AC voltage from single magnetic pole

[nix85]

Not really, it is just a badly designed experiment, namely two disparate measurements of the filament in two very different physical conditions.
If the resistance measurement of a hot filament is made then the Ohm's Law holds.

Wow, you must be a genius. Totally blew my mind.

It was just an example how law can be perceived as violated when it really was not.

As usual, you missed the point.

OK, but as you have just illustrated, a badly designed experiment will yield bad results, so we will have to design a good experiment to which we both agree.By turning on a very small (mW) heater, you can locally heat the superconducting loop so it becomes resistive. Now you can apply a voltage to the circuit - and it will preferentially send current around the superconducting part of the loop. The current will not be infinite though - for a given inductance L, the magnet will "ramp" as the current increases according to
V=−LdIdt

What i referred to was not an experiment.

I could use a NbTi coil but the dewar will obscure its view and the LH is is expensive and will break the clamp-on current probe for oscilloscope.

That is doable with two identical low-resistance coils and two identical magnets, but the coil for measuring induced voltage should not be in close proximity to the shorted coil used for measuring current because the latter may distort the permanent magnet's flux which reaches inside the former coil.

IMO it is important, that the two coils and magnets are identical to prevent any differences in their behavior. This should be verifiable by swapping their roles at any time.
Also, I think that when both coils are opened and used for induced voltage measurement, then both voltage waveforms generated by them, should be identical and appear in-phase on the scope. Two out-of-phase induced voltage waveforms would indicate misalignment and would necessitate calibration of the apparatus.

Do you think that a result of such experiment would constitute an objective proof or disproof of the 1 BTC challange ?

I just linked to a video of perfect 90° phase shift in closed aircore coil.

You claim coil without resistance would have 0 phase shift.

I leave it to you to prove your claim in objective, scientific manner.

This guy put it nicely...

"In a superconductor, the current can keep flowing "forever" since there is no resistance. But since conductors have inductance (in fact, superconductors are used most often to create magnets like for an MRI scanner), applying a voltage would not (immediately) cause an infinite current to flow.

By turning on a very small (mW) heater, you can locally heat the superconducting loop so it becomes resistive. Now you can apply a voltage to the circuit - and it will preferentially send current around the superconducting part of the loop. The current will not be infinite though - for a given inductance L, the magnet will "ramp" as the current increases according to V=−LdI/dt"

https://physics.stackexchange.com/questions/179374/is-current-in-superconductors-infinite-if-they-have-0-resistance-then-i-v-r-s

[verpies]

Video link:
https://vimeo.com/466592675

Thank you for doing that experiment, but I am afraid that it will not put this dispute to bed.


This is because this experiment was designed according to your ideas and not nix85's.  The rules of science say that both parties must agree to the experimental conditions.


1) We both don't like ferromagnetic cores in the coils, because ferromagnetism is a very complex secondary phenomenon and we are trying to avoid such confounding factors.


2) Nix85 wants to use 2 coils. One for measuring current and one for measuring voltage. While I don't think two coils are necessary to prove/disprove the issue at hand, I want to accommodate him ...and since two identical coils will not skew the experiment,  I agree to them.


3) I think the voltage signals form the two open coils should be identical and in-phase for the purpose of the calibration of the apparatus and the coils cannot be in close proximity ...and in your apparatus this means two identical coils placed diametrically opposite around the flywheel and two identical magnets (with identical poles sticking out) placed diametrically opposite on the flywheel.

[partzman]

You mixed the turns, voltage coil should have little turns, not vice versa.

Also you moved magnet by hand altho inductive reactance is undetectable at such low frequency.

It's funny how you try to prove he's right with resistive coils while doing the test wrongly forgetting he is making a claim for PURELY INDUCTIVE COIL.

Nix,

This test has L1 and L2 reversed.  IOW, L1 is now the current sense winding and L2 is the voltage sense winding.  The inductance of L1 is 143uH and the DCR is .38 ohms.  L1 is wound with 100 turns as stated before and is wound with 15-34 litz wire as is L2.

As one can see, the voltage and current are still in-phase.

How pure an inductive coil do you desire?  How about giving a desired L/R ratio?  IOW, at what point do we begin to see a phase shift towards 90 degrees current lag?

I am not favoring anyone here, I am interested in the science.

Regards,
Pm

[nix85]

Nix,

This test has L1 and L2 reversed.  IOW, L1 is now the current sense winding and L2 is the voltage sense winding.  The inductance of L1 is 143uH and the DCR is .38 ohms.  L1 is wound with 100 turns as stated before and is wound with 15-34 litz wire as is L2.

As one can see, the voltage and current are still in-phase.

How pure an inductive coil do you desire?  How about giving a desired L/R ratio?  IOW, at what point do we begin to see a phase shift towards 90 degrees current lag?

I am not favoring anyone here, I am interested in the science.

Regards,
Pm

Look at the vid i linked.

Makes you wonder if phase shift is 90° when he barely pushed it with hand, how much would it be at 1000 or 2000 rpm.

[partzman]

Look at the vid i linked.

Makes you wonder if phase shift is 90° when he barely pushed it with hand, how much would it be at 1000 or 2000 rpm.

Nix,

Are you sure you and the author of this video have interpreted the results correctly?  Here we see three coils spaced the same distance apart as the PMs in the rotor.  However, the first two coils relative to the rotational direction of the rotor, have their axis at 90 degrees to the PM axis while the third coil with the voltage sense coil have their axis in line with the PM axis.  Aren't we apples to oranges here?  The current phase in the first two coils at 90 degrees off-axis will be different that the third on-axis coil. 

Also notice the screenshot taken below that is early in the test, shows the current waveform more symmetrical around zero as compared to the shot you choose to use in the later part of the video.  In the screen shot below, the phase is not even close to 90 degrees but appears from dimensional measurement to be more like 56 degrees. 

In the scope pix you show taken at the later time in the video, the current waveform has shifted considerably upwards off center and does appear to be closer to 90 degrees.

Also, you criticized my frequency using the hand passed PM but this test has a half period of ~15ms where with my test the same half period is ~17ms!?

IMO, this video does nothing to confirm your position.

Regards,
Pm