FW: Still getting strange / poor results.

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

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>


Simon -

I entered your coil specs in the JHCTES Ver 3.2 TC computer program at

   http://home.att-dot-net/~couturejh

with the following results. It is obvious why you are having trouble with
your coil using a 6.27 nF primary capacitor. The tuning is not correct as
you need 18.01 primary turns. However, with a 10 nF cap you will only need
14.26 pri turns to be in tune.

I entered the following

Pri cap            .00627 uf
Avg Radius        8.13
Width             8.00

Sec Radius        3.00
    Turns       862.00
    TPI          34.48 = 862/25
    Wire         22.00 (not used in this calc)
Sec Term         26 pf

Some Outputs
Oper Freq       169.84 Khz
Pri turns        18.01
    Ind         140.06 uh

Sec Ind           24.14 mh
    Tot cap       36.38 pf

If you substitute a .01 uf pri cap you will get 14.26 pri turns and 87.82 uh
pri inductance when you press "recalculate".

You can get other output parameters by going to the program and running it
on line. You can make dozens of other changes and the computer will do all
the calcs to keep the system in tune when you press recalculate. In other
words the equation
      LpCp = LsCs
will always be balanced keeping the system in tune.

It is obvious that the "sec terminal pf" input will affect the operating
frequency. At the design stage this is only an estimate because it is
difficult and may be impossible to know how the terminal cap will change
when placed on the sec coil. Terry's E-Tesla6 program is an attempt to solve
this difficult problem. I am estimating that your two toroids will give you
about 26 pf when placed on your sec coil. This will give an operating
frequency of about 169.84 Khz and both the sec and pri circuits will be
tuned to this freq by the computer.

It may be that the only way to find the true sec terminal capacitance is by
testing the finished coil for the actual operating frequency. With this
information you can then solve for the true sec terminal capacity. This can
also be easily done with the JHCTES program by adjusting the "sec terminal
pf" input until the actual operating frequency appears in the output. This
will also make the other outputs more accurate. This would be a good test
for this coil when it is completed.

Note that when you change the Pri Avg Rad you change the Pri to Sec distance
in the outputs. Note also when you change the Pri Width you change the c/c
spacing in the outputs. Other output changes are also made automatically.

The secondary inputs determine the operating frequency and the computer
finds the primary turns for you to ensure the primary circuit is in tune
with the secondary circuit at all times. When you increase the Pri cap the
Pri turns will be decreased to the proper number of turns by the computer.

If you have any questions please let me know.

John Couture

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

-----Original Message-----
From: John H. Couture [mailto:couturejh-at-worldnet.att-dot-net]
Sent: Saturday, January 27, 2001 3:49 PM
To: Tesla list
Subject: RE: Still getting strange / poor results.

Simon -

Try entering your coil's parameters into the JHCTES Ver 3.2 computer program
to find the primary turns you need. This program can be run on line or
downloaded (Ver 3.1) at my web site

    Http://home.att-dot-net/~couturejh

I would be interested in what you find.

John Couture

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


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, January 27, 2001 3:09 PM
To: tesla-at-pupman-dot-com
Subject: Still getting strange / poor results.


Original poster: "Simon Yorkston by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <quantumx-at-ozemail-dot-com.au>

Hi all.
Well, I rewound my secondary, and hooked it up to the coil, and fired up,
and to be honest, I didn't get much improvment- [maybe about 1-2" longer].
The coupling was a little loose, so I rewound it closer. Then the strange
things started happening [again]. I could only just get breakout if I tapped
the primary as far as it would go - 17+ turns.

What is going on with this coil to make it defy calculations, and give poor
results? I've rebuilt everything on this coil.
The only thing that is left is: the transformer [doesn't seem to be
dead..when they die, do they lose perfomance, or do they just die w/ smoke
etc]
                                             : the protection filter. [As
per Terry's, but with a MMR of 4x3K 11W resistors on each hot]

I have ordered some more capacitors to boost the tank up from 0.0062 to
~0.01; IS that what will make a BIG difference?

Thanks all.
Simon