RE: Tesla Coil Blunders

["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>


Bob -

Your discovery of the 10% reduction in calculated TC resonant frequency
agrees with the data I have collected over the years. Only a few coilers
test their coils for resonant frequency during actual TC operation using a
scope or frequency counter. The operating current in the secondary coil
definitely affects the coil inductance. I have not been able to find a
method to allow for this reduction at the design stage. As Terry says we
need new TC computer programs.

John Couture.

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

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, March 28, 2001 4:03 PM
To: tesla-at-pupman-dot-com
Subject: Re: Tesla Coil Blunders


Original poster: "bob golding by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<yubba-at-clara-dot-net>

Hi Gary,all,
    At the risk of sounding pedantic I don't think you can have "DC
inductance". I think
inductance is usually measured at something like one Khz. It is on my
bridge anyway. Please feel
free to flame away if I have got this wrong. I have found that the "fudge
factor" on  the tuning
of my big coil is about 10 per cent lower than the calculated figure, and
also from measuring it
using  Johns scope s.g and counter method.  It was a bit closer with the
spectrum analyser,but
still lower. When I get this 30" sphere  i should be able to run at full
power without any
breakout. I will check the res freq with the spectrum analyser and report
back.

cheers
bob golding