Re: Secondary resonant frequency vs. Skin Effect

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

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


In classic pri-sec Tesla oscillators, in the sec circuit, the inductance
ratio is more important than Q factor.

With magnifier design the first sec coil (pri-sec system) must have a very
high Q factor.  The third, or resonator coil, does not require hi-Q.

Rich Hull and his group have proved this when they drive a closewound small
dia. wire design to 13 ft. long sparks from a resonator coil only 30 inches
long.

All of our classic coils routinely contain 800 to 1400 turns on the sec
inductor.

The correct design is easy.  As an example, let's say you have a 10 inch
dia. sec coilform.  Using an efficient 4.5:1 height to dia ratio, this
produces a winding length of 45 inches.  Next, divide the winding length, 45
inches, by 1,200. This will give you the dia. size of the wire required.
Use a wire table to look up the matching dia. and you have the correct (and
highly efficient) wire AWG.

Wind your sec coil with heavy armored polythermalize wire, install two
baffles of 1/4 inch acrylic approx 5 inches down on each end, top with a
toroid that has a major dia to coilform dia. of approx 2:1 or greater.

Measure the resonant freq with toroid in place.  Use the largest cap you can
(most energy) to match approx 8-14 pri turns.  Match the xmfr to the cap ---
keep the cap value approx 1.5 times the  resonant match value.

You will be rewarded with an efficient coil with very long sparks as
compared to it's overall height.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913

 > I am new to the list, but jus  twanted to warn of the low frequency which
 > can be typical of a large coil. I built my first coil 28 years ago. It was
 > 20" diameter x 48" and easily produced a 50-60" discharge. The resonant
 > frequency was 278Khz. This is actually a very low frequency and "skin
 > effect" does not apply at these low freqencies. In my opinion it is the Q
 > of the secondary that produces the high voltage rather than a turns ratio.
 > At the time I should have focused on producing the highest Q possible
 > rather than having a large number of turns (apprx 560 per memory). Anyway,
 > I was accidentally hit by the main streamer with only one or two snaps,
but
 > it nearly killed me since the discharge went through my body rather than
 > over the surface (as it would if the frequency were much higher).
 > I know many of you out there are very experienced.. but for anyone coming
 > into this with limited experience that one must be very careful. These
 > machines can toast you. I'm passing this on for  what its worth .
 >