RE: Resonance - what is it? and OLTC stuff

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

Original poster: "harvey norris by way of Terry Fritz <twftesla-at-qwest-dot-net>" <harvich-at-yahoo-dot-com>


--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "John H. Couture by way of Terry
> Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> 
> 
> Jonathon -
> 
> I reread my post below and realized that the barn
> door cap is a neat
> demostration of voltage rise but it is not a
> demonstration for resonance.
> Resonance has to do with RCL circuits and
> frequencies and a different
> equation. The equation is
>         Fr = 1/(2pi sqrt(LC))
> With a series circuit and at resonance the current
> is maximum and the rise
> in voltage occurs across the C or L.
The basic laws of source frequency resonance sometimes
get confused when applied with tesla coils having an
arc gap throwing the system into high frequency.
Notable in this confusion is the equating of a tank
circuit with voltage rise. A "source frequency"
resonant tank circuit, or parallel resonance, has no
voltage rise, instead it has a "resonant rise of
amperage" with respect to the amperage inputed into
the loop. A series resonance does have a voltage rise
with respect to the voltage inputed, but this voltage
rise,(predicted by X(L)/R) is internal to the circuit,
present at the midpoint between the L and C quantities
in series. This voltage rise is a voltage against
itself internally in the series resonance, meaning the
voltage rise is present in both the L and C
quantities, but is in opposite directions or ~180 out
of phase with each other. 
http://groups.yahoo-dot-com/group/teslafy/files/Neon%20Schematic.gif
shows a alternator 3 phase voltage rise circuit in 3
stages with neons as the last stage. The L and C
quantities could be configured for any frequency by
the Thompsons resonance formula you have mentioned.
The quantities in that schematic were configured for a
188 hz resonance, which had difficulty in
simultaneously lighting 3 neons in delta. At 480 hz
using newly configured L and C quantites for the
schematic this difficulty was easily overcome and the
neons could be configured in either delta as shown, or
in wye. The inner blue Delta Series Resonances,(DSR)
provide for an additional voltage rise beyond what the
outer DSR (green) supplies to it from its voltage rise
beyond  that what the alternator supplies as the
source voltage. Thus in that schematic TWO voltage
rises become necessary to approach the voltage
necessary to light the neons, and the end voltage in
the last delta neon triangle is actually 1.7 times
that found in the second voltage rise.(If open circuit
voltages were to be measured)

Now imagine that the schematic instead had no
additional inner components, but instead had a WYE
short across those outer midpoints. If we then looked
at the schematic in a different way we would see that
this was also a 3 phase tank circuit, but now the C
value to be used for its resonance comes from the
adjacent phase, and also that each tank circuit has a
shared line with the adjacent tank circuit on each
side.( this is the line connections of the inner WYE
short of the former series resonances) Since the C
value has been changed to use the one on the phase
adjacent to the series resonant one, all three tanks
must be identical for the situation to apply. In that
situation there is instead a resonant rise of amperage
beyond that inputed by the source, and we should
expect another rise of amperage on the shared lines of
the WYE, this being 1.7 of that found on the outside
of the triangle.
WYE Short on DSR 
Here a 20.16 volt stator only inputs ~ 2 ma to the
three phase tanks,( measured from the  2 of the 3
stator lines themselves) and as noted the impedance of
a tank circuit is Q times higher that the reactance of
the coil system itself. It is Q squared higher than
the conditions for a series resonance, where the
resistance of each coil system of ten 14 gauge wire
spools in series is ~ 12.5 ohms. The resonant rise of
amperage is 30.7 ma made from that 2 ma input, for an
acting tank Q of 30.7/2= ~ 15.3  We should then expect
1.7 times that value or 52.2 ma on the shared lines of
the  tanks in WYE, but here perhaps because of
inbalances on the  3 identical tank requirements, the
meter reads 44.4 ma on the shared lines.


 With a parallel
> circuit and at
> resonance the impedance is a maximum and the voltage
> rise occurs across the
> C and L.
Again here I have tried to show that no voltage rise
occurs in a tank circuit, instead an amperage rise
occurs as a consequence of the increased impedance. 
> The Q factor of the coil is a ratio of  2piFr/R  and
> is an indicator of how
> high the voltage may rise. The voltage will be
> higher if the coil inductance
> is higher or the resistance is lower.
> 
> John Couture
I am not familiar with that method of calculating a Q
factor. I always simply use [(ACTING)X(L)]/R for
series resonance, and Amps(int)/Amps (inputed)) for a
parallel resonance. I also find that q factors and in
some cases even reactance itself predicted by equation
dont always match that found by actual measurements,
which is why I use the term "acting Q", In fact in
these alternator studies of source frequency resonance
for a certain Q factor found at series resonance, the
same capacity may give a different Q factor for
parallel resonance. See Differing Q factors for series
and parallel resonance;
http://groups.yahoo-dot-com/group/teslafy/message/435

Sincerely HDN