Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding

User Menu

Custom Search

Author Topic: Sharing ideas on how to make a more efficent motor using Flyback (MODERATED)  (Read 349990 times)

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
I am basing my comments on what I actually see when a pulsing coil does a motor action and makes something move by exporting power to the outside world.   Are you "sure" those are the conditions that Poynt was talking about?  Perhaps he was referencing more of a static condition where the magnet does not move?  Perhaps it also depends on the relative directions of the magnet's field lines and the coil's field lines since magnetic fields are a vector quantity with magnitude and direction?

You need to think more than one or two steps deep for all this stuff.

Magluvin referenced a book where a a coil with a ferrite core can be "preloaded" under the influence of an external magnetic field.  Considering in my example the two magnetic fields are 180 degrees diametrically opposed I think that will apply in this case.  It looks like when the coil first energizes it has to do the work to "clear out" the biasing of the core which is in the opposite direction that the coil wants to fire.  That sounds to me like it will increase the effective inductance - in this case.

On the other hand, if a static and unmoving magnet was "behind" the coil and biasing the core in the "right" direction, then when the coil was energized then in short order the core would get saturated and go "air core."  That sounds like it would reduce the effective inductance to me.  See?  You actually have to think these things through.

If we want to be more complete in our description it looks like there are several effects:

1) The coil when energized has to "clear out" the biasing of the core and then start biasing the core the "right" way.
2.1) When the magnet moves away, an EMF will be induced in the coil that is opposite that of the battery.
2.2) It's likely that the summation (integration) of the  "negative EMF" times the instantaneous current flow represents the energy that is put into the moving mass of the magnet - the motor action.
3) Points 1) and 2) above will work to slow the increasing of the current flow when the coil is energized, which effectively makes it look like the coil is a higher inductance - and reduce the average power consumption of the coil.
4) The distributed resistance of the wire of the coil is always there in the background dissipating energy and working to slow down the current flow.

You note that the simple test that pushes a magnet away gives you a more controlled environment to see the effects of the EMF from the magnet moving away from the coil.   In a real pulse motor you actually have the magnet approaching and then leaving the coil, the associated acceleration and deceleration of the rotor, and the interaction with the timing of the firing of the pulse.

That's about all that I can think of and I intentionally ignored discussing the back spike.  I have never done any of this stuff in real life.  I am forced to try to visualize it in my mind.

You can investigate what is taking place to any level of detail that you want.  What you can't do is cherry pick one thing and then blindly assume that it applies to all cases without thinking things through.  That seems to happen way too often around here.

MileHigh

tinman

  • Hero Member
  • *****
  • Posts: 5365




MileHigh

Quote
I am basing my comments on what I actually see when a pulsing coil does a motor action and makes something move by exporting power to the outside world.   Are you "sure" those are the conditions that Poynt was talking about?  Perhaps he was referencing more of a static condition where the magnet does not move?  Perhaps it also depends on the relative directions of the magnet's field lines and the coil's field lines since magnetic fields are a vector quantity with magnitude and direction?

Well as we have all be discussing magnets moving in relation to stationary core's,then one would hope that he was talking about the same thing,if he was trying to explain as to what is happening.\

Quote
You need to think more than one or two steps deep for all this stuff.

It would appear as though i have thought deeper about this than what you and Poynt have.
I will talk about this some more toward the end of my reply to your post.

Quote
Magluvin referenced a book where a a coil with a ferrite core can be "preloaded" under the influence of an external magnetic field.  Considering in my example the two magnetic fields are 180 degrees diametrically opposed I think that will apply in this case.  It looks like when the coil first energizes it has to do the work to "clear out" the biasing of the core which is in the opposite direction that the coil wants to fire.  That sounds to me like it will increase the effective inductance - in this case.

Lol-amazing . Here i have been,trying to tell you this on two thread's !!for how long now!!?,and all i get from you and Poynt ,is that is incorrect.

Quote
On the other hand, if a static and unmoving magnet was "behind" the coil and biasing the core in the "right" direction, then when the coil was energized then in short order the core would get saturated and go "air core."  That sounds like it would reduce the effective inductance to me.  See?  You actually have to think these things through.

!!We!! have to thinks things through ::)-->man,where have you been for the last two week's-->and what have myself and Luc been trying to tell you??.
We have to think things through Lol--is this some sort of joke MH?.

If we want to be more complete in our description it looks like there are several effects:



Quote
1) The coil when energized has to "clear out" the biasing of the core and then start biasing the core the "right" way.

As i have been trying to tell you and Poynt for weeks now.

Quote
2.1) When the magnet moves away, an EMF will be induced in the coil that is opposite that of the battery.

Not with my DUT,as it is the south field that is approaching the core of the coil that produces a north field at the end of the coil where the rotor is. But this has nothing to do with the reduction in current on the P/in side.--Detailed reason and evidence at bottom of this post--that you seem'd to have overlooked.

Quote
2.2) It's likely that the summation (integration) of the  "negative EMF" times the instantaneous current flow represents the energy that is put into the moving mass of the magnet - the motor action.

So once again we are being told that energy from the coil is transferred to the rotor,and at the same time the rotor returns this stored energy,!!BUT!! the I/ in drop's resulting in less P/in. Once again-some how,we have put energy into the rotor,and taken that energy back out(equal and opposite-minus losses due to windage and bearing friction of the rotor),but seem to have reduced the P/in ::).

Quote
3) Points 1) and 2) above will work to slow the increasing of the current flow when the coil is energized, which effectively makes it look like the coil is a higher inductance - and reduce the average power consumption of the coil.

Thats because the coils inductance has risen.

Quote
4) The distributed resistance of the wire of the coil is always there in the background dissipating energy and working to slow down the current flow.

Really?-->we shall see.

Quote
That's about all that I can think of and I intentionally ignored discussing the back spike.  I have never done any of this stuff in real life.  I am forced to try to visualize it in my mind.

And that is where you fail. The vital information to understanding what is happening,is right there in the back spike.  And you say we need to look further than just two step's,while you have totally ignored the very thing that is showing you that the induced reverse voltage across the coil from the moving magnet is not what is reducing the I/in-P/in. This !is! the case with Poynt's sim(that was suppose to simulate the results of my DUT,but did not),but not the case with my DUT.

Quote
You can investigate what is taking place to any level of detail that you want.What you can't do is cherry pick one thing and then blindly assume that it applies to all cases without thinking things through.    That seems to happen way too often around here.

I really cannot believe what i am reading in this whole post of your MH--it is truly unbelievable  :o
Quote: What you can't do is cherry pick one thing and then blindly assume that it applies to all cases without thinking things through.

And this is exactly what you have done throughout the ages you have been here on this forum. You blindly stick to what the books tell you,and everything must obey the !known! laws-->which are based only around current observations-->thats right MH-observations,and observations are not laws. With people like you trying to sway others that see different,is it any wonder that any new observations have never been see.

You tell us that !we! need to look at more than two thing;s,and yet here you admit to leaving out the one thing that provides all the answers--the inductive kickback current.

You insist that we cant just cherry pick one thing ,and blindly assume that it applies to all cases--and yet here you are saying,or trying to preach that everything must abide by these know laws--everything.

You clearly have the inability to stand back,and have an unbiased  go at working this out. You must stick to your known laws that are based only on observations so far. You preach books that are filled with information that is 100's of years old-->and we are suppose to be looking for the energy of the future.

Poynts quick little attempt at trying to replicate my DUT's test results failed. What he showed was !your! normal outcome,from your known !!laws!!. He succeeded in reducing the I/in-P/in,and as a result,he also reduced the P/out. Why did his results show this?. That is easy-the inductance of the coil remained the same when he switched on his tank circuit,that was suppose to represent a magnet moving toward and away from the core of the coil. As the inductance remained the same,then when the current was reduced,then so was the magnitude of the magnetic field built up around the coil/inductor. We know this is true,because the I/out-P/out also dropped<--this is the bit you chose to ignore,and your undoing to understanding that what i have been saying is true,and in the case of my DUT,it has nothing to do with the induced reverse voltage across the coil.

Look closely at the scope shots below MH-->do you see a reduction in the I/out P/out in my DUT/
No,in fact you see an increase,and this increase was measured by both the scope across the CVR,and also by the DMM's across the CVR-->both methods recommended by both you and Poynt.
So now all you have to do,is work out as to why or how we can have a reduction of current flowing into the coil,and yet have an increase of current flowing out of the coil--how is it that my results are opposite to that of what Poynt showed?. How can you decrease the current flowing into an inductor,and yet increase the current flowing out of the inductor during the kickback.

The only way to increase the current flowing out of the inductor(when the inductors wire and turn ratio remain the same),is to increase the magnitude of the magnetic field that is built up around the inductor. Now,how can that magnetic field be increased if we have just decreased the I/in-P/in of that inductor MH?. Well the answer is simple--the inductance of that inductor had to have increased. You wrote this your self MH--Quote: It looks like when the coil first energizes it has to do the work to "clear out" the biasing of the core which is in the opposite direction that the coil wants to fire. And this is exactly what happens with my DUT,and is exactly what i have been saying,and trying to tell you on two different thread for the past 3 weeks.
Again-->As the south field of the magnet on my rotor approaches the core of the coil,it induces that field into the core. When the coil fires,it fires a !!north!! field at the end of the coil that is closest to the rotor.  You just said exactly what i have been saying for over three week's,and during that time,you !and Poynt! are trying to tell us all here that it is this !!cannot be seen!! reverse voltage across the coil that is the reason for the reduction in current draw during the ON time. Well in Poynt's Sym case,that is correct,as the I/out also went down<-- Your lenz's law.
But in my case,we have a situation where the I/in went down,but the I/out went up. If what you and Poynt are saying were true with my DUT,then we would have seen the same results Poynt showed,in that when the I/in was reduced,then the I/out would have also been reduced--but it was not-it increased.

So i hope you take some notice of your own words,and go and have a closer look at what is happening with my DUT. Try and be unbiased for once in your life MH.

Re-posted on my thread.


Brad

verpies

  • Hero Member
  • *****
  • Posts: 3473
Okay, here is a generic test done by me demonstrating an increase of Inductance when approaching a magnet to a coil wound on a Finmet toroid core.
If you pulse a coil on a Finemet toroid and approaches a magnet the result will be a decease of current just as JLN  and myself have demonstrated.
Link to my demo done back in 2011: https://www.youtube.com/watch?v=_cCYKChCFqk
That is a very interesting phenomenon that does not occur very often.

When the PM aligns the domains in the same direction as the coil's current, then the apparent inductance decreases.
However, when the PM aligns the domains in the opposite direction as the coil's current, then the apparent inductance increases.

In other words, the inductance is measured relative to the equilibrium level of the domains.
The equilibrium level is the level of domain polarization to which the domains return spontaneously, when the current in the coil falls back to zero.

When the PM polarizes the domains one direction and the coil's current - in the opposite direction, then more headroom is created to accept the energy delivered by the coil before saturation occurs.
Without the PM, the coil can polarize the domains only from 0 to some maximum positive domain polarization.
With the PM, the coil can polarize the domains from some negative domain polarization to the maximum positive domain polarization - that increases the headroom a lot.

While analyzing such problems, it is useful to be mindful of the distinction between the "differential permeability" and the "absolute permeability" of the core and the entire magnetic circuit.
Actually it is about the non-linearity of the BH curve and the directional opposition of polarization vector components, but let's not split hairs.

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Verpies:

I don't disagree with you but I believe that the explanation is somewhat different in this case.  Apparently for a Finemet-type nanocrystaline magnetic material in tape form, a magnetic field passing normal to the tape can increase the energy storage properties of the material.  I did a search and found the attached document.

If you look at Luc's clip, the geometry between the magnet placement and the Finement tape toroid does the trick.  I got beat up for my ignorance, I hope that doesn't happen to you.

MileHigh

verpies

  • Hero Member
  • *****
  • Posts: 3473
Apparently for a Finemet-type nanocrystaline magnetic material in tape form, a magnetic field passing normal to the tape can increase the energy storage properties of the material.  I did a search and found the attached document.
So Finemet is transversely anisotropic.  That exacerbates the directional domain polarization effects.
Thanks for the paper.

poynt99

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 3582
That is a very interesting phenomenon that does not occur very often.

When the PM aligns the domains in the same direction as the coil's current, then the apparent inductance decreases.
However, when the PM aligns the domains in the opposite direction as the coil's current, then the apparent inductance increases.

In other words, the inductance is measured relative to the equilibrium level of the domains.
The equilibrium level is the level of domain polarization to which the domains return spontaneously, when the current in the coil falls back to zero.

When the PM polarizes the domains one direction and the coil's current - in the opposite direction, then more headroom is created to accept the energy delivered by the coil before saturation occurs.
Without the PM, the coil can polarize the domains only from 0 to some maximum positive domain polarization.
With the PM, the coil can polarize the domains from some negative domain polarization to the maximum positive domain polarization - that increases the headroom a lot.

While analyzing such problems, it is useful to be mindful of the distinction between the "differential permeability" and the "absolute permeability" of the core and the entire magnetic circuit.
Actually it is about the non-linearity of the BH curve and the directional opposition of polarization vector components, but let's not split hairs.

Sounds like you read my post.
http://overunity.com/16261/rotating-magnetic-fields-and-inductors/msg470331/#msg470331

verpies

  • Hero Member
  • *****
  • Posts: 3473
Sounds like you read my post.
http://overunity.com/16261/rotating-magnetic-fields-and-inductors/msg470331/#msg470331
No, I didn't but evidently you were first with this line of thinking.

Magluvin also:
So when we pulse a coil on the rod core with dc, we are only able to use half of the magnetization curve of the core. But when we bias the core with a magnet, with biasing in the opposite polarity of what the coil produces when pulsed, we now have access to the full magnetization curve of the core. By doing so we get almost twice as much ampere turns capability from the same coil/core with magnet bias vs without the magnet.
And it also increases inductance..  Its in the book. ;) ;D

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Note in essence it's a zero sum game.   If you reverse the current flow through the coil, the inductance is decreased.

gotoluc

  • elite_member
  • Hero Member
  • ******
  • Posts: 3096
That is a very interesting phenomenon that does not occur very often.

When the PM aligns the domains in the same direction as the coil's current, then the apparent inductance decreases.
However, when the PM aligns the domains in the opposite direction as the coil's current, then the apparent inductance increases.

I'm glad you find it interesting and so did I when I saw it back in 2011.
Now, is there a way we can use this in our favor before they remove consumer access to Finmet cores?

BTW, I have your circuit on a project board ready to test.
Do I need any caps on the MIC4451YN mosfet drivers chip?
Will the 5vdc input be enough for the MIC4451YN mosfet drivers to switch the mosfet's on?

Thanks for your help

Luc

poynt99

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 3582
Let's have some fun and put this to bed. You up for a challenge Brad?

I challenge you to an efficiency battle using only flyback from a coil. You stick with your iron core coil and rotor of magnets, and I'll use whatever coil I choose, but with no rotor, and no resonant tank. What do you say?

Let me know if you're up for it, then we can agree on some goals for the challenge.  ;D

gotoluc

  • elite_member
  • Hero Member
  • ******
  • Posts: 3096
Let's have some fun and put this to bed. You up for a challenge Brad?

I challenge you to an efficiency battle using only flyback from a coil. You stick with your iron core coil and rotor of magnets, and I'll use whatever coil I choose, but with no rotor, and no resonant tank. What do you say?

Let me know if you're up for it, then we can agree on some goals for the challenge.  ;D

oh, oh, oh, can I play too?

verpies

  • Hero Member
  • *****
  • Posts: 3473
BTW, I have your circuit on a project board ready to test.
Looks well.
It seems that you run out of the yellow jumpers.

I have to ask Grumage to make me a machine to strip and bend those jumpers with an adjustable length.

Now, is there a way we can use this in our favor before they remove consumer access to Finmet cores?
I would have to think about it how they would behave in the classical Magnetic Amplifier application and go from there.

Do I need any caps on the MIC4451YN mosfet drivers chip?
As usual, it is a good practice to have additional ~0.1μF power supply decoupling caps between power supply pins (pins 7 & 14) of these 4047 chips and the power supply pins of MOSFET drivers, but I almost never draw these decoupling caps on schematics unless their absence is known to cause problems.

Will the 5vdc input be enough for the MIC4451YN MOSFET drivers to switch the MOSFETs on?
Only with the so called "logic level" MOSFETs and I don't think yours are one of those.
If I were you, I'd go for the standard 12VDC power supply to drive the MOSFETs hard and give the MIC4451YN drivers separate power supply lines (see the Starpoint below) so they don't spike-up the 4047 chips.
Take example from Itsu - he must be doing something right if his waveforms are so clean...

poynt99

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 3582

tinman

  • Hero Member
  • *****
  • Posts: 5365
No, I didn't but evidently you were first with this line of thinking.

Magluvin also:

Really?

Myself and Luc have been saying this for weeks,and Poynt finally thinks there may be a way that the inductance of the coil can be increased by way of a PM's field,and he is the first in this line of thinking???.

I have shown my DUT,and how it is set up right from the start of my thread. I posted a quick test carried out showing where the south magnetic field of the rotor magnet was in relation to the coil which created a north field at the rotor end when switched on. Is it not clear that the core of the coil would have that south magnetic field induced into it before the current started flowing through the coil,and that the field in the core would flip from south to north when the transistor was switched on.

For weeks now we have been trying to tell you this is why the P/in is reduced,and the P/out can remain the same,and for the same amount of time MH and Poynt have been saying it is because of some fantasy revers voltage that you cant see is the reason for the effect. Only now dose Poynt work out how this might be the case,and he is the first with this line of thinking?--!!really!!.


So often we see the little guys discovering effects like this,and the so called big guns taking credit for it.

Well Luc showed it in 2011,so you EE guys are only 4 years behind.


Brad.

tinman

  • Hero Member
  • *****
  • Posts: 5365
Let's have some fun and put this to bed. You up for a challenge Brad?

I challenge you to an efficiency battle using only flyback from a coil. You stick with your iron core coil and rotor of magnets, and I'll use whatever coil I choose, but with no rotor, and no resonant tank. What do you say?

Let me know if you're up for it, then we can agree on some goals for the challenge.  ;D

My reply to Poynt from my thread.


Sure-you know me-I never back down from a challenge.

But first you must finish the challenge you have already voluntarily half completed--> and that is to get your simulated setup to replicate my results from my DUT. That is-to get the output current-power to increase when the input current-power is decreased.
Once you have answered and completed that challenge you put upon your self, then we can set the ! Apples for Apples! parameters for the next challenge.

You will of course be required to build an actual device for the next challenge-as I do. And you will be required to post a video here on this thread of your device under test, and the results obtained from that test during the video--> as I do.

So yes, im up for the challenge as long as we are on equal ground.