Study of Generator Coil Acceleration Under Load (moderated)

[gotoluc]

Okay, we can stop this now, it's gone far enough.
MH is mostly right. I must admit the reality of AUL effect is not as good as it looked in my video demo, which I purposely did to demonstrate what many are seeing in their tests and as a learning tool for those who play around with this stuff.
I know better not to use a solid steel rod, a bolt, welding rods, or even for that matter transformer laminations. Unless you want to show or demonstrate this effect just to waste power
Core Hysteresis is exactly what causes AUL and it comes at a cost to the prime mover.

When you use quality cores like Metglas, 90% or more of AUL goes away. So MH is right about that.
However, the phase shift you saw in the video by sliding the coil further away on the core still remains and I would suggest this is what needs to be further tested (obviously with the right cores) to see if this has any advantages.

I will post a new video demonstrating the reality of AUL when using Metglas core compared to a solid steel core.
Some of you will be surprised of how drastic the change is.

I'm sorry if this has caused some people grief or trouble. My intention is to bring awareness on the subject which has been highly debated over the years.

Stay tuned for the comparison test

Luc

[plengo]

However, the phase shift you saw in the video by sliding the coil further away on the core still remains and I would suggest this is what needs to be further tested (obviously with the right cores) to see if this has any advantages.

Thanks for the note gotluc. I see MH point and your emphasis on the phase shift which is very significant since this is the area between apparent power and real power manifestation (usage). Removing load (MH argument) is logical but does not explain indeed the phase shift which seams to be the main variable here.


Fausto.

[MileHigh]

Luc:

If you claim core hysteresis is the main cause of "AUL" and if you one day choose to pursue this further then you have back up that claim with solid data.  Right now I am not smelling that at all, and it would probably not be trivial to measure core hysteresis losses and it would only be one part of the load on the prime mover.

My feeling is that the electrical load due to the coil + resistor in any before/after configuration analysis is the main agent that is causing a mechanical load on the prime mover, and hysteresis losses would be secondary.  It's just a feeling with no measurements to back it up.

It's hard to say where the phase shift is coming from exactly because I don't know exactly how to model the setup.  The model might be as simple as a coil (stray inductance) and a resistor (pickup coil driving resistive load) in series.  Without being sure, it would at least appear there is a decent chance that the stray inductance leaking out of the core when the movable coil is far away is the main cause of the phase shift.  I seriously doubt the phase shift is having a large impact on the final RPM but one more time you never know.  Like I said before, the best way to approach that would be to do a timing diagram analysis where you plot the estimated back-torque on the prime mover during a full revolution.

The real moral of the story for the people that this was being presented to is to make proper measurements and do your best to properly interpret your measurements and analyze them.  Full schematics, measurements, interpretation and analysis, and then trying to draw the proper conclusions.  That's the way for experimenters to properly share data and work together in a synergistic manner.  However, a good first start would be to simply measure the electrical power dissipated on the coil + load resistor for the "before" and "after" configurations.  If the power dissipation data is leaping out at you as an explanation for the "effect" then that should be sufficient.  People can still work on measuring the core losses if they want to see where that leads them.

It may all sound like a big pain in the ass but this is real electronics.  Taking shortcuts is too dangerous and can lead to improper conclusions.

MileHigh

[wattsup]

@gotoluc

OK but listen,

you already did the experiment right and at around 13 min you showed the cogging. So the cogging proves you found a good slide position on the core no matter the material, cogging is a good sign. So what is the cogging saying to you? Maybe it's saying "Hey man, I want to give you some good amps and all you want with that fat single coil is volts."

Now how could you increase amps instead of volts? Maximum output has always been a dance between volts and amps. Is it possible that you can output more watts when working to output more amps? Or a mix of both that come together parallel. These are not bad questions to answer again regardless of the core if you are getting cogging on the drive motor that becomes a base.

wattsup

[gotoluc]

Okay everyone, I made the video as promised but like TinMan says, better make some popcorn cause it's a long one. Actually the longest video I have ever made!... 45 minutes of boring measurements

Hope this helps bring a better understanding on this effect.

Link to the movie: https://www.youtube.com/watch?v=NYGM4UlnqTM

Enjoy

Luc