Re: Secondary size

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 1/15/04 7:32:09 AM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>Thank you for the input.
>So why can a small dia secondary handle only so much power?
>For example your 6" coil designed for 15KV 120mA what is happening that
>causes the near destruction running it at 600mA 15KV?
>Not that I need exact formula's but what is happening?
>
>And thanx never really understood why some used a double toroid on the
>top.
>Ill look more into that next I guess.
>So you might see some questions related to that soon.
>
>thanx
>
>Luke Galyan
>Bluu-at-cox-dot-net


Luke,

I base that statement on the observation of intense blue corona completely 
enveloping the secondary with occasional streamers breaking out from the 
secondary along its length and thin streamers traveling from the bottom of 
the toroid down through the corona toward the primary.  Believe me, 
standing about 20 feet away, when this coil is running at full power, you 
wonder when it is going to go up in smoke.  I observed a similar thing with 
my 3" coil when I was experimenting with my first synchronous rotary 
gap.  I think the coupling was too tight on this coil.  The secondary 
shorted in a couple of places from turn to turn and sparks discharging from 
the lower one third of the coil (to the primary) caused burn spots in the 
windings.  I had to rebuild that coil.

I could probably run higher power levels on the 6" coil if I backed off on 
the coupling.  But I am guessing I would not achieve any longer sparks than 
at present.

I would think that any Tesla coil system can be overpowered to 
destruction.  Where that limit is depends on the physical geometry of the 
thing and the level of coupling.  I can't tell you how to determine this 
without experimentation.  By the way, I think my 6" coil coupling is about 
.18.  Also, I am not aware of any other coiler applying that much power to 
a 6" coil, nor of achieving 104" sparks with a 6" coil.  I think it is 
"living on the edge".

Ed Sonderman