pc1mb schreef:Laat ik dan maar
het Wikipedia-commentaar op de demonteerbare Leidse fles erbij voegen:
When not properly explained, this demonstration promotes the myth that capacitors store their charge inside their dielectric. This erroneous theory, due to Franklin, was taught throughout the 1800s, and is still sometimes encountered. However this phenomenon is a special effect caused by the high voltage on the Leyden jar.[7]In the dissectible Leyden jar, charge is transferred to the surface of the glass cup by corona discharge when the jar is disassembled; this is the source of the residual charge after the jar is reassembled. Handling the cup while disassembled does not provide enough contact to remove all the surface charge. Soda glass is hygroscopic and forms a partially conductive coating on its surface, which holds the charge.[7] Addenbrook (1922) found that in a dissectible jar made of paraffin wax, or glass baked to remove moisture, the charge remained on the metal plates.[8] Zeleny (1944) confirmed these results and observed the corona charge transfer.[9]In capacitors generally, the charge is not stored in the dielectric, but on the inside surfaces of the plates, as can be seen from the fact that capacitors can function with a vacuum between their plates.
Case closed, nietwaar? Al zul je het met de laatste paar woorden misschien niet eens zijn, maar dat maakt voor de rest van het verhaal niet uit.
Not so fast, my friend!
Laten we eens kijken naar dielectrische relaxatie, het spontaan herladen van condensatoren:
http://citeseerx.ist.psu.edu/viewdoc/do ... 1&type=pdf
1.0 Introduction
A fundamental limitation in the accuracy of sample-and-holds and A-D converters is a phenomenon called dielectric absorption, which also goes by the names of dielectric relaxation and soakage [20]. Dielectric absorption is the tendency of a capacitor to recharge itself after being discharged. While not widely appreciated, dielectric absorption is also the dominant loss model over the entire usable range of most capacitors, andso can also affect the performance of high-Q circuits such as VCOs. This paper covers the symptoms of dielectric absorption in both the time and the frequency domains, the physical mechanism that causes it, and the process of modeling it.
2.0 Symptoms
If a capacitor remains charged for a long period of time and then is briefly shorted, the voltage on the capacitor will slowly tend to recover to a fixed percentage (typically between 0.01% and 10%) of its original value. This percentage is a simple measure of dielectric absorption. The amount of dielectric absorption a capacitor exhibits is highly dependent on the dielectric material: polystyrene, polypropylene, and teflon display very little absorption, while ceramic is a much poorer performer. SiO2 displays about 0.1% dielectric absorption, putting its performance in the middle of the pack [12,16]. Recovery that results from dielectric absorption can be simply modeled.
Het heeft er alle schijn van dat je dit relaxatie-effect in "high gear" kunt krijgen door je (electrolytische) condensator te voeren met hoog voltage spikes:
http://www.youtube.com/watch?v=LuCg2BQfPUQ
http://www.youtube.com/watch?v=CwTnt3P9OCY
Dus: je sluit je condensator kort, waarbij de lading verondersteld wordt zich op de platen te bevinden die na het kortsluiten dus weg is, en vervolgens blijkt het ding vanzelf spontaan te herladen, terwijl er dus een isolator (het dielectricum) tussen de platen zit...
Hmmm.
Meer in mijn eerder gerefereerde artikel:
http://peswiki.com/index.php/Article:Fr ... ret_Effect
Moet er bij vermelden dat ik dit al geruime tijd geleden geschreven heb. Ik denk nu in de richting dat atoomkernen en electronen, hetgeen een of andere staande EM golf is, in feite bestaat uit een zeker aantal vortexen in de ether. En die vortexen zijn een soort ether-pompen. Op die manier wordt dus energie vanuit de ether (ZPE) omgezet in een of andere steady-state flow van ether: een statisch electrisch veld. Die ether flow staat dus helemaal los van het al dan niet stromen van electronen. Met andere woorden: er zijn twee separate energiestromen waar we rekening mee moeten houden:
1. electronen die door een draad of component bewegen
2. de etherstromen rondom/door de componenten die de electronen voortbewegen.
Een gepolariseerd dielectricum geeft volgens mij het effect dat de zich in het materiaal bevindende "ether pompen" een steady-state etherflow tot gevolg hebben *zonder* dat daarbij electronen door het materiaal stromen.
Het is deze etherflow die kennelijk in staat is electronen door het dielectricum te laten driften en op die manier zowel elco's als batterijen spontaan op te laten laden, *mits* ze zodang "geconditioneerd" zijn dat het dielectricum voor langere tijd gepolariseerd blijft.
En kennelijk vertoont glas een soortgelijk effect.
Dollard heeft naar mijn mening in dit geval geen gelijk. Er wordt geen energie opgeslagen in het dielectricum. Het materiaal polariseert, hetgeen betekent dat de "ether pompen" in het materiaal een iets andere richting uitblazen, waardoor er netto een steady-state etherstroom door het materiaal stroomt wat we vervolgens een statisch electrisch veld noemen. Daar komt uiteindelijk de energie vandaan, maar dit is een dynamisch proces, waarbij er continu energie vanuit de omgeving wordt omgezet in een steady-state beweging in de ether.
Zie Turtur e.a. zoals gequote in mijn artikel:
Well, it may be right that particle physics says it's easy to extract EM energy from the vacuum, but that does not tell us how we can use that, nor how we can engineer systems that are able to make use of this unknown, or better: overlooked, territory. Where is that energy? Where does it come from and where does it go?
The answer to these questions can be found in the paper Conversion of the Vacuum-energy of electromagnetic zero point oscillations into Classical Mechanical Energy by the German Professor Claus Turtur. In the chapter "A circulation of energy of the electrostatic field" (pages 10-14) he makes a straightforward calculation of the energy density of the static electric field surrounding a point charge using nothing more than Coulombs law and the known propagation speed of the electric field, the speed of light, and shows that there must be some kind of energy circulation between the vacuum and charge carriers:
If electrostatic fields propagate with the speed of light, they transport energy, because they have a certain energy density. It should be possible to trace this transport of energy if is really existing. That this is really the case can be seen even with a simple example regarding a point charge, as will be done on the following pages. When we trace this energy, we come to situation, which looks paradox at the very first glance, but the paradox can be dissolved, introducing a circulation of energy. This is also demonstrated on the following pages.
The first aspect of the mentioned paradox regards the emission of energy at all. If a point charge (for instance an elementary charge) exists since a given moment in time, it emits electric field and field’s energy from the time of its birth without any alteration of its mass. The volume of the space filled with this field increases permanently during time and with it the total energy of the field. But from where does this “new energy” originate? For the charged particle does not alter its mass (and thus its energy), the “new energy” can not originate from the particle itself. This means: The charged particle has to be permanently supplied with energy from somewhere. The situation is also possible for particles, which are in contact with nothing else but only with the vacuum. The consequence is obvious: The particle can be supplied with energy only from the vacuum. This sounds paradox, so it can be regarded as the first aspect of the mentioned paradox. But it is logically consequent, and so we will have to solve it later.
[...]
Important is the conclusion, which can be found with logical consequence:
On the one hand the vacuum (= the space) permanently supplies the charge with energy (first paradox aspect), which the charge (as the field source) converts into field energy and emits it in the shape of a field. On the other hand the vacuum (= the space) permanently takes energy away from the propagating field, this means, that space gets back its energy from field during the propagation of the field. This indicates that there should be some energy inside the “empty” space, which we now can understand as a part of the vacuum-energy. In section 3, we will understand this energy more detailed.
But even now, we can come to the statement:
During time, the field of every electric charge (field source) increases. Nevertheless the space (in the present work the expressions “space” and “vacuum” are use as synonyms) causes a permanent circulation of energy, supplying charges with energy and taking back this energy during the propagation of the fields. This is the circulation of energy, which gave the title for present section 2.2.
This leads us to a new aspect of vacuum-energy:
The circulating energy (of the electric field) is at least a part of the vacuum-energy. We found its existence and its conversion as well as its flow. On the basis of this understanding it should be possible to extract at least a part of this circulating energy from the vacuum – in section 4 a description is given of a possible method how to extract such energy from the vacuum.
So there we are. The electric field (the airflow in our fandoor analogy) is on the one hand powered by the vacuum and on the other hand it powers the vacuum. So, at least part of the energy in space / the vacuum, referred to with names as "Zero Point Energy" (ZPE), virtual particle flux, the Dirac sea, Orgone, etc. is not only fueled by the electric field, it is continuously converted back into an electric field by each and every charged particle in the universe, which makes the electric field a source of energy. The implications of that are staggering. It means that the law of conservation of energy does not apply to electrical systems, because they are not isolated. After all, Turtur shows without a shadow of a doubt that energy is being extracted from the active vacuum by each and every charged particle and thus every electrical system in existence in the Universe.
Interestingly, Nikola Tesla already said the exact same thing in 1891:
Nature has stored up in the universe infinite energy. The eternal recipient and transmitter of this infinite energy is the ether. The recognition of the existence of ether, and of the functions it performs, is one of the most important results of modern scientific research. The mere abandoning of the idea of action at a distance, the assumption of a medium pervading all space and connecting all gross matter, has freed the minds of thinkers of an ever present doubt, and, by opening a new horizon—new and unforeseen possibilities—has given fresh interest to phenomena with which we are familiar of old.
Based on all this, it is clear that we need to look at electrical systems in a different way, we need a way of thinking that does account for the energy source that is really powering our systems. In a way, we need a similar change in our models as the change from Newton to quantum mechanics. While Newtonian mechanics can still be used in mechanical engineering most of the time, at some point they are no longer valid, for example in the calculation of satellite orbits. In the same way, the current electrical engineering model is fine for most applications where it suffices to consider only the door part of our fandoor analogy, that is, by considering electrical systems basically as an analogy of hydraulics, which is literally just a variation of Newtonian mechanics. However, if you want to be able to utilize the energy source the electric field provides, there just ain't no way to do that without taking the energy exchange between an electrical system and the vacuum completely into account. And that means we have to go back to field theory instead of describing our systems in terms of concrete components, the so-called lumped element models, especially in the case we are dealing with resonating coils. This is explained by James and Kenneth Corum points in Tesla Coils and the Failure of Lumped-Element Circuit Theory:
In the following note, we will show why one needs transmission line analysis (or Maxwell's equations) to model these electrically distributed structures. Lumped circuit theory fails because it's a theory whose presuppositions are inadequate. Every EE in the world was warned of this in their first sophomore circuits course.
All those handbook formulas that people use for inductance, L, inherently assume applications at frequencies so low that the current distribution along the coil is uniform. The real issue is that migrating voltage nodes and loops are not a property of lumped-circuit elements - they are the directly observable consequence of velocity inhibited wave interference on the self-resonant coil. Lumped element representations for coils require that the current is uniformly distributed along the coil - no wave interference and no standing waves can be present on lumped elements.
So, we need to consider the fields and that also means we need to realise that the nature of these fields is dynamic and not static. In the old Newtonian model, we consider the voltage across an impedance to be the cause for a current to occur, which in our fandoor anology would be the pressure that the door "feels" being enacted by the airflow on its surface, while in reality it is the airflow (the electric) field that acts upon the door and not the pressure itself. In other words it seems like the "pressure" the electric field enacts on our components is static, hence the name "static electric field", while in actual reality this force is a dynamic force, something flows along the surface that creates the pressure. Tesla already realised this in [1892]:
There is no doubt that with the enormous potentials obtainable by the Use of high frequencies and oil insulation luminous discharges might be passed through many miles of rarefied air, and that, by thus directing the energy of many hundreds or thousands of horse-power, motors or lamps might be operated at considerable distances from stationary sources. But such schemes are mentioned merely as possibilities. We shall have no need to transmit power at all. Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe. This idea is not novel. Men have been led to it long ago by instinct or reason; it has been expressed in many ways, and in many places, in the history of old and new. We find it in the delightful myth of Antheus [Antaeus], who derives power from the earth; we find it among the subtle speculations of one of your splendid mathematicians and in many hints and statements of thinkers of the present time. Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature.
Overigens propageert het statische electrische veld met een snelheid van pi/2 x c, zoals gemeten door Wheatstone:
http://www.tuks.nl/pdf/Reference_Materi ... 0Light.pdf
The deviation of half a degree between the two extreme sparks, the wire being, as above stated, half a mile in length, would indicate a velocity of 576,000 miles in a second. This estimated velocity is on the supposition that the electricity passes from one end of the wire to the other: if, however, the two fluids in one theory, or the disturbances of equilibrium in the other, travel simultaneously from the two ends of the wire, the two external sparks will keep their relative positions, the middle one will be alone deflected, and the velocity measured will be only half that in the former case, viz. 288,000 miles in a second.
Ondanks deze experimentele resultaten wordt daar tegenwoordig overheen gepraat alsof de natuur zich dient te gedragen naar onze theorieën en niet andersom:
http://en.wikipedia.org/wiki/Charles_Wheatstone
Velocity of electricity
He achieved renown by a great experiment — the measurement of the velocity of electricity in a wire. He cut the wire at the middle, to form a gap which a spark might leap across, and connected its ends to the poles of a Leyden jar filled with electricity. Three sparks were thus produced, one at either end of the wire, and another at the middle. He mounted a tiny mirror on the works of a watch, so that it revolved at a high velocity, and observed the reflections of his three sparks in it. The points of the wire were so arranged that if the sparks were instantaneous, their reflections would appear in one straight line; but the middle one was seen to lag behind the others, because it was an instant later. The electricity had taken a certain time to travel from the ends of the wire to the middle. This time was found by measuring the amount of lag, and comparing it with the known velocity of the mirror. Having got the time, he had only to compare that with the length of half the wire, and he could find the velocity of electricity. His results gave a calculated velocity of 288,000 miles per second, i.e. faster than what we now know to be the speed of light, but were nonetheless an interesting approximation.
It was afterwards found that the velocity of an electric field travelling in a cable depends on the nature of the conductor, its resistance, and its electro-static capacity. Michael Faraday showed, for example, that its velocity in a submarine wire, coated with insulator and surrounded with water, is only 144,000 miles per second (232,000 km/s), or still less. Wheatstone's device of the revolving mirror was afterwards employed by Léon Foucault and Hippolyte Fizeau to measure the velocity of light.
Tja, wederom het verschil tussen transversale en longitudinale golven c.q. (steile) pulsen dat even onder het vloerkleed gemoffeld wordt... Zowel bij pulsen als longitudinale golven propageert de ether rechtuit, terwijl bij transversale golven een omwegje van (netto) een halve cirkel genomen wordt. Vandaar de factor pi/2. Wanneer we Wheatstone's 288,000 delen door 186,282 komen we op 1,54. Verdraaid dicht bij de theoretische 1,57, zeker gezien de omstandigheden waaronder Wheatstone zijn metingen deed...
Interessant detail is dat Wheatstone dus de propagatiesnelheid van pulsen door de lucht heeft gemeten, terwijl Dollard's metingen longitudinale golven betrof. Dollard meette hierbij 1,25 x c, terwijl Wheatstone dus 1,54 x c mat. En daarmee wordt duidelijk dat het electrische veld dat de ladingsdragers voortstuwt zich in feite *buiten* de draad bevindt en voortplant....
"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong." - Arthur Charles Clarke -
