A Pure Scientific Site

[Pieter]

Yes, that would be interesting since I use to be a consulting EE for an
old time capacitor company which recently closed down due to foreign
competition and lack of military orders.

http://webpages.charter.net/jamie_5"

Yes, everybody wants the cheap chinese crap nowadays. Lifetime of 1000
hours or less.

P.

 

[Pieter]

If you put wheels on a sled you have a wagon.

And if you remove the wheels of a car, you do not have a sled.

Nearly any sort of capacitor that can be used at high voltage should
be stored with its legs shorted. The plastic ones rated for 100V can
give you a nasty zap.

Pieter

 

[Mark Thorson]

And if you remove the wheels of a car, you do not have a sled.

But if you put skis on the wheel-less car,
you do have a sled.

 

[[email protected]]

Uhmm... By my own point of view, there is a big difference attributing
the electric charge increase (if any, as I already said, I never
investigated about) to the movement or to the dielectric itself.
It's like to say that the dynamo produces energy because of its coil
not because of it rotates by an external mechanical energy. _It's the
external energy incoming into the dynamo system which is converted to
electric energy_. The first hypothesis (where the motion is the cause
of the possible energy conversion) respects the law of conservation of
energy, while the second doesn't.

Massimo

You are quite right. But anyway you know that traditionally we name
a dynamo in a circuit as a source of potential, ie although a dynamo
is itself an object not energy, we have in mind its energy although
not explicitly stated.

 

[[email protected]]

This is his report which I have inserted in my paper:
| Oh, yes, indeed the resonant frequencies do change as
| drastically as you suggest if you put a dielectric with high
| dielectric constant between the parallel plates of a capacitor.
| I've put an example at the end of this posting.
|
| Example of capacitor with high-K dielectric...
| You can buy "disc ceramic" capacitors with about 1.0nF capacitance.
| These are nominally 1cm diameter, with nominally 0.5mm plate
| separation, with dielectric only between the conductive plates.
| The dielectric has a very high dielectric constant. If you resonant
| such a capacitor with, say, a 5mH inductor, you will find its
| resonant frequency will be about 70kHz. You can replace that
| capacitor with one with the same plate size and spacing but air
| dielectric, resulting in roughly 0.5pF capacitance. Then you will
| find that the measured resonant frequency depends on the self-
| resonance of the inductor, because you will be very hard-pressed to
| make a 5mH inductor with self-capacitance as low as 0.5pF. If you
| choose an inductor of, say, 1uH, properly constructed, then you
| might reasonably see the effects of 0.5pF, but now you will be
| dealing with much more awkward (especially if you have limited
| access to good test equipment) resonant frequencies in the hundreds
| of MHz. You will indeed find that the resonant frequency of that
| inductor with the nominal 1.0nF ceramic-dielectric capacitor will
| be on the order of 5MHz. The Q in each case should be high enough
| (with a well-constructed inductor) to give an easily measured
| resonant frequency. I _could_ do the experiment to specifically
| demonstrate the _dramatic_ shift in resonance, and even use other
| dielectrics less extreme, but I feel no need to: as I told you
| before, I _routinely_ design resonant circuits and filters, even
| taking into account the effects of stray capacitance and inductance
| and the resistances of things like circuit board traces where
| appropriate, and within my understanding of the tolerances of the
| parts and the effects of the strays, I'm never surprised. I am
| CERTAINLY never surprised by a resonance shifting higher as I
| increase capacitance, so long as I'm within the practical range of
| the parts I'm using.
|
| Note on 1uH coil: If you make a coil with #18AWG wire, which is
| about 1.0mm diameter, and make that coil with uniformly spaced
| turns, about 2.6cm diameter turns, spaced out 2.5cm total coil
| length, it will have an inductance about 1.0uH, and its first
| parallel self-resonance at about 190MHz. That implies about 0.7pF
| effective self-capacitance. Adding an external 0.5pF capacitance
| would drop the resonant frequency to about 145MHz.

There is nothing "surprising" at all in the letter you quote; your
correspondent is obviously an experienced engineer. Using his words to
support your assertion that the "resonance frequency of a circuit of
RLC will increase by inserting dielectric into the capacitor (without
any change of the geometry of its conductors)" would be a grave and
despicable misrepresentation. In fact he emphasizes ("I am CERTAINLY
never surprised") that he never saw deviations from textbook behavior.
Small wonder that he didn't want his name to be associated with your
imaginations; his marks of emphasis indicate that he was already
getting annoyed.

A large part of his remarks concerns the effect of stray or parasitic
capacitances and resistances: when checking capacitors by putting them
in a tank circuit, you must make sure that the capacitor under test
constitutes the dominant capacitance in the circuit, and that the
resistance and capacitance of the inductor, the resistance,
capacitance and inductance of the wiring, and the resistance and
inductance of the capacitor are all negligible.

(To some extent, the quoted passages are ambiguous because the
preceding exchange between you and him is left out and "change" or
"shift" can be read as either "increase" and "rise" or "decrease" and
"fall", etc.; the words must obviously be taken as being in accordance
with textbook behavior. And of course his "am never surprised by xxx"
must be read as "never observe xxx".)

I too am getting annoyed with your pseudo-scientific frame of mind
(read: systematic dishonesty) and am dropping off at this point.

Martin.

 

[[email protected]]

[email protected] schrieb:







There is nothing "surprising" at all in the letter you quote; your
correspondent is obviously an experienced engineer. Using his words to
support your assertion that the "resonance frequency of a circuit of
RLC will increase by inserting dielectric into the capacitor (without
any change of the geometry of its conductors)" would be a grave and
despicable misrepresentation. In fact he emphasizes ("I am CERTAINLY
never surprised") that he never saw deviations from textbook behavior.
Small wonder that he didn't want his name to be associated with your
imaginations; his marks of emphasis indicate that he was already
getting annoyed.

A large part of his remarks concerns the effect of stray or parasitic
capacitances and resistances: when checking capacitors by putting them
in a tank circuit, you must make sure that the capacitor under test
constitutes the dominant capacitance in the circuit, and that the
resistance and capacitance of the inductor, the resistance,
capacitance and inductance of the wiring, and the resistance and
inductance of the capacitor are all negligible.

(To some extent, the quoted passages are ambiguous because the
preceding exchange between you and him is left out and "change" or
"shift" can be read as either "increase" and "rise" or "decrease" and
"fall", etc.; the words must obviously be taken as being in accordance
with textbook behavior. And of course his "am never surprised by xxx"
must be read as "never observe xxx".)

I too am getting annoyed with your pseudo-scientific frame of mind
(read: systematic dishonesty) and am dropping off at this point.

Before declaring his report he asked me by email for paying him the
expences of some experiments performed by him which he claimed are
in support of the prediction of my paper. I was not able to act as he
asked me,
and continue discussion about it in usenet. Finally this dear friend
decided
to publish his report in usent which I repeated it now. That is all,
without
anythig else. He insisted that I shoud perform necessary experiments
myself and analyse the results myself. Unfortunately neither then nor
even
now, contrary to my desire, my life has not defined
based on experimental or even theoretical scientific researches.
If interested in the subject you can perform similar experiments
at least to prove decisively that this prediction is wrong.

 

[Baron]

[email protected] Inscribed thus:

I too am getting annoyed with your pseudo-scientific frame of mind
(read: systematic dishonesty) and am dropping off at this point.

Martin.

I plonked him some time ago when I realised that he was saying the text
books were wrong and he knew better !

 

[Pieter]

But if you put skis on the wheel-less car,
you do have a sled.

Pieter

 

[Paul E. Schoen]

Before declaring his report he asked me by email for paying him the
expences of some experiments performed by him which he claimed are
in support of the prediction of my paper. I was not able to act as he
asked me,
and continue discussion about it in usenet. Finally this dear friend
decided
to publish his report in usent which I repeated it now. That is all,
without
anythig else. He insisted that I shoud perform necessary experiments
myself and analyse the results myself. Unfortunately neither then nor
even
now, contrary to my desire, my life has not defined
based on experimental or even theoretical scientific researches.
If interested in the subject you can perform similar experiments
at least to prove decisively that this prediction is wrong.

I, too, would demand payment up front to perform meaningless experiments
whose outcome is predictable and not what you want to see. And, for a much
higher price, I might be willing to report (falsified) findings that are
favorable to your assertations, but as that would completely destroy any
credibility I might have, it would be a very high price indeed.

But the experiment you describe is not that difficult to do. As described
elsewhere, you can just read the capacitance of a multiple plate air tuning
capacitor, insert dielectric sheets, and measure again. Capacitance will
increase. If there had been a charge on the plates, the voltage will
decrease. If you connect the capacitor to a battery, and insert the
dielectric, you can measure current flow out of the battery as you do so,
which means that the battery is acting as a source of potential. Now, if
you can charge the battery by performing this action, then you might say
the dielectric, or rather its motion caused by your application of external
force, is the source.

This is a perfect "mental experiment" as Einstein enjoyed doing, which
required nothing more than his mind and a solid basis in scientific
methods, facts, mathematics, and a good dose of imagination. He also
regularly smoked a pipe. To make this mental experiment meet the OP's
expectations, something more than tobacco would be necessary!

Paul