Re: tesla coil

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi,

At 07:46 PM 1/2/2001 -0500, you wrote: 
>
> How do you tap a primary?  Is that refering to moving the connecting wire a 
> little farther down the coil?  What's the point of that? Doesn't that make 
> all the coil above that connection rather useless?


As you change the tap point, the inductance of the primary changes and thus the
tuning.  If you tap less turns, the primary frequency goes up.  If you tap more
turns, the frequency goes down.  Thus, you can adjust the primary frequency to
math the secondary's frequency.

>
> What would happen if you were to add a secondary?  That is, wrap another 
> tight coil around the primary with the same number of loops as the inner 
> secondary. Then, attach the two together?  Would that magnify it?  Or would 
> the induction cancel itself out, causing a loss of output?


The two coils would need to have the same inductance and all.  This would drop
the secondary frequency in half.  I can think of no advantage and arcing
between the coils would probably be a giant problem.  I do not know of this
ever being done.

>
> Will 20 gauge bell wire work, or must it be magnet wire?


As long as you can still get the needed number of turns so it all tunes, it
will work fine.  Magnet wire will give you many more turns which is generally
believed to help arc length.

>
> I'm having a bit of a problem.  When winding the secondary, how do I keep the
>
> coil from kinking? Or from accidently overlapping itself. it's not much of a 
> technical question, but I know it will affect my coil's output.  How do I 
> keep the loops from sliding over themselves, and how to I keep the secondary 
> taut when I'm not holding it?


You just have to keep the wire tight and have many strips of masking tap ready
to stick down the windings.  I tape the windings as I go so if the wire get
loose only a small section needs to be messed with.  Others will have more tips
on this one...

Cheers,

        Terry