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Re: Toroids
From: FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
Sent: Tuesday, September 02, 1997 3:09 AM
To: tesla-at-pupman-dot-com
Subject: Re: Toroids
In a message dated 97-09-02 04:14:18 EDT, you write:
<< >
> Been reading the discussion on toroid size "More Research". Is there sort
> of a rule of thumb on the size a toroid should be, in a small system, with
> regard to the size of the secondary coil? This would be sort of a
starting
> size, as I gather the toroid size can increase to large proportions with
> the application of more power.
>>
Dale, All,
For neon sign tranny systems, for a 12kV, 30ma, a 5" x 20" toroid
seems to be about the max useable size. For a 15kV, 60ma,
6" x 26" seems good. In both cases, my secondary is 6 1/2" dia,
x 24" long. But if my secondary was 4" dia, I would still use the
same sized toroids. The needed toroid size seems more related
to power input, than to secondary size. The above sizes assume
resonant charging of the caps. If resonant charging is not used...
the toroids will have to be much smaller. I'm presently building a
small system for a friend, it will use a 7.5kV, 30ma tranny, and
only a .00125uF cap which is much too small for resonant
charging. Thus, I use a very small 5" dia toroid, and spark length is
about 9". I find, in general, that spark length is usually 2 to 4 times
the toroid diameter for most systems, for greatest efficiency. The
sparks can be pushed farther...but power will have to be poured in.
John Freau