Wireless Power? (The work of Nikola Tesla)

sophiecentaur

Can you tell me how the volts on the 100Ω, R1 resistor is telling you the Power input to the Coil? If you do not know the input impedance then you cannot know the Forward Power All you can tell is the power dissipated in the 100Ω resistor. (Which you need for a measure of real efficiency) As I said before, measuring RF power into a load is not trivial. You do not know the power delivered by your signal generator or the power into the load. You are misleading yourself if you infer too much from your Voltage Measurements.
Also, have you used two 'secondaries' and verified what you have told me about the sharing of (most of) the power between them? That would be a good indicator of whether or not your conclusions hold water.

I do not doubt that you are getting some measurable coupling but I have difficulty in accepting that it could be as high as you think it is.

It wouldn't be difficult to squeak those coils and to get an idea of the Q involved.
If you really want to test whether or not there is 'Radiative Power' involved, you could use a receiver at a distance and see how the signal level received behaves with and without your 'secondary' circuit.

Meizirkki

Yes, I have tried that with my coils in Finland and the pancake coils here. Sadly all attempts to use the the ground mat and PE ground have failed. I don't know why, but it may have something to do with the tuning of the coils since whatever is connected to them is a part of them. Another problem may be that this mesh of wires is sitting in the air and has so large capacitance to the upper end of the coils that it affects the transmission.

Overall, the ESD protection in that room is a usually a big problem for testing the coils. In the above pictures only half of the receiver is over the table. This is not a random placement but necessary for the transmission. Also, the water container is on a cardboard box, this is also required, as putting it on the table would greatly reduce the output.

Everything needs to be done with great care for things to work :)

EDIT: please wait a bit I will respond to your latest post asap.

sophiecentaur

RE Post 70

The connecting wires are clearly contributing to the resonance and they introduce a huge unknown into any analysis. It goes without saying that operating on an earth mat would involve re-tuning - perhaps to a very high degree.

Meizirkki

No, I have not tested it with Tesla coils. But I have noticed the power sharing effect in the near field of joule thief circuits involving coils. (Very similar to Tesla coils). When I bring a fluorescent bulb next to the coil it is lit brightly, but when another bulb is brought next to it, the brightness in the first one will reduce and both bulbs will equally share the power from near field. But yes, I will have to test this with Tesla coils too.

Good idea, I will keep that in mind.

Here's a complete explanation of my calculations in the document:
*Internal resistance of the oscilloscopes (1Mohm) are not taken into account in any of the calculations.

I hope this clears things up, if there are any errors please let me know and I will correct them.

sophiecentaur

I am now starting to get a better picture of what you are doing. The spacing is a little under a wavelength, which is near field - no one would suggest this is 'radiative coupling' so it is reasonable to talk of 'inductive coupling' but also in terms of how a transmission line works. I imagine that the whole set up would be 'fairly lively' and would be susceptible to the routing of this connecting wire. I must say, this is a very worrying part of the set up, in terms of understanding its function in the whole set up. Being just short of a wavelength, the phase of current flowing in it could be affected by the geometry of surrounding conductors (it constitutes an unbalanced transmission line of unspecified impedance)

I don't understand why you talk in terms of ESD in this context. It is not ElectroStatic because it is all at RF - which is Alternating. If the primary voltage you excite the coil with is high enough then there will be non-linear arcing effects which constitute a large resistive loss (hot plasma wastes power). There should be no reason why you should have a problem in plotting a parallel resonance (High Z) at around the centre frequency. (Using a high source resistance would sharpen up the resonance of a coil on its own. If both coils are identical then the resonances should coincide. This assumes that the earthy end of the coils is well grounded. Anything else 'hung on' the circuit (in the form of this connecting wire) will affect the resonance and add an unknown to the system. The reason that you are finding difficulty in measuring resonance and Q will be because you are working with high impedances and Parasitics will show themselves everywhere. (Most RF work is done on 50Ω systems because parasitics are of less consequence).

In fact, when you get down to it, if you simply connected the two primaries together via a series capacitor and a long wire, you would have a simple unbalance transmission line, which should transmit fairly efficiently, in its own right, particularly if you incorporate some matching network at each end to match source and load to a line which would (as with all such unbalanced lines) have a characteristic impedance in the order of a couple of hundred Ohms.

Meizirkki

I was referring to the "ESD protection" in the area where I work. Every single thing in the room from trash cans to our clothes are EPA equipment which means there are indeed lots of conductors around the coils to mess things up. When operated at frequencies "higher than resonance" the coils have rather large field around them. We have an eletrostatic field meter here to measure it. It's very interesting.

You are right, the whole thing could be much more simple, but I can see several reasons why tesla used the kind of setup he describes in his patents. It allows for higher voltages, higher storage of energy and longer distances. (methinks)

sophiecentaur

How is there an electroSTATIC field? Where does it come from? Is it due to some rectification effect caused by the arcing? What are your clothes and trash cans 'messing up"?

I do not understand why 'storage of energy' is relevant here. Could you explain?

You have not explained why the transmission of the RF power is not simply by virtue of the fact that you have an unbalanced transmission line connecting the two coils. That explanation holds water.

Please disregard the existence of patents. They imply nothing about the validity of the Science involved or that the patented device could work or has ever worked.

You are disregarding something much more relevant and that is basic EM theory, which has been round the block many times since Tesla was doing his stuff. I know which I would put my money on.

The magnetic fields that you are basing your ideas on must be measurable and quantifiable theoretically. The way fields behave near radiators is different to how they behave in free space. All you have experimented with has been near field and you cannot just extrapolate to the far field. Do you not believe in Maxwell's equations and all the established antenna theory? You would be very brave to argue against it all.

Meizirkki

No updates, but I'm dropping by to admit my claim of electrostatic fields around coils was total bs. I tested it again and got absolutely nothing. Sorry.

I was attempting to power the coils with HV peaks using influence machine + spark gap. It was this experiment that failed and instead of making the coils oscillate, charged them to high potentials. I confused the measurements from this test to the earlier ones and that's why I said such nonsense.

I started a new thread for a question that has been in my mind for some time. Electric fields form at both sides of the dielectric and I wonder if the change in field can appear faster than light travels the distance between plates. Many people say that Tesla claimed his radio to be faster than light.

EDIT:

In a practical setup for transmission of power the ability to store energy in an oscillating field will come in handy.

I did not object when you made your statement. I have nothing to explain.

jim hardy

If you've not seen it already, you might enjoy this guy's article about Tesla and one wire transmission. But you'll have to brush aside his editorializing.

ARRL antenna handbook mentions the "waveguide" formed by earth's surface and ionosphere. Tesla might have got overzealous about its possibilities.

http://amasci.com/tesla/tmistk.html

Meizirkki

Thank you for the link. A very interesting article indeed, though I do not agree that the Earth is used as a conductor in Tesla's system. (or that the ionosphere has any function in the system)

ElectricJames

Im doing the same research and this is the reason why I registered in this forum. I think you already hadn't read the report by Tesla where he explains that wireless must not be just electromagnetic waves but high speed metal particles (40 times the speed of sound). The article is called "THE NEW ART of PROJECTING CONCENTRATED NON-DISPERSIVE ENERGY THROUGH NATURAL MEDIA" where he explains himself some detaild of the "open vacuum tubes", where the vacuum were generated continously and giving the possibility to make a window to eject some small high speed metal particles like tungsten, mercury or other metal and and were repulsed by electrostatic force and directed by UV rays, giving conductivity to the air. I never seen anybody on internet experimenting with it. I really believe that everything that were invented by Tesla worked very well and had some use for the same one propose: make war impossible.
The hurted pigeons that he were taking care on the street maybe some idea to avoid to the goverment secret investigation to use healthy animals on their usual tests. I think that the death ray existed and it may developed by the goverment helped by Nickola.
The only good information that you would find are the books and reports that he himself wrote like "My inventions", "Complete U.S Tesla patents" and much other documents around internet, and maybe other ppl who is doing the same research. By now Im searching information about how to make up vacuum tubes and cathode ray tubes using Buchner flask and vacuum generator, or air compresor using Tesla's fused quarz valve.
Im searching ppl to share information and knowledge about risks and caution, concepts, acad projects about Tesla inventions and fit all the possiblities, ideas and mistakes together to see if we get some mistery solved.

I seen many "wireless" experiments but I still never seen any experimenter on youtube or anywhere electrifying the ground and beeing able to connect bulbs on it... But Im sure it must be possible as it happends with underground water.

ElectricJames

Tesla coil is not a transformer, cuz the primary and the secondary are separated by air, and the transformers need ferromagnetic core. If you dislike his ideas is just bcz you don't know about too much him. Marconi was a rat who robed an small part of Tesla's patent to make money and destroying all his plans (and Tesla won the judgment), and same as Edison tryed to do with the invention of the "electric chair" (this is why I think that the mainstream of science is rubish giving wrong information to the children like TV). You are giving credit to someone who invented a bulb with filament and a not usefull radi patent. You just don't take care about who invented alernate current, triphase generator/motor, induction motor, radio, radiocontrol, radar, comertial lighting tube, the first who experimented with X rays (I should make a long list but I have no time). And his best claim was the wireless energy and not using just radio waves but high speed metal particles, giving conductivity to the air and driving it with UV rays. I don't understand why most ppl just tell their opinion without knowing and that the world system of education is still telling simply LIES even knowing that Tesla had a radiocontrolled boat many years beore all this cheeky bastards. Edison believed himself that he invented a machine to speak with spirits, did you knew that? And Marconi lost the judgement for the ptent of radio against Tesla but the it still appears Marconi and this is a lack of respect.

I reccomend to search for this article:
w x 3 (dot) tfcbooks(dot)com/tesla/1935-00-00(dot)htm

Meizirkki

jim hardy, thank you for posting that link earlier. Things are getting more and more clear everyday. The water experiment made me think it cannot be a single conductor system, but later tests show that the two wires in water can not be too far apart, or the transmission will fail. So I think what you say is right.

I find Tesla's particle beam weapon interesting too. Has anyone else ever attempted to build an open vacuum tube? The results would sure be interesting, but that topic deserves it's own thread.

sophiecentaur

To work at mains frequency requires a ferromagnetic core. The basic theory of transformers does not specify the permittivity of the medium used for the coupling.

Meizirkki

It's been so difficult to find any information about Tesla's system from Tesla himself. Here's some:
http://www.tfcbooks.com/tesla/nt_on_ac.htm

And for me it clears things quite a lot. Capacitive coupling indeed has no role in the system, except in the near field.

Let's imagine a following scenario: We drive a big tesla coil by creating and collapsing a magnetic field on the coil. The collapsing field creates a current on all parts of the system; The coil itself, the upper terminal, and the earth. With few hundred million volts the earth's resistance is no longer a killer for the transmission, but rather a very big "wire". There's also talk about the ionosphere.

At low enough frequencies, the energy is hardly radiated away from the system, but contained in the oscillating field, like it can be contained in any coil. No one has ever attempted to replicate this on the same scale. Is there any reason why this kind of system _could not_ work?

nsaspook

Wires are cheaper and are better at moving power using any practical power distribution frequency. Wireless power has it's place but why would you need it in a normal house to run the toaster?

Meizirkki

If humanity had any sense of doing things right, we would still be hunter-gatherers free of the "how to run my toaster" -problem.