Frequency Splitting
Date: Mon, 13 Feb 2006 23:35:56 -0700
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Frequency Splitting (Was: Tc first start)
Original poster: "C. Sibley"
<a37chevy@yahoo.com>
Dr. Res,
What is frequency splitting as you mentioned below? New term to me...
Curt.
--- Tesla list <tesla@pupman.com> wrote:
> Original poster: "D.C. Cox" <resonance@jvlnet.com>
>
>
> Most coils only produce short sparks on
fire-up. Don't get
> discouraged! This is normal!!
>
> Using a small wire taped to your toroid you can
check the distance to
> a ground stand to see the max spark distance.
>
> Next, the tuning process begins. You should
always start with a
> "scrap wire" primary of 20-25 turns so you can
investigate a wide
> range of primary inductance to bring your system
into
> resonance. Start at 3 turns out and keep moving
the
> tap out as you check each turn for "best
resonance point".
>
> While doing tuning, keep your total sparkgap
tight,
> usually around 0.100 inches. This will prevent
high outputs which
> could damage your secondary coil if it's out of
resonance with the
> primary coil.
>
> Also, be sure to never exceed 30-35% on your
variac
> setting. Again, keep this low until you get
your primary in resonance with your
> secondary. The best resonance point at these
tight sparkgap and
> variac settings may only produce a spark 3-5
inches long. This is normal.
>
> After finding the proper primary number of turns
for resonance, now
> you can open up the sparkgap total setting to
0.180 or 0.200 inches
> max setting. Then you can run the variac up to a
higher level, ie, up
> to 100% and keep moving your groundstand back to
see the longest
> striking distance.
>
> After the above tuning procedures you will be
> hitting longer sparks,
> and at this point you can replace the scrap wire
> primary with a #6
> bare copper wire primary (like Home Depot #6 AWG
> ground wire) held in
> place with plastic holders.
>
> If your coil has a sec. coil of more than 4
inches
> dia. then a flat
> spiral primary is always the best setup. Using
> angle primaries can
> produce overcoupling and frequency splitting
which
> leads to serious
> problems causing sec coil damage.
>
> Set up your scrap wire primary and let us know
how
> it's
> working. also, specs on what you have would be
> helpful.
>
> Dr. Resonance
>
>
> ----- Original Message ----- From: "Tesla list"
> <tesla@pupman.com>
> To: <tesla@pupman.com>
> Sent: Monday, February 13, 2006 10:05 AM
> Subject: Tc first start
>
>
> >Original poster: "Adriano Mollica"
> <adriano.mollica@uniroma1.it>
> >
> >Hello to everyone,
> >
> >this week end i did the first start to the
tesla
> coil i built.
> >
> >Of course it doen't work...
> >
> >too b
msnip...
Date: Tue, 14 Feb 2006 11:36:52 -0700
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting (Was: Tc first start)
Original
poster: "D.C. Cox" <resonance@jvlnet.com>
After coeff. of coupling increases past it's "critical value" the
single resonant frequency of the secondary begins to split apart
into two separate frequencies. This means the HV is not achieved at
the very top of the coil but at some point lower in the sec windings
which causes flashovers and racing sparks. As an example, a typical
4 inch dia. sec coil should be elevated above the primary coil (flat
spiral) by 2 inches. Larger coils require even more elevation for
best performance. You can experiment by using small blocks of wood
to elevate your sec coil in 1/2 inch increments until best output
spark is achieved. Using Bob Svangren's (ref TCBA Newsletters)
segmented HV sparkgap provides excellent measurement of these small
increases that might not be noticeable to the human eye.
An excellent description of this is in the ARRL Radio Amateur's
Handbook available in any local library. Study this in detail.
Dr. Resonance
>Dr. Res,
>
>What is frequency splitting as you mentioned
below?
>Ne term to me...
>
>Curt.
>
>
>--- Tesla list <tesla@pupman.com> wrote:
>
> > Original poster: "D.C. Cox" <resonance@jvlnet.com>
> >
> >
> > Most coils only produce short sparks on
fire-up.
> > Don't get
> > discouraged! This is normal!!
> >
> > Using a small wire taped to your toroid you
can
> > check the distance to
> > a ground stand to see the max spark distance.
> >
> > Next, the tuning process begins. You should
always
> > start with a
> > "scrap wire" primary of 20-25 turns so you can
> > investigate a wide
> > range of primary inductance to bring your
system
> > into
> > resonance. Start at 3 turns out and keep
moving the
> > tap out as you
> > check each turn for "best resonance point".
> >
> > While doing tuning, keep your total sparkgap
tight,
> > usually around
> > 0.100 inches. This will prevent high outputs
which
> > could damage your
> > secondary coil if it's out of resonance with
the
> > primary coil.
> >
> > Also, be sure to never exceed 30-35% on your
variac
> > setting. Again,
> > keep this low until you get your primary in
> > resonance with your
> > secondary. The best resonance point at these
tight
> > sparkgap and
> > variac settings may only produce a spark 3-5
inches
> > long. This is normal.
> >
> > After finding the proper primary number of
turns for
> > resonance, now
> > you can open up the sparkgap total setting to
0.180
> > or 0.200 inches
> > max setting. Then you can run the variac up to
a
> > higher level, ie, up
> > to 100% and keep moving your groundstand back
to see
> > the longest
> > striking distance.
> >
> > After the above tuning procedures you will be
> > hitting longer sparks,
> > and at this point you can replace the scrap
wire
> > primary with a #6
> > bare copper wire primary (like Home Depot #6
AWG
> > ground wire) held in
> > place with plastic holders.
> >
> > If your coil has a sec. coil of more than 4
inches
> > dia. then a flat
> > spiral primary is always the best setup.
Using
> > angle primaries can
> > produce overcoupling and frequency splitting
which
> > leads to serious
> > problems causing sec coil damage.
> >
> > Set up your scrap wire primary and let us know
how
> > it's
> > working. also, specs on what you have would
be
> > helpful.
> >
> > Dr. Resonance
> >
> >
> > ----- Original Message ----- From: "Tesla
list"
> > <tesla@pupman.com>
> > To: <tesla@pupman.com>
> > Sent: Monday, February 13, 2006 10:05 AM
> > Subject: Tc first start
> >
> >
> > >Original poster: "Adriano Mollica"
> > <adriano.mollica@uniroma1.it>
> > >
> > >Hello to everyone,
> > >
> > >this week end i did the first start to the
tesla
> > coil i built.
> > >
> > >Of course it doen't work...
> > >
> > >too b
>msnip...
Date: Tue, 14 Feb 2006 16:10:02 -0700
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting (Was: Tc first start)
Original
poster: Timjroche@aol.com
Dr.,
"After coeff. of coupling increases past it's "critical value" the single
resonant frequency of the secondary begins to split apart into two separate
frequencies. "
Is this only when spark gap is conducting? Is it not true that when the gap is
quenched, the secondary will resonate at its natural frequency?
Tim
Date: Tue, 14 Feb 2006 17:45:02 -0700
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting (Was: Tc first start)
Original poster: "D.C. Cox"
<resonance@jvlnet.com>
Yes, but pri-sec reflections can produce bad effects during this period. This
can produce irregular resonant peak potential points up and down the sec coil
which can lead to damage.
The ARRL Radio Amateur's Handbook will detail these effects. See your local
library.
Dr. Resonance
Date: Sat, 18 Feb 2006 10:04:15 -0700
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting (Was: Tc first start)
Original poster: "Antonio Carlos
M. de Queiroz" <acmdq@uol.com.br>
Tesla list wrote:
>Original poster: "D.C. Cox" <resonance@jvlnet.com>
>
>After coeff. of coupling increases past it's
"critical value" the
>single resonant frequency of the secondary
begins to split apart
>into two separate frequencies. This means the HV
is not achieved at
>the very top of the coil but at some point lower
in the sec windings
>which causes flashovers and racing sparks. As an
example, a typical
>4 inch dia. sec coil should be elevated above the
primary coil (flat
>spiral) by 2 inches. Larger coils require even
more elevation for
>best performance.
>You can experiment by using small blocks of wood
to elevate your sec
>coil in 1/2 inch increments until best output
spark is
>achieved. Using Bob Svangren's (ref TCBA
Newsletters) segmented HV
>sparkgap provides excellent measurement of these
small increases
>that might not be noticeable to the human eye.
>An excellent description of this is in the ARRL
Radio Amateur's
>Handbook available in any local library. Study
this in detail.
I'm sorry, but this is incorrect. Any reasonable Tesla coil operates deep into
the region where two very distinct resonances can be observed. Actually, there
are always two different resonances when two resonant tanks are coupled in any
way. What happens is that if the losses are really big the two peaks merge in a
single peak, if you try to find them with a frequency sweep. The two resonances
are what causes the beats during the energy transfer. The splitting is due to
the presence of the two coupled systems, primary and secondary, and has no
relation with the other resonances of the secondary coil.
Antonio Carlos M. de Queiroz
Date: Sat, 25 Feb 2006 12:34:13 -0700
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting (Was: Tc first start)
Original poster: "Dmitry (father
dest)" <dest@himplast.ru>
Hallo Antonio,
Saturday, February 18, 2006, 11:04:15 PM, you wrote:
> Original poster: "Antonio Carlos M. de Queiroz"
<acmdq@uol.com.br>
> Tesla list wrote:
>>Original poster: "D.C. Cox" <resonance@jvlnet.com>
>>
>>After coeff. of coupling increases past it's
"critical value" the
>>single resonant frequency of the secondary
begins to split apart
>>into two separate frequencies. This means the
HV is not achieved at
>>the very top of the coil but at some point lower
in the sec windings
>>
> I'm sorry, but this is incorrect. Any reasonable
Tesla coil operates
> deep into the region where two very distinct
resonances can be observed.
can i save some of my time (for studying sync motors : D) and get the answer
from you, instead of finding it by myself? please : ) besides, i`m not only one
who read this list, sooo - : )
the question is - the primary circuit alters Fres of secondary while sg fires,
so secondary still resonates at it`s natural Fres (_other_ Fres)? then "This
means the HV is not achieved at the very top of the coil but at some point lower
in the sec windings" is incorrect too?
-----
Let the bass kick! =:-D
Date: Tue, 23 May 2006 15:09:08 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original poster: Jared E
Dwarshuis <jdwarshui@emich.edu>
I cringe when I see the words "frequency splitting", and I will tell
you why.
We could take two identical tank circuits and couple them. We will still get a
beat frequency.
Ah , but what about "frequency splitting?"
Be realistic, they are identical tank circuits. One tank could not possibly
operate at a different frequency then the other. There is no "splitting".
However both tank circuits will now operate at a frequency that is different
from the uncoupled state.
" There Is always a word or a phrase to be substituted for when meaning is
lacking" (Imanuel Kant, paraphrased, and translated)
Sincerely: Jared Dwarshuis
Date: Tue, 23 May 2006 18:29:07 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original
poster: Ed Phillips <evp@pacbell.net>
I cringe when I see the words "frequency splitting", and I will tell you why.
We could take two identical tank circuits and couple them. We will still get a
beat frequency.
Ah , but what about "frequency splitting?"
Be realistic, they are identical tank circuits. One tank could not possibly
operate at a different frequency then the other. There is no "splitting"."
With two identically-tuned circuits, before the spark gap quenches there will
certainly be two frequencies present, with separation determined by the degree
of coupling. Is that "frequency splitting"?
All a matter of definition I guess. Of course, when the gap opens the secondary
will ring with the fundamental resonant frequency.
Ed
Date: Tue, 23 May 2006 18:29:21 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original poster: FIFTYGUY@aol.com
In a message dated 5/23/06 5:13:15 PM Eastern Daylight Time,
tesla@pupman.com writes:
>We could take two identical tank circuits and
couple them. We will
>still get a beat frequency.
>
>Ah , but what about "frequency splitting?"
>
>Be realistic, they are identical tank circuits.
One tank could not
>possibly operate at a different frequency then
the other. There is
>no "splitting".
Doesn't a "beat frequency" result from two signals of different frequency? If
so, what is the source of the other frequency? If not, how else does a "beat"
result?
>However both tank circuits will now operate at a
frequency that is
>different from the uncoupled state.
Are you saying the above observed "beat frequency" is the difference between the
common "coupled frequency" and the common "uncoupled frequency"?
-Phil LaBudde
Date: Tue, 23 May 2006 19:20:01 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original poster: "Daniel
McCauley" <dhmccauley@easternvoltageresearch.com>
When two resonant circuits are coupled together, the frequency
response contains two distinct peaks at two different
frequencies. This is a result of
each circuit seeing "more" of the capacitance of the other's circuit
when they are coupled together. So, the fres of one goes up, and the
fres of one goes down, and
this is what you see when you perform an AC response of the coupled
resonant circuits.
The beat frequency is the upper pole - the lower pole. The beat
frequency is also the frequency at which primary notching
occurs. Richie Burnett has some good
theory on this subject on his website.
Dan
> >We could take two identical tank circuits and
couple them. We will
> >still get a beat frequency.
> >
> >Ah , but what about "frequency splitting?"
> >
> >Be realistic, they are identical tank circuits.
One tank could not
> >possibly operate at a different frequency then
the other. There is
> >no "splitting".
> Doesn't a "beat frequency" result from two
signals of different
> frequency? If so, what is the source of the
other frequency? If
> not, how else does a "beat" result?
>
> >However both tank circuits will now operate at
a frequency that is
> >different from the uncoupled state.
>
> Are you saying the above observed "beat
frequency" is the
> difference between the common "coupled
frequency" and the common
> "uncoupled frequency"?
>
>-Phil LaBudde
Date: Tue, 23 May 2006 19:20:16 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original poster: <a1accounting@bellsouth.net>
Hi Ed,
>
>>
>
> I cringe when I see the words "frequency
splitting", and I will tell you why.
>
> We could take two identical tank circuits and
couple them. We will
> still get a beat frequency.
>
> Ah , but what about "frequency splitting?"
>
> Be realistic, they are identical tank circuits.
One tank could not
> possibly operate at a different frequency then
the other. There is no "splitting"."
If the identical tank circuits are coupled, you are correct one tank does not
operate at a different frequency (single). What happens is the original
resonance in both tanks are replaced by two new resonances at either side of the
original frequency ie the original frequency is split in to two frequencies.
Both the secondary and
primary have these two new resonances.
>
> With two identically-tuned circuits, before
the spark gap
> quenches there will certainly be two frequencies
present, with
> separation determined by the degree of coupling.
Is that "frequency splitting"?
> All a matter of definition I guess. Of course,
when the gap opens
> the secondary will ring with the fundamental
resonant frequency.
>
> Ed
Date: Tue, 23 May 2006 19:20:28 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original poster: Ed Phillips <evp@pacbell.net>
>However both tank circuits will now operate at a
frequency that is
>different from the uncoupled state.
Are you saying the above observed "beat frequency" is the difference between the
common "coupled frequency" and the common "uncoupled frequency"?
-Phil LaBudde "
No - the "beat frequency" is the sum of the two COUPLED MODE frequencies, which
shows maxima and minima a a rate corresponding to the difference between the two
frequencies. Reall two different sine waves added together which appear to
beat..
Ed
Date: Tue, 23 May 2006 19:20:40 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original poster: "Daniel
McCauley" <dhmccauley@easternvoltageresearch.com>
Sorry Jared, that is incorrect on both accounts.
If you had two identical tank circuits and coupled them together,
there would be no beat frequency. Of course in the real
world with tolerances on components, you would get a very small one,
but in the ideal case, there would not be a beat frequency
or frequency splitting as the amount of C each side sees would be identical.
Also, even with frequency splitting, the tank circuit doesn't operate
a one single frequency. It operates with components of both
major splitting frequencies (lack of a better word to call them) as
well as additional harmonics which are very small compared to these
two major frequency modes.
Dan
Date: Tue, 23 May 2006 20:25:16 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original poster: "Dr. Resonance"
<resonance@jvlnet.com>
The resonance points occur at two different frequencies each
equidistant from the resonant peak. Maybe frequency splitting isn't
the best term but two separate resonant freqs occur with overcoupling
which produces two separate points along the coil when potential
peaks occur. Then, these two pure freqs start "beating" against each
other and standing waves occur.
Dr. Resonance
----- Original Message ----- From: "Tesla list" <tesla@pupman.com>
To: <tesla@pupman.com>
Sent: Tuesday, May 23, 2006 7:20 PM
Subject: Re: Re: Frequency Splitting
>Original poster: <a1accounting@bellsouth.net>
>
>Hi Ed,
> >
> >>
> >
> > I cringe when I see the words "frequency
splitting", and I will tell
> > you why.
> >
> > We could take two identical tank circuits and
couple them. We will
> > still get a beat frequency.
> >
> > Ah , but what about "frequency splitting?"
> >
> > Be realistic, they are identical tank
circuits. One tank could not
> > possibly operate at a different frequency then
the other. There is
> > no "splitting"."
>
>If the identical tank circuits are coupled, you
are correct one tank
>does not operate at a different frequency
(single). What happens is
>the original resonance in both tanks are replaced
by two new
>resonances at either side of the original
frequency ie the original
>frequency is split in to two frequencies. Both
the secondary and
>primary have these two new resonances.
>
> >
> > With two identically-tuned circuits,
before the spark gap
> > quenches there will certainly be two
frequencies present, with
> > separation determined by the degree of
coupling. Is that "frequency
> > splitting"?
> > All a matter of definition I guess. Of
course, when the gap opens
> > the secondary will ring with the fundamental
resonant frequency.
> >
> > Ed
Date: Tue, 23 May 2006 21:41:25 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original
poster: "Daniel McCauley" <dhmccauley@easternvoltageresearch.com>
The resonant points, as you state, are not equidistance from the
resonant peak. Each one is different, and can be defined by
the following equations:
Fupper = Funcoupled / sqrt (1-k)
Flower = Funcoupled / sqrt (1+k)
where k = coupling between the two resonant circuits
Dan
>The resonance points occur at two different
frequencies each
>equidistant from the resonant peak. Maybe
frequency splitting isn't
>the best term but two separate resonant freqs
occur with
>overcoupling which produces two separate points
along the coil when
>potential peaks occur. Then, these two pure
freqs start "beating"
>against each other and standing waves occur.
>
>Dr. Resonance
Date: Wed, 24 May 2006 10:27:11 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original poster: "Dr. Resonance"
<resonance@jvlnet.com>
When we scope our coils and set the coeff of coupling the freqs move
off of center evenly in both directions. I suppose it is possible to
get one different from the other but in all cases I have seen
involving TC tuning they always move to both left and right an even
amount of space on the scope indicating equal off freq from center
freq resonance points. When we adjust coeff of coupling with our
drive motor I have never seen one point move more than the opposite
freq point. This is, of course, without HVpower using only a sig gen
as driving source.
Dr. Resonance
>Original poster: "Daniel McCauley" <dhmccauley@easternvoltageresearch.com>
>
>The resonant points, as you state, are not
equidistance from the
>resonant peak. Each one is different, and can be
defined by
>the following equations:
>
>Fupper = Funcoupled / sqrt (1-k)
>
>Flower = Funcoupled / sqrt (1+k)
>
>where k = coupling between the two resonant
circuits
>
>Dan
>
>
>>The resonance points occur at two different
frequencies each
>>equidistant from the resonant peak. Maybe
frequency splitting
>>isn't the best term but two separate resonant
freqs occur with
>>overcoupling which produces two separate points
along the coil when
>>potential peaks occur. Then, these two pure
freqs start "beating"
>>against each other and standing waves occur.
>>
>>Dr. Resonance
Date: Wed, 24 May 2006 10:27:46 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency Splitting
Original poster: Paul Nicholson <paul@abelian.demon.co.uk>
Hi All,
Many varied interpretations being presented here...
Dan wrote:
> If you had two identical tank circuits and
coupled them
> together, there would be no beat frequency.
That bit's wrong. Perfect symmetry is no problem: the dual
resonance behaviour is just fine when both LC units are identical.
This is a common misunderstanding,
> the fres of one goes up, and the fres of one
goes down,
That's the source of the error. It's incorrect to assign one
frequency to one coil and the other frequency to the other coil.
The important thing is that both of these modes involve a joint
resonance of both coils. Hence there's no need for the symmetry
breaking requirement which Dan suggested above.
Having said that, if one coil has its uncoupled Fres different
to the other, there will be a difference in amplitudes of the
two modes in each coil. The low frequency coil will have a
higher proportion of V,I in the lower mode, and vice versa.
The result under these conditions is incomplete instantaneous
amplitude cancellation at the notches, resulting in incomplete
energy transfer and difficult or impossible quenching - the
system is 'out of tune'.
> When two resonant circuits are coupled together,
the frequency
> response contains two distinct peaks at two
different
> frequencies.
Two different frequencies, yes, but only distinct on a 'sweep' if
k is greater than about 1/Q.
D.C. wrote:
> Maybe frequency splitting isn't the best term
There are some grounds for arguing that. In bringing up another
resonator to the first, a second 'degree of freedom' is being
introduced. It only appears as a 'splitting' of the previous
single mode when the new resonator has its uncoupled Fres close
to that of the first. It sure looks like a splitting when
you watch the sweep as the coupling is increased, but it doesn't
look at all like a splitting if you start with overcoupled k
but with one coil tuned to a very low Fres. As you raise the
Fres of that coil towards the other, the sweep will show the
lower resonance peak appearing to 'push' the other resonance
away.
> two separate resonant freqs occur with
overcoupling which
> produces two separate points along the coil when
potential
> peaks occur.
That's not quite right. For both modes, the potential peaks
are at the secondary top.
> these two pure freqs start "beating" against
each other and
> standing waves occur.
Seen in the time domain, they beat together to produce the
desired beat envelope and notches.
But...standing waves always occur, regardless of k, so long as
Q is greater than about 6. We *want* the standing waves - they
are just another name for a resonance or 'mode'. It's incorrect
to suggest that standing waves only occur during overcoupling
and are undesirable.
(Of course, standing waves - resonances - higher than the two
which make up the beat *are* likely to be undesirable because
they do create additional voltage maxima within the secondary.)
Paul Nicholson
Manchester, UK.
--
Date: Wed, 24 May 2006 10:30:32 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original poster: <a1accounting@bellsouth.net>
Hi,
> Original poster: "Daniel McCauley" <dhmccauley@easternvoltageresearch.com>
>
> The resonant points, as you state, are not
equidistance from the
> resonant peak. Each one is different, and can
be defined by
> the following equations:
>
> Fupper = Funcoupled / sqrt (1-k)
>
> Flower = Funcoupled / sqrt (1+k)
>
> where k = coupling between the two resonant
circuits
>
Actualy only true for simple (lumped) resonators. A more accurate version for
our case would be
Fupper = Funcoupled / sqrt (1-k -(k^3)/6..)
Flower = Funcoupled / sqrt (1+k+(k^3)/6..)
which is an educated guess just to be provocative
snip
Date: Wed, 24 May 2006 10:32:44 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original poster: <a1accounting@bellsouth.net>
Hi,
>
>
> Original poster: "Dr. Resonance" <resonance@jvlnet.com>
>
>
> The resonance points occur at two different
frequencies each
> equidistant from the resonant peak. Maybe
frequency splitting isn't
> the best term but two separate resonant freqs
occur with overcoupling
> which produces two separate points along the
coil when potential
> peaks occur. Then, these two pure freqs start
"beating" against each
> other and standing waves occur.
>
The each of the two resonances frequencies in the secondary are
caused by the standing waves. You could call them standing wave
resonances or wave resonances.
The wave is reflected at the top end and reflected at the bottom
end. At the bottom end the reflected impedance of the primary allows
two possible resonances.
One way to look at the wave resonance is to say that the reflected
waves from both the top and bottom are such that they beat and
reinforce each other.
>From the perspective of the primary the two
resonances (lumped) are
caused by the refered impedance of the secondary which is, due to the
wave resonance, can be L or C either side of its normal wave resonance.
Date: Wed, 24 May 2006 12:07:52 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Re: Frequency Splitting
Original poster: <a1accounting@bellsouth.net>
Hi Dr,
>
> Original poster: "Dr. Resonance" <resonance@jvlnet.com>
>
> When we scope our coils and set the coeff of
coupling the freqs move
> off of center evenly in both directions. I
suppose it is possible to
> get one different from the other but in all
cases I have seen
> involving TC tuning they always move to both
left and right an even
> amount of space on the scope indicating equal
off freq from center
> freq resonance points.
Yes your correct. For K up to about 0.2 thats what you would see given by the
following aproximation
Fupper = Funcoupled / (1-k/2)
Flower = Funcoupled / (1+k/2)
>When we adjust coeff of coupling with our
> drive motor I have never seen one point move
more than the opposite
> freq point. This is, of course, without HVpower
using only a sig gen
> as driving source.
>
> Dr. Resonance
Date: Wed, 24 May 2006 22:37:32 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Frequency splitting...... Food For Thought
Original poster: Jared E
Dwarshuis <jdwarshui@emich.edu>
We can actually use a mechanical model of a tuned coupled oscillator to gain
insight into the nature of the phenomena of "Frequency Splitting"
We can have a spring stuck to a wall with a spring constant k and a mass m .
Then we add a coupling spring (k prime) then an identical mass followed by
another duplicate spring k (which we attach to the adjacent wall).
Now we need a relevant starting point. Let us hold the left mass stationary at
its natural resting point where displacement equals zero.
Let us now displace the right mass an arbitrary unit of 1 to the right of its
natural resting point.
Now let us examine the predicted frequency of the left mass at the instant where
time equals zero. It is simply: w = sqrt (k/m). But what is the instantaneous
frequency at time equals zero of the right side's mass that is displaced one
unit. It is: w = sqrt(( k plus Kprime)/m)
Now the interesting part, is that given a duration of time we will find that
the mass on the left has been displaced by -1 unit, and the mass on the right
will have zero displacement. Thus at this instant in time, they have switched
frequencies, where the right side now has the left sides old frequency, and the
left side now has the right sides old frequency.
Implication: The frequency for a given side is constantly changing between sqrt
(k/m) and the sqrt of ( k plus k prime)/ m.
Sincerely: Jared Dwarshuis