# [TCML] Is this right?

Bert Hickman bert.hickman at aquila.net
Sat Jan 12 07:29:59 MST 2008

```Hi Ben,

I really don't understand how Brooke Clark could have ever come to the
conclusion that a self-resonant coil has a Q of 1. This is easily
refuted by a few simple measurements, and most well constructed Tesla
Coil resonators easily achieve Q's in the range of 200 - 300. It sounds
like Mr. Clark is simply a bit confused about Tesla Coil operation and
Q is a measure of the energy stored in the inductor divided by the
energy lost PER CYCLE. One form of Q can be written as:

Q = 2*pi*Fr*L/Rac

where
Fr = resonant frequency
L = Inductance
Rac = equivalent resistance of inductor at Fr

It can easily be seen from the above equation (and easily experimentally
confirmed) that Q actually \$decreases when external capacitance is
added, since this lowers the resonant frequency of the circuit. There
are a significant number of other inaccuracies on Mr. Clark's site as
well...

The TCML used to modify all URL's and email addresses by substituting a
"dot" for a "." in an attempt to thwart 'bots from harvesting addresses
for spammers. Don't know how well this worked though.

Bert

Ben Sneath wrote:
> hello all,
> i found the on the website:  www.prc68.com/I/electron.shtml
> (if the link shows up)
>
> ...All of the above is very important since a coil operating
> at it's self resonant frequency has a Q of 1, no matter how
> it was made.  (This is something that 99.99% of the Tesla
> coil builders don't get.)  So in order to get high Q you
> need to load the coil with a capacitance that's
> substantially larger than the self capacitance.   You can
> see the it's very important to not only wind the coil in
> such a way that the HF resistance is minimized but also in
> such a way that the self resonant frequency is as high as
> possible...
>
>
> is this true? secondry with a Q of 1 no matter what when @
> its res. frequency?????
> if it is right then how does that happen??
>
> BTW...why in older posts was the "." replaced with the word