Re: Secondary wire & insulation

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;

> Alfred, are you suggesting bare copper wire?

I have considdered bare wire on the grounds that a Tesla coil's ratio
of transforation is dependant on the ration of primary to secondary
capacitance and the highest voltages would be with the lowest 
possible capacitance on the secondary. The only catch is with bare 
wire the coronal leakage would outweigh any possible advantage.

> What kind of wire has everyone had the best results with? - I am
> assuming mag wire.

I don't know how many people have tried comparing otherwise identical
secondaries made of enamel and double cotton coated wire but I have 
and the coils wound with the double cotton coated wire performed much 
better than otherwise identical coils wound with enamel wire. They
yield longer and fatter sparks.

> I thought Tesla coils needed a good number of turns/inch and to be
> tightly wound. The use of insulated wire other than mag wire seems
> to go against this. Would appreciate any clarifications.

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 


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