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Re: Primary and Secondary winding direction



Original poster: "Peter Lawrence by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Peter.Lawrence-at-Eng.Sun-dot-com>

Alan,
     I have secondaries that are wound in both directions (my hand-wound ones
go one way and my lathe-wound ones go the other) and I have not observed any
difference.

I also took a conical primary that was too highly coupled because the cone
was too high an angle and turned it over and made it nearly flat, which
successfully reduced the coupling and therefore reduced the racing sparks
I was having, and other than the coupling effect, the reversed direction of 
the primary did not have any other effects. Output sparks were the same.

ICBWB, I'm pretty sure that the primary and secondary coils are 90-degrees 
out of phase during oscilation (not 180 as someone has suggested), the top
of the secondary will be at max volts as the primary has zero volts (max
current) across it, so it does not really matter what polarity the secondary
top is (winding direction will determine polarity at the top, relative to
polarity (inside verses outside of the spiral) of the primary) - because
180 degrees later the sec top polarity will be reversed but the primary
will be back at zero volts (max current) again. 

At least to me symmetry arguments are always convincing, IMHO the requirement
for winding direction is a myth.

-Pete Lawrence.

(ps, I think there are way to many myths in tesla coiling, I myself fell for
the "1/4 wave length secondary wire" myth, and ever since have been doubting
as much as possible everything I read, and try to verify things with my own
experiments as much as possible).


> Hello All,
> 
> Are there any rules governing the direction in which the primary coil and
> the secondary coil are wound?
> 
> I have read on the web that the primary and the secondary *must* be wound in
> the same direction. I think that this is due to: the current induced in the
> secondary coil
> makes a magnetic field that is the opposite of the primary magnetic field
> and so the magnetic fields mutually annihilate each other.
> I am not completely sure about this, I haven't sat down and done the math
> :-(
> 
> My assistant suggested that you just swap the leads to the primary coil,
> (the primary tap lead and the center connection lead.) However, the
> resonation is like AC so therefore it will not make much difference, the
> induced current in the secondary will still make an opposing field to the
> primary, as *both* magnetic fields have swapped polarity. Am I right?
> 
> Thanks heaps,
> 
> Alan Williams