Author Topic: Sharing ideas on how to make a more efficent motor using Flyback (MODERATED) (Read 357362 times)

gotoluc · « **Reply #825 on:** March 27, 2016, 03:24:28 AM »

Hi Didier, what if we consider magnetization time and and make the rotor and stator segment very long.

In most electric motors the rotor and stator segments are at most 30 degrees or less in length. So if you build it that way I don't see an advantage. But what if the segments were 90 degrees long, since once the magnetization has occurred there is no extra cost to attract a very long rotor segment, no?

If you wish I can give you some measurements on how much weigh the magnetization can lift including a standard motor air gap.

Let me know

Luc

Khwartz · « **Reply #826 on:** March 27, 2016, 09:59:31 PM »

Quote from: gotoluc on March 27, 2016, 03:24:28 AM

Hi Didier, what if we consider magnetization time and and make the rotor and stator segment very long.

In most electric motors the rotor and stator segments are at most 30 degrees or less in length. So if you build it that way I don't see an advantage. But what if the segments were 90 degrees long, since once the magnetization has occurred there is no extra cost to attract a very long rotor segment, no?

Hi Luc, as said elsewhere, I am not skill enough in this area to answer you with any certainty.

But what about just two rotating barres (for the balance) with 4 reluctant switched coils magnets as stator at 90°, that you can change with ordinary electromagnets, wouldn't be easier to test?

Quote

If you wish I can give you some measurements on how much weigh the magnetization can lift including a standard motor air gap.

Let me know

Luc

In my humble opinion, it would be the minimum do to in any case.

Thanks for your Interest, Luc, for your experiments,

Regards,
Didier

gotoluc · « **Reply #827 on:** March 27, 2016, 11:17:12 PM »

Yes Didier, your test suggestion is good and I may do something like that if it is needed.
However, as you may know Robert Murray-Smith is presently looking into the matter and I'll wait till he posts his new video demo with his calculations.

Thanks for your interest

Luc

shylo · « **Reply #828 on:** March 29, 2016, 01:07:09 AM »

Hi Luc, I did a test where I put 4 I strips on my big neo (2 on each side) to match the length of a secondary coil from a MOT (on it's edge),and placed ceramic's between the I's in the hole of the secondary. Then I put another I across the ends of the 2 on each side. It still has 2 poles ,but when the coil is pulsed , it makes the poles change.
The way you have it , it's either magnetic or it's not?
A very weak field but it is there.
artv

MagnaProp · « **Reply #829 on:** March 29, 2016, 01:17:00 AM »

Quote from: shylo on March 29, 2016, 01:07:09 AM

... It still has 2 poles ,but when the coil is pulsed , it makes the poles change.
The way you have it , it's either magnetic or it's not?
...

Can you draw a simple image of what you have done? I can't tell from the written description. Thanks in advance for any help. I'm looking for the switching of poles as you describe. The best I can come up with so far is basically two of gotoluc's devices but that would be twice as heavy with only half of the magnets being used at any given time. Would also take more power to switch two Alnico's.

truesearch · « **Reply #830 on:** March 29, 2016, 04:09:45 PM »

@shylo:

I too would like to see a drawing or picture of how you

Quote

It still has 2 poles ,but when the coil is pulsed , it makes the poles change.

truesearch

shylo · « **Reply #831 on:** March 30, 2016, 10:26:37 AM »

Here's a different one seems to work better.(see attached)
I'm going to try and see if I can maybe use it to assist rotation of my rotor.
I was just powering it with some of the stored flyback.
artv

MagnaProp · « **Reply #832 on:** March 30, 2016, 12:13:58 PM »

Quote from: shylo on March 30, 2016, 10:26:37 AM

Here's a different one seems to work better...

Thanks for the image.
You're using all Alnico magnets and no Neo's? So you switch the poles by switching all magnets?

gotoluc · « **Reply #833 on:** March 30, 2016, 04:05:05 PM »

Quote from: MagnaProp on March 30, 2016, 12:13:58 PM

You're using all Alnico magnets and no Neo's? So you switch the poles by switching all magnets?

No, he wrote he is using all ceramic magnets.

Luc

shylo · « **Reply #834 on:** March 30, 2016, 09:47:09 PM »

The poles at the end of the I's are opposite each other, N & S, when pulsed they switch polarity.
The big ring is a neo,
The little fillers in the center of the coil are ceramic's.
It makes for a weak field but the closer the better.
artv

MagnaProp · « **Reply #835 on:** March 30, 2016, 10:58:50 PM »

Quote from: shylo on March 30, 2016, 09:47:09 PM

...It makes for a weak field but the closer the better...

Still not sure how it works. When you switch the ceramic magnets, instead of closing the loop with the neo, the ceramic magnets over power the round neo to the point that more ceramic field exits the I instead of the neo field?

If I still have it wrong, then I'll leave it at that and thank you for posting the info. @gotluc- Thanks for the clarification.

shylo · « **Reply #836 on:** March 31, 2016, 10:38:27 AM »

There is no way the little chunks of ceramic (cut up speaker magnets) could over power that neo ,it is very strong.
I put one I-core on one side of the neo, lay the coil on, place the ceramics in the hole of the coil , then put the other I on.
The ends of the I's each have their own pole a N & S, power the coil and the poles flip at the ends of the I's.
Without powering the coil , if you bring a magnet of the same pole close to the I, you can feel the repulsion , power the coil and the magnet gets sucked in.
Pretty simple to test, I'm gonna try it without even using the ceramics' , maybe even placing more I's all around.
Hope that's clear enough.
artv

gotoluc · « **Reply #837 on:** March 31, 2016, 05:17:14 PM »

The ideal way to get the strongest flux out of this design would be to use only neo magnets. However, to re-magnetize (flip the pole) of a neo magnet would require a very large amount of power. So there would be no point to even try this.
Alnico magnets are a step down from neo's. So if you compare an equal size alnico to a neo, the alnico would be about half the strength of the neo. So this is part of what makes the alnico easier to re-magnetize compared to the neo.
Now if you compare equal size ceramic to a alnico, the ceramic would be about half the strength of the alnico.

So syhlo, I hope you understand that this is the reason you're not having much success with your test device, as you are using magnets of two different extremes. Not only that but the neo looks to be larger in size then the ceramic magnets.
You may want to consider using all ceramics and keep the size ratio the same. Or try 2 to 3 times the size (mass) of ceramic to size ratio of neo.

Luc

verpies · « **Reply #838 on:** April 02, 2016, 10:41:29 AM »

He's right:

The coercivity of AlNiCo magnets is much lower than NdFeB magnets.
Also, NdFe magnets have a higher remanent flux density than AlNiCo magnets and ceramic magnets.

However what is not commonly known, is that AlNiCo magnets have lower coercivity than ceramic magnets, despite having higher remanent flux density.

Last, but not least, AlNiCo magnets and NdFeB magnets both conduct electricity and that makes them suffer from Eddy current losses whenever flux changes.

gotoluc · « **Reply #839 on:** April 02, 2016, 04:05:13 PM »

Thanks verpies for posting the information.

This link http://www.duramag.com/alnico-magnets/available-alnico-magnet-grades/ was posted by a youtube member. It contains details on the different Grades of Alnico manufacturing process.

He also wrote:
"Just a note, it appears that Alnico magnets require a length to diameter ratios of at least 4:1. Apparently if they are shorter relative to diameter they don't function as well. I noticed that you cut down your magnets which may be affecting the performance.

I would like a second opinion on the above.

Also, if you can think of any other kind of material which could be re-magnetized easier then Alnico please let us know.

Luc

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Author Topic: Sharing ideas on how to make a more efficent motor using Flyback (MODERATED) (Read 357362 times)

gotoluc

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