Tesla's "COIL FOR ELECTRO-MAGNETS".

[gyulasun]

@Gyula:
Excellent testing and demonstrations. You are doing a lot to clear up the misconceptions held by certain people about what a "Tesla bifilar" coil is and how it works.
There is one other type of "bifilar" coil that is often used and confused with Tesla's design. This is the "hairpin" coil. The hairpin configuration uses the same amount of wire but is non-inductive. If you have the time, you might consider winding a third bolt as a hairpin, and repeat the inductance and electromagnet tests with it.
The hairpin winding is just what you did for the Tesla bifilar, but without cutting and splicing the ends.
....

Hi TinselKoala,

I repeated the "paperclip" tests with nuts and with the two coils separated, you may have seen it here:
http://www.overunity.com/11350/confirming-the-delayed-lenz-effect/msg357952/#msg357952

What you suggested above as testing the so called 'hairpin' coil I have done it too by now, albeit I wondered what sense it may have if we all know that such coil you referred to above obviously has no inductance or only a very very little.
Nevertheless, I cut the same 6 meter long piece of enameled+silk insulated wire, OD= 0.3mm (awg #29), I folded the wire into half and wound onto a third identical bolt like the ones used for the other two coils.  I started the winding with the folded end of the wire, did not cut it, and guided the two parallel wires close to each other as I progressed with it.  Finally I cleaned the two open ends of the wire and connected them to my power supply. DC current I used now was abouit 420mA as earlier and there was not even a single small nut lifted by this electromagnet. 
Measuring this coil with an L meter, it showed a fluctuating value between zero and 1uH. When I short circuit the L meter input with a thick piece of short wire it measures zero, unfortunately the most sensitive range it has is 2mH, so this coil must have a less then 1uH inductance.

In the meantime, I freshed up my info on Tesla 'hairpin' experiments because for me it has meant a different setup.  Everybody can read it here, only two pages long, including  Figures 19a,  b and c.  See Pages 36 and 37 in this PDF file:
http://www.free-energy.ws/pdf/1893onlight.pdf 
And the hairpin shape is created in Fig.19c when the upper ends of the parallel lines B and B1 are shorted with copper bar B2 and the upper 50V lamp remains dark while the lower 100V lamp (not far from the 50V lamp) is bright.

Nowadays such tests are called standing wave tests I think where current and voltage nodes are created on (transmission or here Lecher) lines and the voltage and current levels are changing as per the length of the line and the AC frequency determine it, together with the termination of the line, be it an open or a shorted end or a matched load end (for this latter matched load case there would be no standing waves).  Info on Lecher line: http://en.wikipedia.org/wiki/Lecher_lines

rgds, Gyula

[Magluvin]

I did the nail coil tests and with just a D batt each picked up the same amount of material.
I thought about it a bit more, as we should, and the nail would probably create eddy losses if the field wanted to build quickly. Just thoughts. Also the battery voltage is pretty low, considering Tesla said that more turns, more voltage, more effect.

So I wound a new coil, actually 2. One is made from 14 strands of fine relay coil wire. Once it was wound, I separated the strands(all marked previous to winding) to have 4 leads of 7 strands each. It is wound on a small bobbin for an E core that mostly encases the bobbin. It should have decent capacitance upgrade and inductance inside the core compared to the nails.

Then I made a larger air core coil wound with 26awg x 2 for about 900 turns total. The nails were within spec at 23awg.

The larger coil will be tested as an inductor and a motor drive and/or gen coil.

Got an Arduino board with a touch screen display that will be programmed to run things. Naudin has some vids out with the Arduino controlling a pulse motor and Its very cool. Im going to expand on that model with a menu based testing module. Will post it as I go. Got the display pretty much figured out in programming. Also got an SD card shield for logging and expansion.

Mags

[gyulasun]

Hi Mags,

Thanks for doing and reporting the tests, this confirms my findings with the bolt tests ( http://www.overunity.com/11350/confirming-the-delayed-lenz-effect/msg357838/#msg357838 and here is a repeated test: http://www.overunity.com/11350/confirming-the-delayed-lenz-effect/msg357952/#msg357952 
Regarding the transient switch-on moment you mention as eddy current loss possibility in the nails, this is possible of course but remember it must happen in both the normally and the bifilarly wound nails so the eddy loss effect in this case is irrevelant when comparing their performance.
You mention the low battery voltage and that Tesla said the more turns, more voltage, more effect:  I think the main message Tesla patent Coil for Electromagnets includes is that choosing parallel guided wires and connecting them in series (aiding phase) there is a (resonant LC) frequency where the coil will have no inductive opposition to a certain AC input current flow due to the resonant effect the increased (and distributed) coil capacitance makes with the coil inductance.
This resonant state cannot be input voltage dependent, it is just a coincidence, Tesla did many tests with high voltages indeed and I think his example in the patent involved 1000V for explanation purposes. He even mentioned in the patent that high voltage capacitors were difficult to make (at the time) so increasing the (distributed) capacitance between the wires by suitable insulation material was a means to solve the HV capacitor issue.  I also believe that Tesla did not mean his pancake coils for electromagnet usages only, he has several patents on either single wire or wireless energy transfer where he also showed the pancake coil configurations and the coil resonance had to be involved there for sure, using his series bifilar pancake coils.
Of course it is difficult and mainly restricted by coil construction to build such bifilarly wound coils to fit your various switching frequency necessities for the many tasks  i.e. especially for the lower some hundred Hz or less frequencies. You have to know how to increase the capacitance between the wires (for instance using wires with rectangular cross section instead of the normal circular, or use Alu or copper foil windings with thin insulating layer between them, that would increase the facing 'capacitor' areas) and still there can be limits.

Looking forward to your findings with those beautiful coils you have shown above.

Thanks,  Gyula

[Magluvin]

Hi Mags,

Thanks for doing and reporting the tests, this confirms my findings with the bolt tests (

No problem.  I had to do it. I had to put it to the test with thoughts of what if. If I dont, I may walk away and miss out.  I generally wont delve into a large venture replication unless its my idea or if other replicators have flown, but not many of them around.

I just need to put this bifi coil thing to sleep or wake it up.     Ive seen some interesting devices that claimed to use bifi coils and in the end, it was never really resolved as to if they really worked or not.

I have some self conflicts with what might the coil be used for and what style of coil would be best for its use if there are any. I dont see them out there anywhere being used much. Why is that? Waste of time? Well I cannot walk away from a 250,000 times increase what ever it is, as long as its not resistance.  Maybe that number can be more, or even less depending. I really have not seen 250,000 anything with someone using low voltage, and have not seen much high voltage used except in fewer turns so maybe that needs to be the focus. Start with low voltage and go upward, using a many turn coil of course.

What exactly does 250,000 in this sense mean? Lets say that we have a coil of many turns and the resistance of the coil is 1000ohm with 10v applied to it. It will eventually reach .01 amp once the field has peaked. The max consumption would be 0.1w. Now figure in the number 250,000 with those numbers, any which way we can. It still adds up to a whole lot, whether it is a spike or what ever, that is not something to ignore. Is it?

Maybe Tesla 'is' only talking about an AC current. Does that make the number 250k any smaller in meaning?

I think we need to put that big number on the table until we understand what it means really.

I dont know if Tesla intended to use it in pancake/planar coils or not. If he did, more than likely it would have related to what freq he wanted to work with. Like a primary for a Tesla coil, Ive seen bifi, thick insulated wire, pancake made of few turns. Like less than 10. So there wouldnt be much capacitance and not much coil. So very high freq is the intention.

But if there is advantage to more and more turns, then a thousand turns of pancake is a lot. If there is a purpose, I dont know. So im going for the rolled coils to get more turns, as T said it can be applied to any style of coil. I think the diagrams of pancake coils in the Pat makes for simple understanding of what is intended on how to make it..

I cant say that the expression of 1000 turns in the pat is just meant for ease of understanding. That doesnt go along with more turns more effect, and clearly the nails dont seem to express any difference. But that may be a bad example to start off with. lol my larger coil shown above mysteriously only about 9 times as many turns, but there is a LOT more capacitance increase because the outer turns of the coil have more length per turn. So cant calculate capacitance as only a 9 times increase. Will check all these. Im interested to see the capacitance of the multi strand coil compared to the large coil. Will do this tonight.


As far as the nail coils, would there be a difference between the 2 if they were run at a freq the bifi nail rings at? maybe nothing. Havnt seen it tried, much less you and I actually doing the initial test. 

I wonder why someone would put that up and know that it doesnt work? And show it in its minimalist way. If Tesla did have anything, and some of his writings show it in an inconspicuous way, would there be interest in deflecting the train of thought of those ambitious enough to really study his works? If we are going to continue our endeavors, then this is one device that needs to be understood. Put to sleep or woken up. 

Mags

[Magluvin]

Testing the large coil above, capacitance is 16.8nf - .016uf. Not to shabby. DVMs with cap measure capability must be affected drastically when measuring across an inductor or coil from end to end, conductive ends of the same winding. The coil I pulled half of the bifi from is a single strand of maybe 4000 to 5000 turns. Its still about 4 to 5 times heavier since the bifi wind.

When measuring the capacitance of the big big coil, from end to end I got .1mf - 100uf  This is the single strand doner coil.

When I measured the bifi, 1 continuous strand from end to end I got 3.6mf - 3600uf Its a much smaller coil than big big. And im just measuring 1 strand from end to end. Wonder what the capacitance reading would be if the 1 strand were wound by itself. I know this is not the 'tool' for measuring an inductor.

It must be how the reading or determining of the capacitance in the meter that way misinterprets this reading, because Im not measuring a cap but an inductor.

Yep, just checked some things. Shorting the meter leads shows in mf 000 like its beyond its reading. Tried some other coils and the ones with the most turns of fine wire show lower than thick wire of fewer turns as the fewer thicker are closer to acting like meter leads shorted.  Anyways. lol

When I read the bifi strand for capacitance across the wire, not between the 2 wires I get 3.6mf (thats milli farad, just in case some think Im confusing uf in this post ), 1 strand of 2 from end to end. Then I just put the 2 in bifi series and measured again from end to far end end. Got 3.6mf again.    Considering I get different results using the cap meter to measure different coils, as long as they are not too stout to overload, why do I get the same readings from 1 strand in this coil whether its just measuring 1 strand or both in series? Something is odd there. Who woulda thunk. Mags thunk it. lol

I just did this test as I posted this. I double checked and still the same weirdness. Dont have an Inductance meter. Gota git one. Im programing the arduino to do things like that but it would be good to have a meter handy.

Ok, broke away to try something. My meter has a tone function that relates to the readings. It functions in cap mode. I hear a chirp every half a second or so. So this must be what is happening with the inductors. The cap meter is sending charge and measuring the time to charge. So the cap meter just may be able to read a range of coils and probably fairly accurate if a chart is made out to relate the capacitance reading to the inductance of the coil. Interesting. For this meter anyways. Wavetek 2030 Oldie but a goodie.

Mags