Re: Coiling problems

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hello Nir,

Tesla list wrote:

>Original poster: Nir Weingarten <nirzvi-at-yahoo-dot-com>
>Greetings all.
>
>My coil is a 90 cn. high PVC pipe seeled at both
>edges.
>Around the pipe there will be coiled 37. wire that
>ends in a discharge terminal witch is a iron ball
>about 5 cn. in radios. This coil has no capasitors and
>a 15,000 neon light tansformer that is powered by my
>220 v. 50 hrz. home network.
>
>Here are some of the questions:
>
>- Should there be a restriction on the amount of laps
>around the secondary coil?

No restriction on the number of turns, but there is a recommendation = 1000 
to 1500.
And single layer of course.

>- What kind of wire should I use for the primary coil
>(open wire, magnet wire...)?

Most anything will do, but if you can get your hands on copper tubing 
(refrigerator tubing would work great), then you can build a nice primary 
without insulation. This allows you to "tap" or connect the primary along 
it's length when your tuning the inductance.

>- where do I conect the Primary coil?

Here's a quick Ascii art schematic. View with fixed width font.

                                          " OOOOO "
                                              s
                                              s
  --------  -------------------| |---------   s
  |      |  |            |      C         |   s
  |      p  |            |                |   s
  =      p  s            o                p   s
AC   NST p  s NST     GAP             PRI p   s SEC
  =      p  s            o                p   s
  |      p  |            |                |   s
  |      |  |            |                |   |
  --------  -----------------------------------
  |                                           |
--- MAINS                                  ----- RF
/// GROUND                                 / / / GROUND



>- What in fact is a spark gap, what does it do, where
>and how do I put it together?

The spark gap is a high voltage switch. It is comprised of separated 
electrodes (nothing but air between them which serves as the insulator). 
When the voltage has reached the potential required to arc across the air 
gap, the switch is then closed. The air gap distance sets the voltage 
potential required to arc the gap. It should be set to your NST's gap 
arcing ability. Check NSTand sparkgap out of the circuit and set the 
sparkgap distance to the NST's maximum arcing ability. Your air gap is then 
set.

The sparkgap electrodes can be almost any conductor, however, it is good to 
have a curved and smooth surface which is capable of handling the arc 
current. They should also dissipate heat well. A common method is to use 
segments of copper pipe as the electrodes and to use a fan running over the 
electrodes while running the coil. This keeps the electrodes at a 
consistent temperature (as heat increases, the sparkgap will breakdown at 
lower and lower voltage potentials - the fan regulates this condition).

More Ascii art:

-------   -------   -------
|   e   | |   e   | |   e   |
|   l   | |   l   | |   l   |
|   e   | |   e   | |   e   |
|   c   | |   c   | |   c   |
|   t   | |   t   | |   t   |
|   r   | |   r   | |   r   |
|   o   | |   o   | |   o   |
|   d   | |   d   | |   d   |
|   e   | |   e   | |   e   |
*-------   -------   -------*
|        ^         ^        |
|        |         |        |
|       gap       gap      |
|                           |
|                           |
nst                        nst




Take care,
Bart

>Your help will be of great assistance for me.
>
>Best wishes and happy holidays.
>Nir (NOT NEAR) Weingarten
>Israel
>
>=====
>
>Best wishes
>
>                                               Nir(NOT NEAR) Weingarten
>
>Israel
>
>
>
>
>