Rotating Magnetic Field's and Inductors.

[sm0ky2]

what you are touching on is a unique field of study.
Not many people choose to go down that road, thus the mathematics are sometimes more difficult to find.
What you are seeing here is governed by Solenoid Mechanics.

to see the true effects on an "energy based analysis", you will need a much smaller capacitor.
That large cap holds well beyond the energy required to create the maximum force between
that coil - magnet pair. The mass or weight of the magnet plays a very tiny role.
It's mostly about the physical dimensions of the magnet compared to its' strength.

If you have a smaller capacitor, one that can just barely throw the smaller magnet to the max (15cm?)
Then you can use that as a baseline energy for your tests.

The stronger magnet is capable of a much larger force when opposed by another field as a factor Teslas (or Gauss)

[tinman]

Hence my "not practical at this time" and "thought experiment" comments.  However, the results would be similar.





I am not arguing against the increase in efficiency by using PM's, just the idea that heat is somehow being converted by the PM's.  You can choose to produce the same HP out for less input or more HP out for the same input.  But again, there is no mechanism converting heat into something.,   
There you go with the "useful work" phrase again...  Do you mean to say non-conservative or perhaps just work?

In any event, measurements accepted, the spinning rotor test had a 40% or so efficiency without the rotor, and something better with it.  What was seen was a decrease of the system's inefficiency (or increase of efficiency if you prefer).

Other modifications could also improve the efficiency, possibly more so than the PM's, but the constraints you placed on your definition of "useful work" does not allow those improvements to be considered useful work.

   

PW

If your core is ferromagnetic, very likely attraction will overcome the repulsion produced by the eddy currents.  Try spinning your rotor near a sheet of copper and see what the induced eddy currents do for you.  I believe the eddy current thing is a non-starter and only produces losses.

Thats a totally different situation PW,and not really related to what we are talking about here. The sheet of copper for 1,is non magnetic(magnets are not attracted to it),and 2,it is nothing more than a shorted turn.

I believe my analogy was just fine as it was.  If the road is the "motor housing" as you put it, is not the stator firmly attached to that housing?

As well, if I am a swimmer pushing off against the wall of a pool, is the pool wall doing work to accelerate me?

If we have equal and opposite forces,then yes,the pool wall is pushing against you as much as you are pushing against the pool wall. What happens if we move the frame of reference from the pool wall to you--what is now moving when you are the reference point when you push against the pool wall?.

I understand what you are saying, but again, although you are "eliminating" a source of heat, no heat is being "converted".

And yet in my test with the spinning rotor,when we stopped that rotor.the P/in went up,and the P/out went down. So the external alternating magnetic field was converting something while spinning past the coil,as we changed nothing else in the system. Regardless of what it was,a conversion was taking place because of the magnets.

If I swap out my incandescent bulbs for LED's, are my LED's converting heat into something?  I say no.  Depending on whether I choose to increase or decrease the input, I can achieve the same light output for less input, or more light output for the same input.  The use of LED's has increased the input/output efficiency but nowhere in the LED is heat being converted into something else (ignoring the heat generated by the LED of course).

Why do you say no,when it is obvious that by replacing one with the other,you have indeed reduced waste heat,reduce P/in,and obtained the same light output. Your LED is doing useful work-is it not?.

If the core of your inductor was replaced with ferrite to eliminate all eddy currents in the core, would that not qualify as "useful work" per your definition?  All losses by that particular mechanism would be eliminated, not just reduced...

Here is something interesting to think about.
I have been building pulse motors for many years now,and have tried many things to increase the efficiency of pulse motors. A side by side comparison shows that using a ferrite core in a pulse motor is less efficient that using a laminated steel or soft iron core-as far as electrical P/in ,and electrical,mechanical P/out go's. Ferrite cores seem only to become more efficient when used in high frequency pulsed systems--without rotating external magnetic fields.

Looking at your answer regarding the stator windings doing useful work,and my point about frame of reference. If we hold the shaft of the motor still,and let the motor housing spin instead(like an out runner motor),are the stator coils doing useful work now?,and if the rotor is no longer spinning,dose that mean that it is no longer doing useful work?. So if motion is what you think needs to be the decider on what part of the device is doing the useful work,then what happens when we swap out the stotor coils that are now spinning in stead of the rotor,and we replace them with the PM's. So now the PM's are spinning,and the rotor has no motion--are the PM's doing the work now?.   You can see now why your reference to the pools wall,and the road to that of the wheels dose not fit in here.


Brad

[MileHigh]

what you are touching on is a unique field of study.
Not many people choose to go down that road, thus the mathematics are sometimes more difficult to find.
What you are seeing here is governed by Solenoid Mechanics.

to see the true effects on an "energy based analysis", you will need a much smaller capacitor.
That large cap holds well beyond the energy required to create the maximum force between
that coil - magnet pair. The mass or weight of the magnet plays a very tiny role.
It's mostly about the physical dimensions of the magnet compared to its' strength.

If you have a smaller capacitor, one that can just barely throw the smaller magnet to the max (15cm?)
Then you can use that as a baseline energy for your tests.

The stronger magnet is capable of a much larger force when opposed by another field as a factor Teslas (or Gauss)

You don't really need to have a smaller capacitor.  Anybody with a DSO, a large capacitor, a MOSFET switch and a one-shot 555 timer circuit, a current sensing resistor, a diode, and a collecting cap for the back spike should be able to make a simple conclusive test showing exactly what's happening and do a complete energy analysis.

[MileHigh]

Brad:

The fundamental problem issue is that you are trying to define "useful work" as the "the conversion of heat power into mechanical power" when that never actually happens.  The only two examples that I am aware of for that, excluding the thermal component that is seen in conventional power generation, are for a carnot engine and for a thermoelectric generator.  In both examples we are talking about a single device, a single case examined on its own merits.

You, on the other hand, are comparing two separate and different and distinct cases, and making a claim that magnets are producing "useful work."  In both cases, it's the input electrical energy that ultimately does the useful work and the magnets contribute zero.  Many examples of two separate cases have been given to you that do exactly the same thing, poor bearings vs. good bearings, resistive wire vs. lower resistance wire, and you reject them and want to single out magnets as doing something special and in fact the magnets are no different from the other examples.  That's the fundamental issue.

It all goes back to a fundamental problem that you see around here all the time:  I change a parameter in my setup and see reduced input power and claim victory when all that you really have done is change the overall impedance of the system resulting in a change in the power drawn by the system.  Reducing the power draw by increasing the overall impedance but still measuring the same output does not mean "free energy" - all that it means is that you have reduced the production of waste heat.

Hacking a universal motor by adding magnets will simply reduce the production of waste heat - nothing more.  In the unmodified universal motor, and in the modified motor, if you could make precise measurements of the waste heat power in both cases and factor it out, then you would find that in both cases the electrical power in is greater than or equal to the mechanical power out.  The magnets will have changed nothing and do not contribute any "useful work" or hypothetical "magnetic power."

In other words, a magnet is not a magic bottomless cup of coffee that spouts a fountain of watts fed by the Clockwork of Nature that in theory can produce an infinite amount of energy.  A magnet is as dead as a doornail and produces nothing at all.  It's just pushed around by the input electrical power like a rag doll.  It can sometimes change the impedance of a setup and result in less waste heat power being produced, which is not really different than swapping out a rusty bearing for a new bearing.

Forget about a universal motor - there is no way that you can do a simple controlled experiment that demonstrates a magnet producing energy.  Just like there is no way that anybody can do a simple controlled experiment that demonstrates a coil producing energy.  But the reality is that there are many people on this forum that do believe that magnets and coils produce energy - hence you have the cottage industry of criminals trying to scam people.

MileHigh

[picowatt]

Thats a totally different situation PW,and not really related to what we are talking about here. The sheet of copper for 1,is non magnetic(magnets are not attracted to it),and 2,it is nothing more than a shorted turn.

No, its not a "different situation".  Perhaps you are confusing eddy currents with something else. 

https://www.youtube.com/watch?v=Yu1uRvErM80   

(there is/was a better video demonstrating this, perhaps someone can post a link)

If we have equal and opposite forces,then yes,the pool wall is pushing against you as much as you are pushing against the pool wall. What happens if we move the frame of reference from the pool wall to you--what is now moving when you are the reference point when you push against the pool wall?.

I sad I was having a conundrum over the stator question.

I also considered the rotor being rotating PM's as in a BLDC motor.  Indeed where is the "work" actually being performed.  From which perspective (frame of reference) or element do we consider the question?  My original analogy of the accelerating vehicle is a good one to ponder.  I wish others would chime in on this.

And yet in my test with the spinning rotor,when we stopped that rotor.the P/in went up,and the P/out went down. So the external alternating magnetic field was converting something while spinning past the coil,as we changed nothing else in the system. Regardless of what it was,a conversion was taking place because of the magnets.

We can speculate why it is that what is observed is taking place, but any further understanding will require additional experiments.

There is plenty of waste going around in your test device as demonstrated by its 40% efficiency when operated as a boost converter without the rotor.  As I mentioned earlier, perhaps the rotor is capturing a portion of that 60% that is being wasted and returning it to the system during the off period. 

I believe a high resolution measurement/observation of the rotor's acceleration, deceleration. and timing would shed additional light on what is happening.

Why do you say no,when it is obvious that by replacing one with the other,you have indeed reduced waste heat,reduce P/in,and obtained the same light output. Your LED is doing useful work-is it not?.

Because I see no apparatus or mechanism acting in some manner as a heat engine doing a "conversion" of heat into something else. 

As you say, waste heat has been reduced or eliminated, which increases efficiency, but that is not being done by installing a mechanism that converts heat.

Here is something interesting to think about.
I have been building pulse motors for many years now,and have tried many things to increase the efficiency of pulse motors. A side by side comparison shows that using a ferrite core in a pulse motor is less efficient that using a laminated steel or soft iron core-as far as electrical P/in ,and electrical,mechanical P/out go's. Ferrite cores seem only to become more efficient when used in high frequency pulsed systems--without rotating external magnetic fields.

Be that as it may, it was a thought experiment regarding your "useful work" definition.  it would have been nice if you would have answered the question, in further clarification of your term "useful work", instead of going off on ferrites.

Looking at your answer regarding the stator windings doing useful work,and my point about frame of reference. If we hold the shaft of the motor still,and let the motor housing spin instead(like an out runner motor),are the stator coils doing useful work now?,and if the rotor is no longer spinning,dose that mean that it is no longer doing useful work?. So if motion is what you think needs to be the decider on what part of the device is doing the useful work,then what happens when we swap out the stotor coils that are now spinning in stead of the rotor,and we replace them with the PM's. So now the PM's are spinning,and the rotor has no motion--are the PM's doing the work now?.   You can see now why your reference to the pools wall,and the road to that of the wheels dose not fit in here.

I think both of my analogies work here, but I prefer my original accelerating auto analogy.  Just as you describe above, one can speculate the possibility that if the auto is held stationary, the road itself must accelerate (consider a toy car and a globe of the Earth if necessary). 

To me, the question as to whether the stator actually does work is not all that clear cut.

I wish others would comment on this...

PW