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

Re: Toroid = shorted turn ?



Tesla List wrote:

> Original Poster: "Payne, Will E" <will.e.payne-at-lmco-dot-com>
>
> Most large top loads and especially toroids I have seen are conductive all
> the way 'round, which forms a shorted turn above the top of the coil.  The
> induced EMF would create a repulsive field cancelling the ringup field, in
> effect "shading" the upper end of the secondary and wasting energy.
>
> Some coilers believe this is not a significant effect, but I remain
> skeptical.  Coil behavior is pretty sensitive to the spacing between the top
> winding and the toroid, although I realize other effects are also at work
> here.  I tried to insulate the joints of my stovepipe toroid and connect
> each section together at the center.  The voltage at the joints would be no
> more than a hundred volts, I think.  Since my joint insulation did not
> survive the assembly process, and I have plenty of more important things to
> optimize, my experiment may have to wait for the next toroid.  However, I
> would like to hear from anyone else who has investigated this.
>
> Will

  A closed toroid is indeed a shorted turn and does negate the top turns to
the
degree that it is coupled to them.  That is why I always over wind and
throw the
last 4" or so of my coil to the dogs.  The good part is that the power loss is
minimal if the assembly is mounted and used correctly.  Also the voltage
gradient on the turns dies off to nothing near the top turn and the
electrostatic shielding more than compensates for a small percentage of the
input power lost here.  If I opened the toroid the voltage on the top turns
would still die off, but the powerloss would be minimal and undoubtedly
un-noticable in the ouput.  This I have tried numerous times and proven to my
satifaction, without math or coupling calcs but by the doing.  If I can't
see a
whit of difference in the spark on two different runs split toroid vs. closed
ring toroid at the same input power, I move on.

 I am after spark and not efficiency.  I am not powering anything with the
output 24 hours per day.  I run it for .00000000000682956% of my liftime.
If it
needs more watts to make longer spark, the power compnay and I have a deal
whereby they agree to supply me with all the power I can afford to pay for.  I
get long sparks and they are pretty dog gone long for the power I put in.
If it
is a cost of 5 or 10% of my input power to get significantly longer sparks,
I'll
pay up and to hell with the engineering.  If I was building this for a
customer
who ran the thing 50% of a 24 hour day and powered a manufacturing process
with
the output, I would be much more concerned.  He is just as concerned with cost
of operation as much as functionality.

If I lose 10% of my entire run energy in, say, a 3 minute long run at 7KW.
That
makes for .035kwh thrown away.  Virginia power bills me for about 8.5
cents/kwhr  that is 0.29 cents that I just threw in the trash.  Thus I blow a
penny on lost energy for 9 minutes of fun in the sun with my coil.  On maggey
#11E, the way I run it,  that is a months worth of operational loss assuming I
swallow a full 10% loss due to the toroid (which I don't believe in the first
place).  I'll pony up the solid zinc, copper clad penny any time over
sawing up
my beautiful  spun toroids.

Richard Hull