Re: Secondary wire & insulation

Subject:     Re: Secondary wire & insulation
      Date:  Fri, 06 Jun 1997 15:01:29 -0400
      From:  "Edward J. Wingate" <ewing7-at-frontiernet-dot-net>
        To:  Tesla List <tesla-at-pupman-dot-com>
References:  1

Tesla List wrote:
> Subject:  Re: Secondary wire & insulation
>   Date:   Fri, 6 Jun 1997 03:34:57 +0500
>   From:  "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
>     To:  Tesla List <tesla-at-pupman-dot-com>
> On Wed, 04 Jun 1997 08:24:04 Eastern Daylight Time Mad Coile{
> <ts5815-at-devrycols.edu> wrote;


I beg to differ with you. I have an 18" dia. classic coil wound with #18
thhn machine tool wire to a winding length of slightly over 3' which
will produce 8 to 9 ft arcs. This is almost 3 times the coil length in
spark output, which I consider *fairly* efficient. This coil is *not*
space wound and has never ever broken down between turns in the 6 years
it has been in operation.

I have obtained 5 times the coil length in spark output( 10 to 12 ft)
with some of the extra coils I have used on my magnifier system. These
extra coils are tight wound with plain old #18 heavy polythermalize
magnet wire and don't break down between turns either. I space wound my
first coil with magnet wire, but later learned that it isn't necessary
or even desireable on a properly tuned system. In fact you lose precious
inductance by space winding!

If you would like to see for yourself:


None of the pictured coils are space wound.

Richard Hull has achieved 10+ times the coil length with an extra coil
that is a mere 4" X 12" and is *tight wound* with #30 Kynar wire wrap
wire!! That one doesn't break down between turns either but it sure gets

I do, however, agree with you that many of the older articles were
incorrect in telling folks to use thousands of turns of fine wire. Now
that's an invitation for turn to turn breakdown. Fewer turns of heavy
wire have worked best for me over the years!

Safe coiling,

Ed Wingate

 >Firstly if your coils are efficient you will need to space your turns
> no matter what kind of insulation you use or your secondary will
> break down between turns! Secondly the idea that a Tesla coil
> requires lots of turns is a kind of misnomer that seeed to be
> perpratrated by the older electronics magazines that portraied Tesla
> coils as long and thin with thousands of turns of fine wire - BAD
> DESIGN! Those designs were poor performers at best, they had too much
> resistive losses and were designed wrong from the start. I think the
> idea that a Tesla coil required lots of turns was based on most
> peoples experience with low frequency transformers where the ratio of
> transformation is directly proportional to the turns ration thus for
> a large secondary voltage you needed a lot of turns. Not so in a
> tesla coil, a tesla coil's ratio of transformation is primarily
> determined by the ratio of primary to secondary capacitance or
> inductance, so you can have a Tesla coil with say 5 turns on the
> primary and 100 turns on the secondary and have a large primary
> capacitance and have a ratio of transformation much higher than the
> 20:1 you would expect from a low frequency transformer.
> Sorry if any words are missing m's but my m key got the stickies and
> I don't plan on disassembling my keyboard to fix it until the
> weekend!