Re: secondary question

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

Original poster: "Michael Rhodes by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rhodes-at-fnrf.science.cmu.ac.th>

Since the TC secondary looks and behaves like a distributed
capacitor, each pair of adjacent wires is a mini cap and the
charging and storage of the charge of these mini caps depend
on the dielectric constant (this would be the wire insulation
and air gap between the wires and also dependent upon the
resistivity of the coil form), you would have a gradient charge
on the coil.  The higher the resistivity of the coil form the
less drainage of the capacitance and thus the longer it will
maintain a charge. This would explain why the higher up
you go the more intense the shock and why some coil forms
are less susceptible to the effect. Looks something like this:

GND-----|-----|(------|-----|(-------|----|(------|--0
                |----res-----|----res------|----res----|

where 'res' is the coil form resistance/interwinding leakage
and --|(-- capacitance of each winding pair and '0' is the top
load.  So, if you have a 1000 turn secondary you would
have 500 mini capacitors in series.
		
When you turn off the power at a position where the top load
has not discharged, some energy has to be still stored in the coil.
One way of verifying this is to use a grounding rod (just a plastic
rod with a ground wire on the end) and short the top load to this
ground.  We use these on all our high voltage top terminals
and toroids and leave it connected as long as we are working
on the systems.  To preclude that it is not a static charge built
up in your body, ground yourself first to the rod to discharge
the static.

Just my theory on this phenomena, mileage may vary:-)

--Michael

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, July 12, 2001 9:39 PM
Subject: Re: secondary question



 > << Hi Everyone,
 >
 >       This weekend I just finished my first coil (6") and got results of 12"
 >  which was about what I expected due to no tuning, it's incomplete power
 >  supply and bad topload.  Well anyways I was running it at 30 second
 >  intervals making changes each time and after the 3rd run I noticed the
 >  secondary was a bit crooked.  So I discharged the caps and reached out and
 >  put my hands on the seconday to lift it to look at it and I got a
 >  surprizing shock.  I touched it a few more times and got a few more jolts
 >  and found the higher up I got the more powerful they were.  After about
 >  five jolts they died but after I powered the coil they came back.  I had
 >  never heard of this on any pages before (although I may be wrong) so I was
 >  surprized.  They weren't terribly powerful but they did fell a lot like
 >  static shocks from a Van De Graff generator, but I'm not sure how my coil
 >  could produce much static.  The only other guess I can make is that since
 >  the secondary exhibits isotropic (self) capacit!
 >  an!
 >  ce to the ground, it could retain a charge after the power is turned off.
 >  Has anyone else encountered this?  Does anyone know if these shocks are
 >  safe, because after writing this I feel like shocking myself maybe wasn't
 >  the smartest thing I could of done.
 >
 >        An admirer of coilers everywhere,
 >       -Will Daniels      >>
 >
 >
 >