# Re: Now, How does a coil really work??

```"If resonant rise does occur, why doesn´t the output (spark length) of
an
unloaded (!!) coil continue to grow the longer the coil operates? Of
course
there would be a limit to this, but any (unloaded) coil should
experience very
short streamers that will (have to) grow in length the longer the coil
runs. I
have never seen this happen.

The "resonant rise" is very real and occurs during the time before the
spark gap opens, isolating the primary circuit.  If circuit losses are
reasonably low and the correct coupling coefficient and gap "break time"
are achieved ALL of the energy which was originally stored in the
primary capacitor will have been transferred to the secondary.  With
high coupling coefficients this can happen in just a a cycle or so of
the resonant frequency.  With smaller coupling coefficients the energy
transfer may take place over a number of cycles. All of this probably
happens before ANY streamers form, and is repeated with each spark.
Someone recently posted measured waveforms illustrating all of this;
they agreed almost perfectly with simple theory.

"I do not mean that some arcs or streamers are longer than others.
Resonance
rise would force MOST streamers to continue to grow in length. Esp.
since the
energy needed to keep a streamer alive is less than is needed to let a
new
streamer form. In other words: when you plug in your coil you start out
with a
streamer of say 10". After a minute of running, this streamer would be
(e.g.)
20" long, etc. Plus a coil experiencing resonant rise shouldn´t
experience the

The experience with my (unloaded) coil has been that I get a (or
multiple)
streamer(s) of 20" and this length does NOT vary all too great. The
streamer
will connect to a grounded rod now and then (which is a little further
away
~2"), but if I place the grounded rod say an additional 2-4" away, the
streamer will never (!!) connect to it. If resonance rise DOES occur, it
should do this after a while, but it doesn´t.

A loaded coil will do this (growing arc or streamer length) to some
extend,
but I believe this is due to the fact that voltage is being stored on
the
toroid (!) and
slowly building up, before finally discharging.

What am I missing I.e. why do some guys (even experienced coilers) say a
TC
encounters resonant rise?

More confused than ever before,
Coiler greets from germany,
Reinhard"

Ed

```