Critical pulse motor core info

[aether22]

All induction is counterproductive as all of it opposes change. (except in Thane and your designs)

If all induction was counterproductive, then Teslas AC "induction" motor would not have become a standard industrial tool worldwide. Without induction, no motor would run. Without induction you could put as much current through a wire coil as you liked, but it would not "induce" an aligned magnetic field into the metal core.

P.S There is no perfect system, so you will always have losses, be it from heat produced by eddy and load currents, or just plain old rotor windage and bearing friction. There will always be the possibility that better methods for reducing losses exist. Thats what R&D is for.

note: I have bolded the key stuff.

I meant induction of electric currents in magnetic cores and I stand by that fact that it is never useful unless Lenz Law on the whole is reversed and CoE no longer applies.
It is never intended or useful, induction motors have copper on the rotor in which current is induced.

Although I can successfully argue that while the induced current is not always counterproductive (in generators and transformers) the counter MMF it creates is NEVER useful even in induction motors since if it were somehow possible for the current to be produced without creating a magnetic field the rotor would still react but the stator would not know any induction had taken place and not be loaded.

I also was not talking about just anything that could be termed induction, the magnetic field induced by a current (not an induced current) is another subject again.

But misinterpretations of what I was saying aside I was not claiming that all losses can be removed (although correctly shaped metglass core with superconductive wire and magnetic bearing in vacuum also aside), what I was saying is that quite simply that the main thing reducing currents in a laminated steel core in an open magnetic circuit is likely the lower conductivity of steel since since the laminations do nothing to stop circling currents as they do in closed circuits although possible paths are limited it is still like having a shorted coil and expecting everything to be fine. (and even in Thanes and your setups it is still best for the electrical energy to be induced in the coil as it can be put to a use)

Nothing you have said as far as I can tell has discounted the fact that laminations provide no straightforward path for induced electrical currents to circulate in a closed magnetic systems (and only imperfections which can be very tiny given high operating efficiency from transformers cause any eddy currents not counting the incredibly tiny field created by circling currents within the thickness of the lamination which is ignorable and now I think about it likely what you were incorrectly referencing earlier).

Whereas the same laminated core in an open magnetic system is like a fat one turn shorted coil made of steel, where as eddy currents might have only caused a few % loss now in the closed path they might account for 50% or higher depending on how much current a pickup coil may be pulling, sharing half the energy with the core posing as a shorted coil sounds like bad practice to me.

[hoptoad]

All induction is counterproductive as all of it opposes change. (except in Thane and your designs)

If all induction was counterproductive, then Teslas AC "induction" motor would not have become a standard industrial tool worldwide. Without induction, no motor would run. Without induction you could put as much current through a wire coil as you liked, but it would not "induce" an aligned magnetic field into the metal core.

P.S There is no perfect system, so you will always have losses, be it from heat produced by eddy and load currents, or just plain old rotor windage and bearing friction. There will always be the possibility that better methods for reducing losses exist. Thats what R&D is for.

note: I have bolded the key stuff.

I meant induction of electric currents in magnetic cores and I stand by that fact that it is never useful unless Lenz Law on the whole is reversed and CoE no longer applies.
It is never intended or useful, induction motors have copper on the rotor in which current is induced.

Although I can successfully argue that while the induced current is not always counterproductive (in generators and transformers) the counter MMF it creates is NEVER useful even in induction motors since if it were somehow possible for the current to be produced without creating a magnetic field the rotor would still react but the stator would not know any induction had taken place and not be loaded.

I also was not talking about just anything that could be termed induction, the magnetic field induced by a current (not an induced current) is another subject again.

But misinterpretations of what I was saying aside I was not claiming that all losses can be removed (although correctly shaped metglass core with superconductive wire and magnetic bearing in vacuum also aside), what I was saying is that quite simply that the main thing reducing currents in a laminated steel core in an open magnetic circuit is likely the lower conductivity of steel since since the laminations do nothing to stop circling currents as they do in closed circuits although possible paths are limited it is still like having a shorted coil and expecting everything to be fine. (and even in Thanes and your setups it is still best for the electrical energy to be induced in the coil as it can be put to a use)

Nothing you have said as far as I can tell has discounted the fact that laminations provide no straightforward path for induced electrical currents to circulate in a closed magnetic systems (and only imperfections which can be very tiny given high operating efficiency from transformers cause any eddy currents not counting the incredibly tiny field created by circling currents within the thickness of the lamination which is ignorable and now I think about it likely what you were incorrectly referencing earlier).

Whereas the same laminated core in an open magnetic system is like a fat one turn shorted coil made of steel, where as eddy currents might have only caused a few % loss now in the closed path they might account for 50% or higher depending on how much current a pickup coil may be pulling, sharing half the energy with the core posing as a shorted coil sounds like bad practice to me.

@ No arguments here, I'm not trying to convince you that laminations work well or even work at all, I merely put forward the accepted theory.
I have no particular argument with accepted theory on this matter. Whilst I have used laminates in various experiments, I found solenoid cores to be superior for use in my own particular experiments.

With regard to all you have stated above, you may well be right. 

But, if your explanations for the behaviour of open magnetic systems ares based purely on theoretical postulations without knowledge derived from hands on experimentation and the resulting data, then you may be falling into the trap of believing assumptions about things which may be proscribed as true in theory but not evident in reality. 

Something to ponder. If a non linear reaction occurs in a system that is meant by the laws of that system to be linear, then can you trust the accepted laws of that system ?. In other words, if the outcome is not in line with the modeled prediction, then which is incorrect, the outcome or the prediction? Setting up virtual models and thought experiments is not the same as setting up real experiments and gaining real data. Test your theory in practice.

I look forward to the results.

Cheers

[aether22]

Be that as it may I have no doubt at all that I'm right about this.

It is not worth my time to verify and complication in testing comes from differing permeabilities due to the different ways of dividing the core so that would need to be accounted for.

Though the easiest test would be to make a coil that assumes the shape of a lamination and verify it gets a voltage induced to the expected extent.

Note: Another way to look at it is like this, look at illustration 1, imagine that the coil pictured is producing a north pole up.
Now see that before the flux gets to the other end mach will leave from the sides.
And if we now replace the lamination with a coil of the same shape (or cut the center of the lamination out and now call it a one turn shorted coil) we see that as the flux stength varies so does the level of flux threading our shorted coil and unless the laws of induction are on a break a voltage will be induced, and the critical part will not face cancellation from and other currents.
But in a closed path all the flux leaves through the 2 ends and none of it leaves out the side to induce our laminate coil.



BY THE WAY, THIS THREAD IS A REPRODUCTION OF THE ONE IN NEWS TITLED:
THIS IS HUGE, MUST READ!! All methods to reduce eddy currents useless! -*

IT MAKES SENSE TO HAVE A NOTE OF THIS DISCOVERY IN THE PULSE MOTOR SECTION BUT IT IS A BAD IDEA TO KEEP 2 SIMILAR ACTIVE THREADS SO STOP REPLYING TO THIS ONE AND HEAD OVER THERE.

HOPEFULLY THIS CAN BE MADE STICKY TO STAY AT THE TOP OF THE PULSE MOTOR FORUM

SO PLEASE DO NOT REPLY IN HERE, THANKS

[Mr.Entropy]

And there are 20 of them!

Each dissipating 1/400th the energy or so, because P=V^2/R, and each producing 1/400th the flux (1/20th area * 1/20th current).