Wireless Power? (The work of Nikola Tesla)

In summary, Nikola Tesla was a brilliant inventor who was able to wirelessly power light bulbs. His work has always fascinated me. However, I'm finding it hard to find any reliable sources on his actual experiments. I'm looking for more in-depth information on what he actually managed to accomplish. If anyone knows of any reliable sources, please let me know.
  • #36
sophiecentaur said:
Never upset - don't worry.
My point is that your 10Ohm resistor measurement will not tell you the power unless you know source and load impedances. If you have resonant systems it is even less easy. So, apart from the fact that you lit your diodes, you cannot know the efficiency.

But there are two entirely separate issues here. You have shown that it is possible to get good coupling between a source and load, using a transformer but that has nothing to do with the notion of getting energy from other, unspecified, sources of RF energy. You did not take my point about Conservation Laws, but they apply here the same as anywhere else and they are the basic objection to 'excess energy' and also to this. Going back a bit, you are actually suggesting the equivalent to a 'Maxwell Demon', which has been put to bed long ago.

In my last two posts I have apologized for causing all these misunderstadings by not making my posts clear enough. No, it's not that. I read several previous posts of mine and I don't understand which part of them makes you think that:

- I am not familiar with the laws of thermodynamics and the conservation of energy.
- I have claimed that my coils would "collect energy"

I never claimed that Tesla coils had something to do with "collecting energy" nor did I make the slightest implication that my coils were in any way associated with the whole subject.

I didn't comment on your point about energy conservation laws and thermodynamics because I wasn't ignorant to them in the first place. You say that I was "suggesting the equivalent to a 'Maxwell Demon'".. I do not recall making such a suggestion.

Also, I must say I am slightly offended by your refusal to believe that I and the teachers of my school know how to measure efficiency.
 
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  • #37
Rather than saying the coils 'collect energy' it would be more appropriate to say that the 'couple energy' from one to another. That is a mutual effect involving 'near fields' and your receiving coil is getting its energy from a relatively high power source nearby. This is nothing to do with Mr Tesla but is good fun and a worthwhile experiment / demo.
Any structure will receive RF energy and radiate it in the same way that it will absorb and radiate thermal energy, in fact it's the same thing. The net gain or loss of energy will depend upon the total energy from all outside sources and the noise energy generated naturally within the structure due to the energy stored in it. It makes no difference whether you have a high Q or low Q, the totally energy available 'to use' from the receiving structure will just be equal to the flux of energy it can intercept. Any excess energy will be re-radiated. If you consider that the total amount of noise and interference energy (unless you happen to live just down the road from a powerful transmitter) passing through the area intercepted by a small antenna (or any structure) will be such that it will need amplification before it's easily detectable. Crystal sets are operating with relatively powerful signals and are the only 'passive' receivers you can make. These only make use of a mW or less of energy, from one or more powerful mf transmitters,not too distant. The net energy from all transmissions is of no use for powering any device but a sensitive earphone. No useful free energy. You would need to specify what other 'sources of energy' could provide any more than this. Magnetism is not a source of energy any more than the Earth's gravitational field is, on its own.

I question your measurement of efficiency because what you have described is not a valid way to find it.

Your contributions imply a connection between Tesla (you have championed his cause) and the results of your experiments. If there is no connection then perhaps a separate thread would have been better.

Your response to my objection involving Conservation Laws implies that you do not see the bigger picture and where they come into play.
 
  • #38
Hello again. I have a work trip to germany the next month, so I hurried to finish my new coils and take measurements before that.

Unfortunately for me, the efficiency was not at all what I expected. At first I couldn't believe my own calculations, since the results were so much better with the old coils. I checked photos of the earlier experiment and BUM. I found that in the earlier experiment, I had accidentally connected the scope probe in a way that short circuited the resistor I was measuring voltage from. :uhh: The fact that both funtion generator output and scope probe are connected via PE ground had apparently crossed my mind. Thanks to the PE ground being such poor conductor for HF signal I still got results and considered the experiment a huge success.

https://docs.google.com/document/d/1QirnU-yX7XPJY_1MaW0UqU-egkO3-6WoxhcDQ3yiOyE/edit?pli=1

Thinking about it now, I find my own claim of 95% efficiency absurd. More than 5% is certainly lost already in the induction between the primary and the secondary. bah. I feel so stupid for not seeing that myself. Sorry.

My new coils aren't a complete failure though. Even with notable inconsistencies in the coils and sinewave input, the transmission did work. The efficiency, while being only a fraction of my previous claim, could never be achieved with magnetic induction at that distance (I tried that too), and with major improvements to design will definitely challenge radio transmission esp. at longer ranges. (correct me if I'm wrong)

At the very last, I hope this experiment provides enough evidence to show Tesla's transmission system is not "all moonshine".

I'm looking forward to improving the coils and designing a solid state power supply for the transmitter. Apart from improving the efficiency, I'm going to test whether distance has any effect on the transmission. If I can find faraday cages I will place the coils in them just to show the transmission is not based on EM waves and all energy radiated is energy lost.

Peace.
 
  • #39
Meizirkki said:
At the very last, I hope this experiment provides enough evidence to show Tesla's transmission system is not "all moonshine".

I'm looking forward to improving the coils and designing a solid state power supply for the transmitter. Apart from improving the efficiency, I'm going to test whether distance has any effect on the transmission. If I can find faraday cages I will place the coils in them just to show the transmission is not based on EM waves and all energy radiated is energy lost.

Peace.

Why should the basic working of a transformer system be attributed to Tesla? You may as well attribute it to Faraday - the only difference is the Iron core and the frequency.

I don't see why you would need a Faraday cage if you're planning to achieve 90% efficiency. Why should you care where the odd 10% is going? If you put it in a metal box, they you have even less idea about how the coupling is achieved and it would barely qualify for the name 'wireless' - more like a waveguide.

If you are using the separation distances that are referred to in 'that paper', you will be in the near field, in any case, so it won't be the radiated power but the 'coupled' power. When you say that it's not based on em waves, I'm not sure what you can mean. Do you mean 'free waves'? Because, if the power is not transferred by electromagnetism then you would have to invent a new set of fields to account for it. Is that feasible?

I can see that you think I am being a 'wet blanket' concerning Mr Tesla but do you not consider the possibility that you are re-inventing a wheel that has been re-invented many times before (including Tesla). If you want to optimise performance then you really need to look into the matching problem and what is basically an Impedance Matrix involving the self and mutual impedances of the two structures. Do some reading round and, apart from the term 'wireless' that has been hijacked recently, this sort of thing has been looked at many times. The difference in the situation these days is mainly the availability of cheap and efficient amplification and rectification and low power requirements for modern electronic equipment - which is probably why it is taking off again.

BTW, my ageing rechargeable toothbrush uses Wireless Power - but, as it's at 50Hz and needs to be small, the distance involved is not great.
 
  • #40
sophiecentaur said:
Why should the basic working of a transformer system be attributed to Tesla? You may as well attribute it to Faraday - the only difference is the Iron core and the frequency.
I'm only talking about Tesla all the time because this thread is about him and it's his work I'm trying to replicate. It's not my purpose to praise Tesla.

sophiecentaur said:
I don't see why you would need a Faraday cage if you're planning to achieve 90% efficiency. Why should you care where the odd 10% is going? If you put it in a metal box, they you have even less idea about how the coupling is achieved and it would barely qualify for the name 'wireless' - more like a waveguide.
I would do that only to show the energy is not transferred via radio waves.

sophiecentaur said:
If you are using the separation distances that are referred to in 'that paper', you will be in the near field, in any case, so it won't be the radiated power but the 'coupled' power. When you say that it's not based on em waves, I'm not sure what you can mean. Do you mean 'free waves'? Because, if the power is not transferred by electromagnetism then you would have to invent a new set of fields to account for it. Is that feasible?
Sorry, I'm confusing terms again. By EM waves I meant radio waves. I'm curious to how large this near field is, and how far it could be "stretched" with higher voltages and Earth grounding. And I forgot to mention, but that paper was made by me.

sophiecentaur said:
I can see that you think I am being a 'wet blanket' concerning Mr Tesla but do you not consider the possibility that you are re-inventing a wheel that has been re-invented many times before (including Tesla). If you want to optimise performance then you really need to look into the matching problem and what is basically an Impedance Matrix involving the self and mutual impedances of the two structures. Do some reading round and, apart from the term 'wireless' that has been hijacked recently, this sort of thing has been looked at many times. The difference in the situation these days is mainly the availability of cheap and efficient amplification and rectification and low power requirements for modern electronic equipment - which is probably why it is taking off again.
I might be reinventing a wheel that has been reinvented many times but I don't mind it. Even though the near field coupling is widely known and used, I haven't found anyone trying to do the same over long distances with the help of Earth and atmosphere. The only way to find out whether "Tesla was right" is to try do it myself.

With this more specific testing I've come to notice the same thing you say, the impedance and top/self capacitances of the coils should be exactly the same to achieve the best performance, but it's rather hard to do. It was obvious to me that my coils were somewhat out of tune when the output power could be improved by bringing my hand near the transmitter. I was tempted to take results while holding my hand there but I couldn't see the reading of output voltage on the other side of the room :tongue:
 
  • #41
uhh I meant to say inductance, not impedance. (can't I edit my posts?)
 
  • #42
The problem with wireless power transmission is that you lose an awful lot of power through leakage to the atmosphere. Tesla could transmit power from one end of a stage to the other but not much further. (That's why "electrical engineering" used to be referred to as "power engineering" and "electronic engineering" as "signal engineering".)

The problem of loss is less with microwaves but there are other problems (it is far more dangerous to stand in front of a microwave beam than in front of a radio beam).
 
  • #43
HallsofIvy said:
The problem with wireless power transmission is that you lose an awful lot of power through leakage to the atmosphere. Tesla could transmit power from one end of a stage to the other but not much further. (That's why "electrical engineering" used to be referred to as "power engineering" and "electronic engineering" as "signal engineering".)

The problem of loss is less with microwaves but there are other problems (it is far more dangerous to stand in front of a microwave beam than in front of a radio beam).

That's just not true. Tesla transmitted power over a hundred and fifty mile radius. He invented fluorescent lighting tubes that he placed on farms and ranches so he could monitor the transmission. These tubes were placed as far as 150 miles away from his tower and were to be witnessed by the farmers and ranchers. Tesla was hoping that the power transmission would extend at least 100 miles but tubes 150 miles away lit up. I have not read where he ever commented on how far the power could reach.
 
  • #44
You would have to provide substantial evidence than that about your claim about Tesla's demonstration. It's such an outrageous claim that you would need a lot more than some lines from a book.
It just has to be nonsense or you'd have to reject everything from Maxwell onwards in order to believe it.
This is supposed to be a Scientific discussion with its feet firmly on the ground and not fantasy.
 
  • #45
Meizirkki said:
uhh I meant to say inductance, not impedance. (can't I edit my posts?)

Is there not an Edit button at the bottom of your posts? I can always find one on my latest posts. It's on the same line as the 'Quote' button.

Yep - this is an edit.
 
  • #46
I've seen the button. I guess it just disappears after a while since I can't edit any of my posts now.

EDIT: Except for this one I just made. ;)
 
  • #47
An Australian inventor is claiming to have found the solution to Tesla's Underground Wireless Transmission and is looking for input from experienced people in this field.
They are encouraging Universities to get involved by building a cost effective apparatus to demonstrate "proof of principle"
There is a google blog link in the "Serious activities Begins" section on the home page

[crackpot link deleted]
 
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  • #48
When that "Australian Inventor" has some theory or results to publish then I'm sure PF will be all eyes and ears. Until that, it's still Science fiction (by definition) and is not a part of PF world.

btw, only one conductor is needed to carry a guided wave. I thought simply everyone had heard of a Goubeau Line. That link doesn't seem to have heard of it, yet they're pontificating about 'earth return'. Probably not a good source of serious info.
 
  • #49
Solution? Pff. Like there ever was a problem? :P

EDIT: How on Earth is this something "that no one has ever been able to do before?" You only need two coils ffs. Should I call universities to see my coils too?

EDIT2: And he claims "all energy is transmitted via ground"? Not true.. I should contact him.
 
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  • #50
Please do...I'm sure your input would be welcomed

The blog

[crackpot link deleted]
 
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  • #51
I'm amazed about the claim of 90% efficient transfer of power from one coil to another. What if another coil were put nearby? Would that get 90% of the power too? 180% of the input power would appear. That would be amazing good value.
 
  • #52
No. The input power would be shared between the two receivers. Tesla coils are "transponders" rather than transmitters and receivers.
 
  • #53
Meizirkki said:
No. The input power would be shared between the two receivers. Tesla coils are "transponders" rather than transmitters and receivers.

It's a transformer, in fact. Where's the magic in that? Not all transformers are made of iron and handle mains electricity.
I wish someone could tell me what's supposed to be different about these things with the name 'Tesla' attached to them. Transformer windings are essentially magnetically coupled coils because it is a near field effect and the impedance is not the same as for free space.
This way of close-coupling small pieces of equipment to a power source could have useful applications (subject to the interference levels being controlled). A 'charging table' would be another step up from 'the dock'. Efficiency need not be high because low power is involved.

But there seems to be some confusion about the distance over which this type of coupling exists. It is only in operation within a wavelength or so from the primary / transmitter. Only a 'free wave' will propagate over longer distances and energy can only be 'directed' using a large aperture antenna. Furthermore, the mutual impedance between wide spaced transmit and receive array is low (a receive antenna can't "suck" energy from the source). You cannot avoid 'wasting' most of your power and it is a brave man who disputes Maxwell's Equations.

People go and spoil it all by extrapolating a near-field process to long distance high power transmission as if it's the same thing. Tesla had a number of totally off the wall patents which are fully available for development but have never been (they were duff); there is no implication that a patented idea will actually work. Likewise, there may well have been uninformed pen-pushers in the Pentagon (or whatever it was called at the time) who decided that one or two of his untested ideas were a potential threat. There was no need to justify these decisions on rigorous technical grounds. Once declared secret, they were hidden from normal scrutiny and are not available for a healthy scrutiny /de-bunking. They just sit there, proving to the gullible that they are suppressed by that great conspiratorial body they love to hate. Tesla must be chuckling in his grave.
 
  • #54
Tesla coils joined in single base wire connection format connect by conduction. Tesla lodged his first patent application that said transmission and then set out another Patent with virtually the only difference being the word conduction. It appears that the engineers at the time didn't get the conduction thing. And he didnt mean by EM he meant by wire connection. A simple single wire system I have built demonstrates conduction through one wire not magnetic transfer of power since both coils are 180 degrees out of phase. If they were acting as a transformer or by electromagnetic connection they would need to be out of phase to transmit energy using magnetic energy. It uses voltage and Amperage to do the job. Sure, it puts out a little EM radiation but very limited and usesless in the process since it is out of phase.
 
  • #55
gushovard100 said:
Tesla coils joined in single base wire connection format connect by conduction. Tesla lodged his first patent application that said transmission and then set out another Patent with virtually the only difference being the word conduction. It appears that the engineers at the time didn't get the conduction thing. And he didnt mean by EM he meant by wire connection. A simple single wire system I have built demonstrates conduction through one wire not magnetic transfer of power since both coils are 180 degrees out of phase. If they were acting as a transformer or by electromagnetic connection they would need to be out of phase to transmit energy using magnetic energy. It uses voltage and Amperage to do the job. Sure, it puts out a little EM radiation but very limited and usesless in the process since it is out of phase.

Welcome
I suppose you acknowledge that Maxwell's Equations describe all there is to know about the way Electric and Magnetic Fields behave. In which case, if you attempt to give an 'explanation' of an electromagnetic phenomenon, it should follow from those equations.

Whatever the "conduction thing" is, Maxwell governs what happens. Maxwell applies to a simple battery and bulb circuit, a transformer, a coax cable, waveguide, near field - far field EM power transmission - everything. If you want to quote from a Patent as a form of proof of your ideas then that is not valid. There are millions of Patents based on absolute nonsense; we all know that.

Your simple "single conductor" system would need some more detailed description, along with measured results, to a reasonable standard.

"wire connection" involves EM just as much as a Radio transmitter. Read your EM theory. Not all EM waves are radiated waves.
 
  • #56
sophiecentaur said:
It's a transformer, in fact. Where's the magic in that?
...
I wish someone could tell me what's supposed to be different about these things with the name 'Tesla' attached to them.
Is there supposed to be magic in that? I'm really having some hard time here trying to understand your hate for Mr. Tesla. Yes Tesla coils are a sort of transformer and there is no magic.

I can (once again) try to explain you the major differences between Tesla coils and a conventional transformer:

- The secondaries can be far away from each other. Farther than magnetic induction used in conventional tranformers can reach.

- The secondaries do not need a conductor between them. The single wire used in my efficiency test can be replaced with a capacitor or a capacitance of natural medium such as water (I expect Earth grounding to work too, but I haven't tested it yet). I will provide test results for this later.

- Thanks to their structure, Tesla coils store energy in the oscillating field. This is rarely the case in conventional transformers.

- Conventional transformers tend to work with a wide range of frequencies, depending on their structure. Tesla coils work with only one frequency (though, input signal can be a harmonic of the oscillating field). The frequency of the oscillating fields is determined by the physical size and shape of the coil.

- Conventional transformers usually have many layers of wire on top of each other. Tesla coils can not operate if there is more than one layer. This is not a problem with isolation, but a necessity for the operation. The propagation of high frequency signal is very different in single and multilayer coils.

Hope this helps you understand the differences.
 
  • #57
I don't "hate" Mr T at all. What I do hate is the attitude that people have towards him. It is irrational and sycophantic. No one ever give me any solid evidence that his inventions are actually of any use (except the high voltage generator, which I have made and which is very impressive). The existence of Patents or 'suppressed secrets' are no evidence at all and neither are stories of American farmers experiences - with respect, they could have been persuaded that they had seen anything that Mr T told them they'd seen.

Transformers ("Understanding of"): I did not say that the Tesla design of transformer was conventional. The air core and the tuning are both significant differences between it and a mains transformer. Have you seen the transformer coupling that is used in radio IF strips or have you seen the transformer coupling that is used in Radio transmitters? No iron there, either and usually, a narrow band of operation. You mention specifics of coil design. If you look in radio engineering publications from the last century, you will find all sorts of wrinkles about how to wind the most effective and lossless coils for MF filtering and matching. It's very hard to characterise these structures (or at least it was, before computers were available).

As you haven't provided a drawing (schematic or otherwise) I can't comment on how this 'single wire coupling' operates. If you can't explain what is going on in terms of conventional EM theory then that doesn't mean anything special except that you haven't analysed what is going on. You are surely not trying to say that Maxwell doesn't apply to coils with a 'T' marked on their design.

'Storage of energy in an oscillating Field' is an example of Resonance. Inductive loop communication systems often to use resonance to improve efficiency.

You haven't said how you were measuring the Power in your experiment. It is extremely easy to confuse measured Voltage with Power and it is the bugbear of reliable RF power system appraisal. If those measurements are not bombproof then an apparent 90% could be a much lower real value. What did this efficiency test consist of? How did you ascertain the power that your source was delivering? What sort of separation have you made your system operate over?

a capacitance of natural medium such as water
This phrase rings alarm bells with me. I reads a bit 'new age' to be included in a serious discussion about an Engineering topic. What is it supposed to mean and how would it be implemented?
 
  • #58
sophiecentaur said:
This phrase rings alarm bells with me. I reads a bit 'new age' to be included in a serious discussion about an Engineering topic. What is it supposed to mean and how would it be implemented?

I did not mean the capacitance of water, sorry. I meant to say that it is possible to use capacitor in the place of wire, and natures own materials can be exploited to form this capacitor.

In his patents, Tesla has connected the sedondaries of his coils to Earth. I have not been able to test this yet, but I have (today) used water to form this capacitor. It is as simple as cutting the wire between secondaries and dropping the wires to a pot of water. They wire does not need to be stripped from insulating material. When both wires touch the water, it is enough to form the capacitor.

Air can not be used to form the capacitor explained above, because air is already used to form another capacitor at the top end of the coils. (Big spheres should be used at the top end, big surface area = more capacitance = longer distances)

Tesla called this "Disturbed ground and air method", which makes perfect sense to me.
 
  • #59
Meizirkki said:
I did not mean the capacitance of water, sorry. I meant to say that it is possible to use capacitor in the place of wire, and natures own materials can be exploited to form this capacitor.

In his patents, Tesla has connected the sedondaries of his coils to Earth. I have not been able to test this yet, but I have (today) used water to form this capacitor. It is as simple as cutting the wire between secondaries and dropping the wires to a pot of water. They wire does not need to be stripped from insulating material. When both wires touch the water, it is enough to form the capacitor.

Air can not be used to form the capacitor explained above, because air is already used to form another capacitor at the top end of the coils. (Big spheres should be used at the top end, big surface area = more capacitance = longer distances)

Tesla called this "Disturbed ground and air method", which makes perfect sense to me.
It would really help if you were to draw a diagram of what you see is going on here. The capacity between two spheres, separated by a few metres is extremely small ( a few tens of pF). The 'other ends' of the coils would be 'grounded' in some way, I imagine. With a stake in the ground or in a pool of water would make little difference. It's just an Earth connection between the two bases which would usually be best with a 'copper' plane between the two coils but a few wires would be almost as good.

There will be a mutual inductance between the two coils and a (tiny but finite) capacitance between them. That will be the coupling mechanism between the two in the near field. The far (radiated) field will not have established itself for a small separation but the currents in the two coils will be the result of the Impedance Matrix - self and mutual impedances and the 'drive point' voltage. Having resonant structures will give you effectively much bigger 'elements'. This is just an extension of the idea of top or bottom loading short monopole antennae.

btw, what sort of Q do you reckon you are finding for these coil / ball structures?
 
  • #60
sophiecentaur said:
It would really help if you were to draw a diagram of what you see is going on here. The capacity between two spheres, separated by a few metres is extremely small ( a few tens of pF).
...
btw, what sort of Q do you reckon you are finding for these coil / ball structures?
4YlVc.png

Here. This is how I think it works.

The capacitance is indeed very small. A friend of mine did some calculations and said it would be very unlikely for my coils achieve distances beyond ~100 meters. And this was for my first set of coils which operated at ~14MHz.

I can think of three ways to improve the distance: raising the voltage, installing a bigger sphere on top of the coils and using higher frequency.

I have not been able to test the Q of my coils in operation. I don't even know how to do it. If I remember correctly the LCR tester thingy showed a Q ratio of 5.5 for each of the secondary coils and 5 for the primaries. I am not sure about this though, and I don't know whether the tester is accurate.

Luckily my boss here in Germany is interested in this kind of "lost inventions" too. He provided me with materials and let me wind pancake coils for demonstration this week. I thought I wouldn't be able to do any testing this month, but thanks to him I've been able to test the "water capacitor" and try a bit longer distances. The function generator here can go only up to 1MHz which is just enough to achieve the transmission somewhat out of tune. I won't be measuring efficiency, but I can post here any tests that can be made without accurate measurements. (Demonstrating the water trick and longer distances).
 
  • #61
The distance between my two resonating tertiary coils is 1.5 meters and have a capacitance between them of about 2.5 pF. The coils operate under load with my current set up at about 9,000 volts. The way I measure power to the circuit is at the input to the primary coil which is at 24 volts. This is measured by an amps probe through an oscilloscope with peak current of 24 amps with a base of 6/10 us (only pulse one way) which gives about 10.18 amps RMS x 24 volts = circa 245 watts. This enables me to run 8 fluro lights in series with an RMS voltage drop across them of just on 1000 volts very brightly. A flame sometimes blows down the center of the lights and burns them out so I have to change them too regularly.

If we do the maths. I run the coils at 100,000 Hz. 2.5pF using 9,000 volts in each coil 180 deg out of phase falls a little short of the energy transfer between the coils to produce the above effect. My equipment is very reliable. Peak voltage drop phase to phase is 18,000 volts which means the maximum energy exchange between the coils is about 40 watts. This assumes the whole capacitive cavity has a voltage drop of 18,000 volts between the coils but it isnt. Top of one coil to bottom of the other is about 7,000 V so I have been really generous since reality is the actual transfer is probably way less than half this amount. The extra capacitance needed is normally termed stray capacitance. I need another 500% stray capacitance to get it to balance. The airbourne magnetic transfer is zero since the coils are 180 deg out of phase. I think Maxwell was one of the giants in this field. I even believe in the conservation of charge. I am starting to sound like I am at a religious convention LOL
 
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  • #62
  • #63
gushovard100 said:
I came across this series of videos which I like. This gentleman has heaps of coils all running synchronously.

http://www.youtube.com/user/moonfther

"A wireLESS system, using a single WIRE ?? Is that wireless or wired? The linking wire could be replaced by earthing each unit, I think. But at least he states that it's an induction system.
A very entertaining room full of stuff, driven off the same supply. I wonder what power it's using (and about the interference it's generating, too). No mention of efficiency.
 
  • #64
sophiecentaur said:
"A wireLESS system, using a single WIRE ?? Is that wireless or wired? The linking wire could be replaced by earthing each unit, I think. But at least he states that it's an induction system.
A very entertaining room full of stuff, driven off the same supply. I wonder what power it's using (and about the interference it's generating, too). No mention of efficiency.

It's in the comments of the second video.

This system runs off the grid...meaning I have my own power supply. Its a Solar set up charging a 12v 96 amp hr battery run through a 2000watt inverter giving me 110 out.
 
  • #66
You are making a very neat job of those constructions - well done. At least your results should be repeatable and reliable.

I have asked before but you still haven't mentioned how you actually measure the efficiency and powers involved.
You responded to my "2X90 = 180%" comment by saying that the power is divided between the two coils. Have you actually measured a drop of 50% in the power delivered to just one coil when another is introduced?
It would be interesting to know how those multiple coils in the 'garage full of Teslas' movie interacted with each other.

The 'concept' of EM coupling between structures is sound enough - it is definitely not "flawed" . The question is how much coupling is involved, which can only be determined through valid measurement.
 
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  • #67
Combsbt said:
It's in the comments of the second video.

I can hear no comments in any of the videos about the RF frequency used, the power involved (not the electricity supply power, which is not relevant) the Q of the coils of the Efficiency of the system. The only figure you quote is a 2kW inverter, which doesn't tell us any more than the maximum power it can supply.

Did you try operating the coils by sitting them all on a ground mat (mesh of wires) rather than a single wire?
 
  • #68
sophiecentaur said:
I have asked before but you still haven't mentioned how you actually measure the efficiency and powers involved.

Schematic and complete calculations are in the efficiency test paper, I hope they're presented clearly enough:

https://docs.google.com/document/d/1QirnU-yX7XPJY_1MaW0UqU-egkO3-6WoxhcDQ3yiOyE/edit

The schematic is a picture and those may take some time to load. If it fails to load on browser you can download the entire document as pdf and open it on your computer.
 
  • #69
Meizirkki said:
Schematic and complete calculations are in the efficiency test paper, I hope they're presented clearly enough:

https://docs.google.com/document/d/1QirnU-yX7XPJY_1MaW0UqU-egkO3-6WoxhcDQ3yiOyE/edit

The schematic is a picture and those may take some time to load. If it fails to load on browser you can download the entire document as pdf and open it on your computer.

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.
 
  • #70
sophiecentaur said:
Did you try operating the coils by sitting them all on a ground mat (mesh of wires) rather than a single wire?

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.
 
<h2>1. What is wireless power?</h2><p>Wireless power refers to the transmission of electrical energy from a power source to an electrical device without the use of physical wires or cables. This technology was first developed by Nikola Tesla in the late 19th century.</p><h2>2. How does wireless power work?</h2><p>Wireless power works through the use of electromagnetic induction. An alternating current is passed through a transmitter coil, creating a magnetic field. This magnetic field then induces a current in a receiver coil, which is connected to the device being powered.</p><h2>3. What are the benefits of wireless power?</h2><p>One of the main benefits of wireless power is convenience. It eliminates the need for cords and cables, making it easier to charge devices. It also reduces clutter and the risk of tripping over cords. Additionally, wireless power can be used for devices that are difficult to access or in hazardous environments.</p><h2>4. Are there any limitations to wireless power?</h2><p>One limitation of wireless power is its efficiency. Due to the distance between the transmitter and receiver coils, some energy is lost during transmission. This means that wireless power may not be as efficient as traditional wired power. Additionally, wireless power is currently limited to low-power devices such as smartphones and electric toothbrushes.</p><h2>5. Is wireless power safe?</h2><p>Yes, wireless power is generally considered safe. The technology operates at low power levels and does not pose a significant risk to human health. However, it is important to ensure that the power source and receiver are properly designed and maintained to prevent any potential hazards.</p>

1. What is wireless power?

Wireless power refers to the transmission of electrical energy from a power source to an electrical device without the use of physical wires or cables. This technology was first developed by Nikola Tesla in the late 19th century.

2. How does wireless power work?

Wireless power works through the use of electromagnetic induction. An alternating current is passed through a transmitter coil, creating a magnetic field. This magnetic field then induces a current in a receiver coil, which is connected to the device being powered.

3. What are the benefits of wireless power?

One of the main benefits of wireless power is convenience. It eliminates the need for cords and cables, making it easier to charge devices. It also reduces clutter and the risk of tripping over cords. Additionally, wireless power can be used for devices that are difficult to access or in hazardous environments.

4. Are there any limitations to wireless power?

One limitation of wireless power is its efficiency. Due to the distance between the transmitter and receiver coils, some energy is lost during transmission. This means that wireless power may not be as efficient as traditional wired power. Additionally, wireless power is currently limited to low-power devices such as smartphones and electric toothbrushes.

5. Is wireless power safe?

Yes, wireless power is generally considered safe. The technology operates at low power levels and does not pose a significant risk to human health. However, it is important to ensure that the power source and receiver are properly designed and maintained to prevent any potential hazards.

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