Confirming the Delayed Lenz Effect

[Magluvin]

Lorentz force acting on moving charges resulting in moire patterns:

http://www.youtube.com/watch?v=h89TaH6Er1Y

Very cool, but is this the only way we can visualize this? If we do the same with iron filings under glass, would it show these differences? Or even the standard view of a magnet where the iron filings show the N and S fields to the left and the right? Would the S(right) side show a more expanded field than the N(left)?

Orrr, is it possible that the yokes in the monitor causing the difference in what we are seeing between the N poles down and the S poles down? Or some other factors within the monitor itself like maybe the anode screen being charged upwards of 30kv, because as we know, magnetics and electrics are interactive. Think about this. If the yoke fields  in the monitor can alter the electron beam up, down, left and right, might not there be a possibility that the high voltage electron beams could have an affect on the tuning forks magnets fields, depending on their polarities??

Im not quite buying that as an example of an egg shaped field between N and S.

It was a cool vid to say the 'most', but does it have a point when it comes to this thread?

Mags

[ALVARO_CS]

MileHigh: for the moment it holds it very well, I guess the 3055 is very robust, or the kick back gets dissipated via diode and coil A,
I have used this setup many times and never failed.  I recently got a hall switch to use it with mosfets and will need another kind of driving circuit, but I will stand with this kind of coils, as it has proven to deliver a stronger thrust.
Thanks for your remark

[synchro1]

Retrod is spinning a tube magnet with a 70 hertz a.c. signal from a sine wave audio generator. The magnet's in "Synch" with the signal, higher then the spin rate. The SBC resonating signal is pure sine a.c. also. Perhaps it drives my high speed precision ceramic bearing reed switch magnet motor the same way, with an a.c. frequency harmonic from the SBC L-C  resonance?

http://www.youtube.com/watch?v=pQ7Ax_b6S4k

The oscillation takes over and leaves the reed switch behind. The amplified tank resonance powers the magnet spinner alone, with no further measurable input from the power source. The SBC resonant signal may be in the megahertz range!

[gyulasun]

Hi synchro1,

I thought to make two electromagnets like the link (you referred to http://www.tesla-coil-builder.com/bifilar_electromagnet.htm ) shows. I used two identical sized bolts M6x40mm (i.e OD 6mm length 40mm).  I used two 6 meter long enamelled+silk insulated copper wires, OD 0.3mm (awg #29).

I wound one 6m wire as a single wire onto one of the bolts, lets name it bolt1, it has about 136 turns, DC resistance is 1.6 Ohm, inductance is 416 uH. 
I folded into half the other 6m long wire and wound the two parallel wires onto the other bolt, let's name it bolt2, it has about 63 bifilar turns, then I identified the wire ends of the coils on bolt2 and connected the end of the first wire to the start of the second wire. Thus the two wires in series have DC resistance also 1.6 Ohm, inductance in series is 423 uH, individually each coil is about 107uH.
When these two latter coil wires are unconnected from the series aiding fashion, the capacitance between either the two wire ends or between the wire starts is measured as about 220 pF with a C meter.
Obviously, the tiny difference between the inductances on the two bolts (416 uH and 423 uH) can be explained by any difference in the permeabilities of the bolt materials.

Then I connected the coils on bolt1 and bolt2 in series and switched onto a mini variable DC power supply (see picture) to have the same current flow in both of them at the same time and started to lift paper clips with them. I noticed soon that the clips do not readily attract to each other when being the third or the fourth in a vertical line, the last one or two easily fall down. So I chained first 3 - 3 clips as if they were members of a chain and then the electromagnets could lift them up without falling for even a small unintentional movement.
It turned out soon that the bifilarly wound coil performs the same as the single wire coil. Finally I chained 4 - 4 clips and at a given
current (about 0.42 Amper at 1.5V) each electromagnet was able to hold its four member chain as shown in the picture, any more clips chained into either the single wire or the bifilar wire electromagnet fell down, there was no holding force for more clips in any of the electromagnets at the 0.42 Amper DC current level.

For me this test shows that when a bifilar coil is wound with N/2 number of turns with respect to a comparable single wire coil with N number of turns and the two windings within the bifilar coil are connected in series (in aiding phase, not in cancelling phase) to get the same N number of turns, then there is no any advantage to make a bifilar coil WHEN you use it as a DC operated electromagnet. 
I am not saying that such bifilar coil, when operated with AC or pulsed DC current, performs the same way as the comparable single wire coil, it can have the advantage like Tesla found (when driven with AC or pulsed DC current at the bifilar coi's resonant frequency,  i.e. you apply the patent correctly).
I am saying that out of these two electromagnets, made as per described in the link, the bifilarly wound electromagnet has no advantage in lifting force at a steady DC current.

The lifting force of a bifilarly wound electromagnet can surely double for DC current too IF you make N number of turns bifilarly and compare its holding force to a single wire coil wound also with N number of turns, in this case the advantage is clear because when you connect the bifilarly wound windings in series you will have a resulting coil with actually 2N number of turns versus the single wire wound coil with N number of turns.

HOWEVER, for the bifilarly wound coil in this example you have to use thicker wire to make the bifilar N number of turns because when you connect the two windings in series, it should have the same DC resistance like the single wire coil has, wound with also N number of turns, to make the two performance comparable correctly.

And remember, the website did not claim that the bifilarly wound electromagnet on the nail lifted up twice as many clips as the single wire electromagnet did. (No such claim on that site, you claimed it in Post #998, page 67 in this thread).

I hope this helps. I have no intention to argue with you,  I wrote what I found in the test and explained my findings.

PS  regarding the strong electromagnets used in scrapyards you mention, the 'trick' is to use pot-magnet-like electromagnets where BOTH poles of the electromagnet are arranged to appear on the same (facing) side and their flux can close THROUGH the ferromagnetic target to be lifted. See pot magnets or a laudspeaker designs. The pot magnet design 'trick' can multiply the holding force at least 7 to 10 times when compared to the holding force of the same coil and DC input power but it uses one of its poles only for lifting.

rgds, Gyula

[Farmhand]

Very informative test Gyulasun, that is the test we needed to see done and get the results from, thank you very much for doing that.

Ampere turns rules the day. Makes complete sense.

Now could you possibly test the resonant frequency of both of those coils ?

And see if there is a difference in resonant frequency in the bifilarly wound coil when excited by 1 volt as compared to 10 volts ?

My Function generator is analogue and the frequency drifts a lot, it's almost useless. I'm going to buy another digital one. I get more stable signals with a circuit I made
but it's a pain to adjust and has limited range.

Cheers