AC voltage from single magnetic pole

[nix85]

Abberation is half in + and half in -, thus it is perfectly usable.

But let's look at your marks. Indigo lines mark 90° from red lines.

56° would be just bit to the right from the middle.

Where are the yellow lines. 75-80°.

[verpies]

Question: Does the scope not represent at least a little bit of load on the coil, and wouldn't using a separate sensing coil similar to that used in the following video be a more accurate test? https://youtu.be/hw2bBYYHp34?t=89
Thank you.

No and Citfta's answer is correct.


This is because the impedance of the scope probe is so high that it is negligible at frequencies occurring in these mechanical machine Hz or kHz at most.
However if you were dealing with MHz frequencies or higher then the impedance of a typical scope probe would NOT be negligible anymore.  That's why in such scenarios active FET probes are preferred - they have an even higher impedance than passive scope probes.

...wouldn't using a separate sensing coil similar to that used in the following video be a more accurate test

Using separate coils for sensing the voltage and current is not more accurate and in my opinion it is not even necessary to resolve this issue, but it is cleaner conceptually and it is more difficult to object to the result of an experiment that uses separate coils for sensing induced voltage and induced current ...and since it does not skew the experiment much when identical coils are used, I just agree to it.

[verpies]

In the midtime, observe the phase shift without and with load in ordinary and bi transformer By Heins
youtube.com/watch?v=4_zgR5fyF30

Experiments involving transformers are not relevant to the issue at hand because transformers do not use single purely inductive circuits nor single RL circuits. They involve multiple RL circuits that are coupled magnetically.

The comparison of
the phase between the externally applied input voltage and the output current of a transformer,
is not the same as,
the phase between magnetically induced voltage and magnetically induced current in a single inductive circuit.

[partzman]

Nix,

Here is the source of the phase shift in the video you referenced.

A first test was made with a large coil for current sense with a flat voltage sense coil in parallel as in the test video.  This can be seen in the first pix.  A ceramic PM was passed in front of this assembly with the PM axis on axis with the coil assembly.  In the following scope pix we again see no phase shift.  CH1(yel) is the voltage and CH4(grn) is the current.

A second test was made with the same coils only now the current sensing coil was positioned at 90 degrees to the voltage sensing coil and the PM axis as seen in the third pix.  The PM was again hand passed in the same relative position as before and the 4th pix shows the resulting waveforms.  Here we see the source of the of the current lag in the video when one considers the positioning and timing of the PMs on the rotor to the coils.

This video therefore is no proof of your position IMO.

Regards,
Pm

[nix85]

Experiments involving transformers are not relevant to the issue at hand because transformers do not use single purely inductive circuits nor single RL circuits. They involve multiple RL circuits that are coupled magnetically.

The comparison of
the phase between the externally applied input voltage and the output current of a transformer,
is not the same as,
the phase between magnetically induced voltage and magnetically induced current in a single inductive circuit.

I did not post it as argument for anything, just as interesting video, curb your horses.