[NewCandle] Resonance and Circulation: an introduction

[Keith Nagel]

Hi Nick,

Nonlinear elements like diodes are good for another purpose;
with them you can build circuits that defeat the limitation
in voltage/current rise that I briefly described in linear
circuits. I have build resonators where the injected frequency
is half the resonant frequency, the diode's job is to convert
from the low frequency to the resonant frequency. If the
cavity is a tranmission line, you can inject the low frequency
component at a node of the high frequency component, and
not have the usual feedback that accompanies a single frequency
resonance. But that's the topic of another stemwinder (grin).

It's been a while since I messed with piezo's, but if I remember
correctly at resonance the piezo looks like a parallel resonant
circuit, and at antiresonance the pieze looks like a series resonant
circuit. Hence your obs. that the impedance is very high for
the first and very low for the second. The obs. of a low frequency
sound in the head is quite interesting. Not sure what to make
of it, but I _must_ ask if you were able to achieve the effect
at any distance. I could think of some killer uses for the
effect if you could do it within a range of say 10-20 feet.

K.

-----Original Message-----
From: newcandle-bounces at ipdiscover.com
[mailto:newcandle-bounces at ipdiscover.com]On Behalf Of Nick Reiter
Sent: Saturday, September 01, 2007 8:41 AM
To: New energy for the new world.
Subject: Re: [NewCandle] Resonance and Circulation: an introduction


Good morning Keith,

Would another method of producing - injecting - a
travelling wave into a closed loop so that it forms in
phase resonance be the use of active electronic
materials.... in other words, insert in series with
your center ring conductor a set of diodes, all
oriented the same way.

What does the world of mechanical resonance have to
offer as analogue?  Can we learn lessons from that?

A number of years back, a peculiar effect I was shown
prompted me to spend some time trying to understand
piezoelectric transducers.  The said effect is one
that I don't have an explanation for to this day,
though obviously one exists.  And it may not really be
all that germane to this discussion, other than to
point out that there may be modes of resonance
mechanically or electro-mechanically that could offer
insight into your ring problem.

Back in the early 90s, a friend of mine from Cleveland
picked up some early PZT discs - lead zirconate
titanate.  These were about 2.5 inch diameter by maybe
.125 thick, silvered on either side with a polarity
marker.  Alan had apparently been playing around with
trying to use these to induce high frequency sound
into the human body, ala neurophone or whatever.  He
was using about a 10W signal generator to pump the
disc in use.  Anyway, he found that at a particular
high frequency - around 45KHz, when the transducer
face would be held against the skin most anywhere on
the body, a high pitched but audio tone would be heard
within the head.  the apparent frequency of the tone
(to me at least) was about 2 or 3 kHz.

I played with it myself for several months, and was
able to obtain a spec sheet for the PZT discs.  Thats
where resonance comes in and things got puzzling.  It
turned out that the PZT discs had both a resonant
frequency (which I think was like maybe 18 or 19 kHz)
and an "anti-resonant" frequency... which turned out
to be the ~45kHz frequency that would produce the odd
physiological / auditory effect!

Scoping things out, it simply did look like an inverse
resonance.  At resonance, the PZT disc experienced max
V, min I, and max mechanical deformation of the
lattice due to the potential.  At anti-resonance, the
disc became like a current sink essentially.  Of
course, what the audio thing was, I have no notion. 
It sits in my gallery of things that continue to make
me go "mhuhh?!"

I remember looking up info on anti-resonance, and also
recall just sort of getting lost at the time, and not
quite grasping it.  It seemed to be idiosyncratic to
piezoelectric crystals or lattices, but maybe there is
an analogue electronically.  And maybe something there
fits into your ideas, Keith.


Best,

N


> Hi All,
> 
> The understanding of the concept of resonance is
> fundamental to understanding
> the underpinnings of the physical world. Yet the
> phenomena itself is often
> shrouded in a mystery of mathematical
> approximations, sufficient to obtain
> a result yet providing little insight into true
> nature of the subject. Because those
> approximations are so simple they are often taught
> first to the student,
> who is left with a rather poor and confused
> understanding.
> The situation is analogous to the teaching of the
> Bohr model of the atom. The
> model works, but it takes years of additional
> teaching to undo the 
> inevitable conceptual misunderstandings that arise
> as a result... 
> 



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