Re: New Transformerless Tesla Coil

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
> 
> Original poster: "Jolyon Vater Cox by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

> I see now...the Medhurst capacitance is 2.014715443 pF which leaves only
> 0.79518047pF for the topload -that is small!
> That would indicate a smaller diameter -a wooden curtain ring covered with
> foil perhaps?

Maybe you don't need a ring at all at this low power. Some extra primary
capacitance would allow for a larger terminal capacitance. A telescopic
antenna as the terminal works very well.

> A thumbtack balanced on the edge to be precise -got small blue streamer from
> the point ,not much more -also got smaller streamers/ corona from the sharp
> edges of the foil covering at the edges of the disc.

This indicates that the coil can't be too far from correct tuning.

If you have an oscilloscope around, make a 555 oscillator, oscillating
at a frequency ~100 times smaller than the operating frequency of the
coil, and connect its output to the gap (When the output goes down
the output impedance of the 555 is low enough for the test).  Look at 
the voltage over L1 or C1 at the oscilloscope and tune the system so 
a notch appears after ~5 cycles.

> SWG 24 is 0.022" which in metric is 0.5588mm
> a bit small perhaps?

It's a small coil. Looks good enough.

> How about using an ignition coil next?

More power. If you can obtain a high break rate, the output will
be more impressive. Try to improve the spark gap too. I can't obtain
much from my system with a single gap. A multiple gap is certainly 
better.

Antonio Carlos M. de Queiroz