Re: DC/AC sparks (Stop the nonsense)

["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: "rheidlebaugh by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>
> 
> A tesla coil is not a simple oscilator with contiouous AC power. 

A continuous-wave coil is.

> It is a
> pulse fed circuit. That is why a charge builds up on the toroid. If the
> drive was pure AC of a balanced sign wave the use of a toroid would be a
> waste of time.If you have an unbalanced + pulse a charge will build up on a
> "ststic" charged surface and will grow with each pulse, just like a
> VANDEGRAPH charging a sphere.

"Van de Graaff". A capacitor-discharge Tesla coil does -not- accumulate
and "DC" charge at the terminal. During the energy transfer process, 
the charge there swings a few times between positive and negative
values,
until the electric field around the terminal is high enough to cause
breakdown and start a spark. The spark is then fed by the charge
at the terminal at this instant, and if it connects to a grounded
object, it discharges the terminal with a spark very similar to the
spark of a VDG. There are differences, however. If there is still
energy in the magnetic field of the secondary coil, a continuous
current will keep the spark active for some time, until most of
the energy in the system is drained.  

> an antenna sencing the wave shape using a scope
> dosent see the DC part of the build up. You must use a space charge mesuring
> detector to read the total charge.

True, but there is no DC buildup. Even if there were, the charging is
fast enough for an oscilloscope to see everything correctly.

> I don't hear anyone trying to measure
> this level. Time after time I see postings of streamer size, but no one
> measures the voltage of the static charge required to make that streamer. I
> only see "OH goody Oh goody I got a big streamer".

It's quite difficult to make these measurements, but Terry, for example,
has voltage measurements in his web site.

> You get a sreamer when the
> AC builds up a DC component to a point that the air breakes down and the
> total AC & DC fires through the space of your play area.That is why most
> TUBE tc are less impressive.Yes total power is less, But pure AC dose not
> build up a charge.There must be a DC component to build a charge.BOTH !!!

AC is just a DC that varies, alternating polarity periodically. For the
time necessary to the formation of a spark. The frequencies involved in
the operation of a regular Tesla coil are almost DC...

Antonio Carlos M. de Queiroz