 GMT
    Organization: Deep Thought NZ, Auckland, NZ

Hi Richard,

Thought I'd drop you another note to say how I'm getting on with my coil - I
havent had a chance to do a lot on it lately as this is a real busy time of
year for me.

I have finished my primary coil- it is 15 turns of approx half inch diameter
copper tubing wound on plexiglas supports. It looks really good. The
secondary and the toroid are finished as well - when I put the
secondary,toroid and primary together the total setup looks really evil- you
can almost feel the power coming out of it.

I have made 2 gaps like in your video out of 6 inch diameter pipe and copper
cylinders mounted inside. Both gaps are supported by wooden stands just like
in your video. I have also finished the safety gap and the suppression caps.
The suppression caps are made out of glass plates (approx 7 inch square with
8 pieces of glass in each capacitor) and copper sheet. They stand vertically
in a tupperware container each and both are covered by mineral oil. I have to
admit that I am a bit worried about them as when I made them I covered the
glass plate with glue and then put on the copper plate etc, little bubbles of
gas (glue fumes) were left in between the plate and copper. Since the glue I
used has flammable vapours I am worried that when corona goes thru the glass
it may cause the vapours to light and because there is no way for them to get
out the glass may explode. The bubbles in the cap are only small and maybe
even if they do ignite hopefully there wont be enough gas in them for the
pressure to build up very much. I should have only put glue on the outside of
the plates to hold them together - I'll know much better next time. Do you
think that I should rebuild the caps? I guess another disadvantage of the way
I have made them is that the mineral oil will not be able to get between the
glass and copper sheet to cool them down.

Good news on the main capacitor front - I have just bought some poly sheet
like you use in your caps. It is 1.5 mm thick and comes in sheets of 2 metres
by 1 metre.  It took me ages to find a firm that sold the stuff. I had been
building a cap out of poly sheet and aluminium foil but it had been going
very slowly. Since I already have the cap tanks made it will take me much
less time to make a cylindrical cap ( I will make 4 of them and connect them
in series parallel). Instead of aluminium flashing I will have to use
aluminium cooking foil as no one in NZ sells the stuff that you use for your

One thing that concerns me a bit is the protection of my neon power supply -
I have two 60 mA 15 kv neons.  I have two toroids to protect them but I
recently read an article on Tesla coils which says not to use toroids but
instead to use ferrite rods as toroids since they are closed will saturate as
they complete the magnetic circuit. I notice that you and everyone else that
makes big performance coils seem to use toroids for protection - are toroids
really better than using ferrite rods?  If my coil gives good performance I
guess I'll have to try and find  a power pig to run it reliably.

One last question! In your power controller you use relays to provide
isolation from the high voltage circiutry. Do you use them to connect power
to the neons and how necessary do you think they are - I think from your
video, when you were doing most of your experiments you didnt use the relays
at all? Do you use relays with your power pig as well? 


Best Regards,

-- Mark
       _/_/_/   _/_/_/_/       Mark Conway
      _/    _/    _/          Deep Thought BBS, Auckland, New Zealand
     _/    _/    _/          A FirstClass(tm) Macintosh GUI BBS
    _/_/_/      _/          Internet: mconway-at-deepthnk.kiwi.gen.nz