Re: more Maggie qustions

to: Mike

The secondary driver coil is usually connected to ground.  The primary is
excited from your spark oscillator with a high break rate usually around
1000 PPS.  The coeff. of coupling is usually set to around 0.6 -- very
tight, so some PE insulation is usually incorporated between pri and sec
coils to prevent breakdown.

These breakdown problems can be avoided all together by making the primary -
sec driver a single coil with a very high Q factor.  Use a large diameter
form and use 1/2 inch OD copper tubing spacewound for the first 50-60 turns.
Splice some #4 or #6 AWG stranded directly to the top end of this tubing and
then closewind the rest of the coil -- usually around 200 turns.  The lower
end of both the oscillator and copper tubing is connected to a very good
ground.  The high end of the oscillator is tap-fed into a turn somewhere up
the copper tubing.  It acts like a giant autotransformer and gives you a
stepup to around 200-300 kV depending on your Q factor.

This is then fed to the lower part of your resonator coil.  The resonator
coil does not have to have a high Q factor that's why small gauge copper
wire such as #24 AWG works fine.  The driver coil must have a very high Q
(hence the copper tubing) to provide a very large drive current at the base
of the resonator coil.

The top of the driver can be fitted with some 2 inch OD copper tubing
soldered together in a large circle.  The bottom of the resonator coil can
also have a 2 inch OD copper tubing lower toroid.  Upper toroid is a very
large (usually around 600-800% larger than the resonator coilform) toroid
topload.  Use 2 inch as a "current conduit" from the top of the driver to
the base of the resonator.

A nice topload for the resonator is formed with a paid of 1/2 toroids.
Separate these two halves approx 4-5 feet and then roll some 1 inch square
mesh chicken wire into a cylinder and splice between your two toroid halves.
This gives a great amount of capacitance and is actually better than two
toroids because with two toroids the top unit tries to "shield" the upper
part of the lower unit, and vice versa.  Max capacitance with two toroids is
only 1.5 times the value of one toroid (assuming they are the same dia).
The extended cylinder method allows you to achieve a large amount of
capacitance and overcomes the "shielding" effect which is undesireable with
regard to the two toroids.

Carlos has some nice equations which are accurate design factors for



-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Tuesday, August 03, 1999 5:54 PM
Subject: more Maggie qustions

>Original Poster: Michael Tucknott <Michael.Tucknott-at-virgin-dot-net>
>Hi all
>This is to the Maggie builders on the list.
>Just two qustions.
>1-Is the secondary(driver coil)conected to ground?
>2-Does the secondary(driver coil)need a toroid if so
>  what size should I be aiming for.
>Cheers Mike Tucknott(In swindon home of the Honda civic)  ;-)
>If at first you don`t succeed......
>It must be someone else`s fault so
>Find them; Blame them; Make them pay