[Prev][Next][Index][Thread]

Re: Bipolar coil

At 05:11 PM 3/2/00 -0700, you wrote:
>Original Poster: Parpp807-at-aol-dot-com 
>
>Hi all,
>Can someone please give me info on the winding of the  secondary for my 
>centerfed
>bipolar coil. I think I read that the secondary should be wound in
>two sections connected by just a single turn of wire and it should be driven 
>by a 
>segmented primary. Can someone please help me on this? I posted on this same
>subject a week or two ago but I received no response.  :-((
>
>Cheers,
>Ralph Zekelman

The second coil I ever built was the large bipolar coil in R.A. Ford's
"Tesla Coil Secrets". The secondary was 12" in diameter and 48" long.
(sonotube) The primary was 24" in diameter (10-turn helix) and 12" wide. I
got good 18" streamers out of each end running an asynchronous rotary gap
on a 12kV, 30mA neon transformer and a salt-water capacitor. I know now
that the system was mis-tuned, and could easily have gone up to 24"
discharges on each end (and maybe more :) with info garnered from this list :)
I wound the secondary all in one winding, one end to the other, just like
an ordinary (monopolar?, unipolar? ;) secondary. Covering the interior
2/3rds of the secondary (approx.) were several layers of HDPE sheeting to
prevent flashover. The secondary wasn't grounded, and neither was the
primary. The whole system just floated (if I remember right.)
I moved the primary back and forth on the secondary until I got the best
output. I'm assuming, at that point, that the primary was centered on the
secondary.
My particular belief about bipolar coils goes along with the need for a
good ground in an ordinary coil. Basically, as far as I see it, each half
of the bipolar secondary "sees" a very good reflection of itself
(energy/power-wise), and because of this, oscillates well. A good ground
allows the same thing in a non-bipolar coil. (The systems sees a clear
reflection of itself in the ground.) That's why a counterpoise will work on
a small coil too. As long as there's a way for the coil to see a clear
reflection of itself, there will be much great efficiency in total output.
But it's just s theory ;)
Hope this helps,
Dan