RE: Magnifer vs. Tesla Coil

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

Original poster: "John H. Couture" <couturejh-at-mgte-dot-com> 


Dr. Resonance, All -

It has been a very long time since I have worked with current limiting
reactors. There is a big difference between reactors for utilities and
reactors for Tesla coils. Reactors for utilities are for one shot short
circuits while for Tesla coils the short circuits are continuous.
Fortunately for Tesla coils the short circuit currents are much smaller. The
short circuit currents for utilities are sometimes so large that circuit
breakers are not available to interrupt them. This is when current limiting
reactors come in handy.

In general the reactors for Tesla coils are selected for best operation
using past experience. As Dr. R. pointed out the biggest problem is
overheating because of the continuous operation. This is one example where
overdesign is desirable. The reactor controls the amount of input energy
going into the TC. This energy must be known to properly compare Tesla
coils.

Several years ago I did some testing of some small coil magnifiers. The test
results indicated that there was no gain in spark length for magnifiers
compared to the classical TC when small coils were used. However, I noticed
that the bare #12 AWG wire I was using to connect the third coil produced a
lot of corona. I never got around to doing more tests with copper tubing to
reduce the corona and determine if that would give a longer spark with the
magnifier setup.

  If the magnifier design info that is available today was available back
then I certainly would have done more testing. At that time magnifier design
information was almost non existent and I was working in the dark. Tesla's
writings were not very helpful. I was aware of R. Hull's and other coiler's
magnifier work which looked promising but these tests were based on sketchy
energy input data which made comparisons questionable. Even today the
magnifier vs Tesla coil comparison would require reliable input energy data
to make a correct decision as to which system is more efficient.

John Couture

-------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, November 14, 2003 9:55 AM
To: tesla-at-pupman-dot-com
Subject: Re: Magnifer vs. Tesla Coil


Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>


These claims need further investigation.  A pole xmfr is capable of
providing much more current for very short periods of time, especially when
recharging cap banks.

If you run a pole xmfr with a current limiting device the pole xmfr will not
draw a complete sinusoidal current curve.  It usually is distorted somewhat
as the xmfr and reactance hit short periods of saturation.  It's a fast
event and requires a storage scope to monitor.

I became aware of this even by running a 130 turn current reactor set with a
climbing arc at 25 Amperes.  The reactor was wound with 12 AWG wire and fan
cooled.

After 2 minutes of operation the reactor was smoking hot.  It was handling a
lot more current as the pole xmfr hit saturation peaks.  The ammeter was
bouncing in the 35-45 Amp range.  The TC output was very high and the
"average indicated" power was around 35 Amps.

Now, we use 9 AWG on all of our reactors running at 25-30 Amperes.

John Couture first brought this to my attention approx 15 years ago when I
visited him in San
  Diego.  Perhaps he could comment on this phenomonea a bit
more as he is a retired power electrical engineer from a large electrical
provider out east.

Magnifiers do gain especially in the area of energy transfer.  With their
tighter coeff. of coupling more energy can be transmitted from pri to sec.
A double resonant transfer provides nearly 90-95% on the second max. peak
whereas a standard TC operates closer to 70-75% max at 0.2 coeff. coupling.
If not moe voltage they offer more current output which makes the sparks a
lot brighter.  Ed Wingate's coil is a very good example of this effect.  His
output sparks were very bright when captured on film as compared to a normal
classic TC.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913

  >
  > Richard Hull stated that magnifiers have obvious advantages over the
  > conventional Tesla coil. Indeed, his magnifier impressed us all with its
  > efficiency. I was there and video taped it in action. 11 feet of spark
from
  > 5 kw (or was it kva?) input power.  John Freau made a claim once (if I am
  > not mistaken) that he has never seen a magnifier out perform a
conventional
  > Tesla coil watt for watt. At first, I thought that this couldn't be,
since
  > this magnifier that Richard Hull put together just had to be the most
  > efficient thing out there.  Then one day, while looking at Bill Wysock's
  > website, http://www.ttr-dot-com/model9_page2.htm he has images of the super
  > model nine coil producing 17 feet of spark at a stated 5kva input. So is
the
  > magnifier more efficient than a conventional coil? Yes, you can get many
  > times the secondary length in spark output that would not be possible
with
a
  > conventional coil. It will be interesting to see where the magnifiers go
to
  > with renewed interest, and new heads and hands pushing the designs
further
  > on.
  >      I think that Richard said that the primary and the capacitor should
  > resonate at 1/8 wave of the secondary coil. That's where voltage and
current
  > are both at 70% of their maximum. This could be thought of as a signal
  > generator to base feed the third coil, which should have a huge topload
on
  > it. If I remember correctly, the frequency off the top of the secondary
  > should be the 1/4 wave frequency that the third coil resonates at.
  > The 1/8 wave configuration makes sense to me because otherwise it would
be
  > difficult to manage all the corona if it were set to run at 1/4 wave.
  > Richard even stated that you could build the coil to run at 1/16 wave,
where
  > the voltage gain would not be great but the current from the secondary
would
  > be terrific. Again, if this frequency is fed to the base of the third
coil
  > and it is 1/4 the wavelength of that third coil, it is supposed to work.
  > I have not built one as of yet. What do the other maggie builders think?
  >
  > Dave G.
  >
  >
  >
  > ----- Original Message -----
  > From: Tesla list <tesla-at-pupman-dot-com>
  > To: <tesla-at-pupman-dot-com>
  > Sent: Tuesday, November 11, 2003 7:08 PM
  > Subject: RE: Magnifer vs. Tesla Coil
  >
  >
  >  > Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com>
  >  >
  >  >
  >  > This is a heavily debated topic.
  >  >
  >  >  >From what i've seen so far, it seems that magnifiers are much more
  >  > efficient right off the bat compared to the
  >  > average conventional coil.  The best performance I've seen to date is
a
  >  > video of Richard Hull's Magnifier 11 or something like that.  The free
  >  > resonator coil is 4" diameter x 13" in length and puts out over 10
foot
  >  > arcs using a relatively
  >  > low power (5kW?)
  >  >
  >  > However, magnifiers are much different beasts and have their own set
of
  >  > complexities.  For example, the complexity of building a fast
quenching
  >  > spark gap (usually rotary / series hybrid) may well be the crux of the
  >  > entire design and may
  >  > not outweigh the benefits of a magnifier.
  >  >
  >  > I don't have any personal experience with magnifiers yet as I am
  >  > building my first, but I definitely think it is worth
  >  > it to explore the tesla magnifying transmitter once you have already
  >  > built some conventional coils.
  >  >
  >  > Dan
  >  >
  >  >
  >  >  > I would like to know the advantage of a Magnifer vs. a Tesla
  >  >  > Coil. I would
  >  >  > like to build a magnifer as my next project.
  >  >  >
  >  >  > Thanks,
  >  >  >
  >  >  >
  >  >  > Paul S. Marshall
  >  >  >