>To make a comment on trifilars coupled to alternator three phase, then the

windings would be producing magnetic cancellation.

This is what we want isn't it? What is a longitudinal wave? I'm not sure

what will happen just yet, but if I don't try it I'll never know.

There are a couple ways to finish a wye coil. One is to keep all three

leads together, the other is to terminate them at 120 degrees apart from

each other. When they are terminated at 120 degrees, the inductance on each

lead is slightly different from the others. On my wye coil I have 6.20mH,

6.23mH, and 6.25mH. The slight difference in inductance may either setup a

rotating magnetic field, or result in a dud. I'm not sure how that will

work just yet either.

>It is good that you have also noted the reduction in resonant frequency

with spirals, which was ~ 4/1 on the 4 wind model I made.

This is still a mystery to me. Tesla was adamant all through his life that

quarterwave is the resonant frequency of the coil. Tesla mostly worked with

flat spirals. I know the guys on pupman who routinely work with cylinder

coils say quarterwave is not necessarily the way to go to get big sparks.

Of course Tesla only tried to get big sparks at Colorado Springs as a

photography thing to dazzle his potential investors. His real aim was in

setting up resonant fields in the earth and tuning for maximum power

transmission. In his patents, Tesla is partial to the flat spiral coil.

His Wardencliffe tower employed flat spiral coils for transmitting and

resonating the earth. He must have known something about flat spiral

secondaries that we have not yet discovered.

I believe this hidden knowledge is related to the odd characteristics of a

flat spiral secondary and one of those characteristics is that the measured

resonant frequency does not match the quarterwave, in fact it is about 1/4

as you noted. Further, the calculated inductance of the flat spiral

secondary is 1/3 the measured inductance for a single wind.

I find the ratio of 4/3 in another aspect of flat spiral secondaries. In

order to get the maximum inductance from a given length of wire, the average

radius should be 4/3 of the width of one side. I verified this

mathematically. I'll need to write a paper on this mathematical analysis

and post it. To get the maximum inductance for a given diameter, you would

wind the coil from the center out. This is why all Tesla's flat spirals are

wound from the center out. Where the 4/3 rule comes in handy is when

designing a flat spiral primary for a helical coil. The size of the flat

spiral primary should be calculated to the 4/3 rule and the diameter of the

solenoid coil should be based on the available space within the inner

diameter of the resulting flat spiral primary.

The world of flat spiral secondaries is loaded with easy to breach

frontiers. There will be many new discoveries in the coming years based on

these coils.

Dave

David Thomson

dave@... <mailto:dave@...>

-----Original Message-----

From: harvey norris [mailto:harvich@...]

Sent: Thursday, January 31, 2002 5:55 PM

To: reply@...

Cc: teslafy@yahoogroups.com

Subject: [teslafy] Re: Wye Coil

--- David Thomson <dave@...> wrote:> Hi Harvey,

http://www.tesla-coil-builder.com/FlatSpiralSecondaryTrifilar.htm.

>

> It has been brought to my attention that you are

> interested in a wye wound

> secondary. I produce these coils in flat spirals.

> It would be possible to

> wind a cylindrical coil in the same manner. I

> haven't yet tested the coil

> with 3 phase power, but I will as soon as I can find

> an automobile

> alternator I can rewire. I believe the flat spiral

> form of the wye coil

> will produce some unusual effects. I have already

> tested this coil in

> different ways with single phase power through a

> 15KV 60mA NST. You can see

> my journal at

>

EXCELLANT SITE!> I have also started a new group specifically for

Will be joining shortly.

> flat spiral secondaries.

> It is at http://groups.yahoo.com/group/spiralcoils/

>

> Dave

>

> David Thomson

> Volantis

> dave@...

>

To make a comment on trifilars coupled to alternator

three phase, then the windings would be producing

magnetic cancellation. It might be amusing to ground

them at distant triangulations to produce hf standing

waves in the earth. Then each trifilar winding would

have to act as a one ended condition sheme, with the

earth between the points as the wye connection. That

situation should prevent the expected large currents

that would be expected to occur if the wye assembly

were merely attached to the 3 phase alternator, in

which case, its impedance being mostly nullified might

be difficult to resonate from those alternator inputs.

If in fact it were possible to resonate windings of

this nature, it would mean employing huge capacitites.

However nothing is really known till you try it. Marc

Metlica is interested in trifilar secondaries, I will

forward your EXCELLENT web site to him.

It is good that you have also noted the reduction in

resonant frequency with spirals, which was ~ 4/1 on

the 4 wind model I made. I find it unusual that your

final tuning indicated the best action at the higher

frequency nearer to the quarter wavelength.

Sincerely HDN

=====

Tesla Research Group; Pioneering the Applications of Interphasal Resonances

http://groups.yahoo.com/group/teslafy/

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have made me wonder. I have a bipolar coil but connected the primary to

earth ground instead of the other side of the grounding secondary. I'm

going to try that and see what happens.

Dave

David Thomson

dave@... <mailto:dave@...>

-----Original Message-----

From: Mikael Bi [mailto:qtx_2000@...]

Sent: Saturday, February 02, 2002 4:33 PM

To: teslafy@yahoogroups.com

Subject: RE: [teslafy] Re: Wye Coil

yes thank you very much, so it is possible to make a

bipolar coil. so does it mean that if I want to make

work a coil say 24.7 Mhz about 10 feet long wire, that

would mean I would need and other 10 feet coil as a

ground, how would it be connected??

--- David Thomson <dave@...> a écrit :

<HR>

<html><body>

<tt>>Please explain me the concept of quarter wave

lenght..I know the<BR>

calculation of if, but I don"t understand the

concept behind.<BR>

<BR>

For all the years Nikola Tesla made high voltage

coils, he always found that<BR>

quarter wave length wires produced the best results

for him.<BR>

<BR>

To get the highest resonant rise of potential (highest

voltage,) it is<BR>

necessary for the impedance at the base of the coil,

where the secondary<BR>

meets the ground, to be zero. The coil best

suited for a zero ground<BR>

impedance is the quarter wave coil since the voltage

node is at ground (zero<BR>

volts.) From voltage node and upward is just

part of the wave, however.<BR>

There is also a wave portion equal to the upper wave,

from the ground down.<BR>

This downward wave portion is a mirror of the upward

wave portion.<BR>

<BR>

This is why Wardencliffe needed such an extensive

underground grounding<BR>

system. Tesla needed to easily sink 50 million

volts of negative potential<BR>

into the ground and just as easily project 50 million

volts of positive<BR>

potential into the atmosphere. He chose the

large flat spiral coils for his<BR>

primary and secondary coils. His secondary coil

also connected to other<BR>

spirals, free of mutual inductance with the

primary/secondary transformer<BR>

stage. The total wire length of all the spirals

above the secondary would<BR>

have been equal to one quarter of the wavelength had

he not had a top<BR>

capacitance. That large tower added enough

capacitance to the secondary<BR>

circuit that Tesla was able to use an odd multiple of

the quarter wave<BR>

length instead.<BR>

<BR>

But regardless of the size of the coil or the amount

of power put into it,<BR>

it is essential that the point where the wave passes

from atmosphere to<BR>

ground equals zero volts. Otherwise the system

is unbalanced and difficult<BR>

to bring into resonance.<BR>

<BR>

It's important to realize that the quarter wave

frequency is a general rule<BR>

for a secondary coil with no top capacitance (or very

little capacitance.)<BR>

As the top load is increased, the length of wire can

be reduced. Tesla made<BR>

sure the top load was sufficient that the wire length

was an odd multiple of<BR>

the quarter wave length. That is if you started

with a wire 300 feet long<BR>

in your Tesla coil. The same frequency can also

be resonated on a wire 100<BR>

feet long with the correct extra capacitance on the

terminal. In the 300<BR>

feet wire example, the wave is traveling not only the

300 feet through the<BR>

wire, but also 300 feet into the ground.

Traveling the full distance of 600<BR>

feet, the wave has traveled half of a cycle. It

then travels back up the<BR>

system to the top of the coil for a full 1200 feet of

distance for one full<BR>

cycle. Thus the wire in the coil is just 1/4 the

total distance the wave<BR>

will travel (or an odd multiple thereof.)<BR>

<BR>

This is why a good ground is essential for operating a

Tesla coil connected<BR>

to ground. You can also operate two identical

coils and use one to act as<BR>

the ground. So if you had a 300 feet long

secondary coil and built an<BR>

identical coil to use in place of the ground

connection, the wave will<BR>

travel its full cycle without use of a ground.

This is the theory behind a<BR>

bipolar coil. The total wire length in a bipolar

coil is half the<BR>

wavelength and the primary is situated in the middle

of the secondary. The<BR>

resonant frequency is calculated accordingly.<BR>

<BR>

In the bipolar coil it is easy to see why the voltage

needs to be zero at<BR>

the halfway point. If one coil were longer than

the other, then the system<BR>

can not resonate. The same holds true for a

grounded coil. If the voltage<BR>

node is not exactly at ground, then the system will

not fully resonate.<BR>

<BR>

I hope this helps.<BR>

<BR>

Dave<BR>

<BR>

David Thomson<BR>

dave@... <mailto:dave@...><BR>

<BR>

</tt>

<br>

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