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Author Topic: Magnetic fields within a toroid inductor.  (Read 93758 times)

MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #30 on: September 14, 2013, 07:59:09 PM »
That's great "proof" there Dave45, a glass container filled with ice.  Is your next step going to be designing an infinitely impossible anti-gravity drive just like on the Hitchhiker's Guide to the Galaxy?

MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #31 on: September 14, 2013, 08:03:52 PM »
Webby1:

Quote
What if the core for a toroid was not a closed loop?  Could you then measure the current and factor in the "lossy" state of the core?

I have a testbed or 4 that are setup this way and there is a field emanating from it as well as one can be introduced as such to generate an output from the winding, so I am thinking this is not a "valid" way to test."

I am honestly not sure what the context is for your first two questions.  Can you elaborate a bit?

MileHigh
 

Dave45

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Re: Magnetic fields within a toroid inductor.
« Reply #32 on: September 14, 2013, 08:04:16 PM »
The A vector field can be spun........... if you know how


Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #33 on: September 14, 2013, 08:46:59 PM »
Hey Dave

How much power goes into your coil when you freeze the water?  Is it AC?  Have you tried it with just a magnet?

Mags

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #34 on: September 14, 2013, 09:39:14 PM »
Here is another oddity found today,while looking into field strength over P/in of the rotor of the new high powered pulse motor project-the Altipulse.
Now we all know how an alternator works-right?.
Well in this video,i seem to be missing one polarity of the magnetic field???.
http://www.youtube.com/watch?v=t5nrlGpCB9I

What a great effect you are showing here.  ;)   I wonder if a speaker magnet would do the same. If a speaker magnet did not cause the effect, then possibly a speaker magnet would work better.

What your video shows is that there is a difference  between S and N poles possibly when using a coil as compared to a magnet, or, there is an effect going on with the outer circumference of the coil and the pole fingers that is not commonly known. The speaker magnet test would be a step in the right direction. There are vids on YT that show how to take apart the armature to remove the coil to install magnets.  If there is a difference and the magnet causes the screw driver to be attracted to N and S fingers, then the coil has different attributes than a magnet of similar size and shape. I know they do, but the effect you show, Im not familiar with and it interests me.  ;) Thanks for showing.

Mags

The reason they dont use magnets instead of coils is the regulating of the output is done by the regulator adjusting the voltage to the armature coil. Recent years there are permanent mags in alternators, as rare earths can handle some heat and the regulation is controlled at the output.

Dave45

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Re: Magnetic fields within a toroid inductor.
« Reply #35 on: September 14, 2013, 10:40:39 PM »
I just showed you the secret of the ages and you dont even realize it  ;D ;D ;D

xee2

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Re: Magnetic fields within a toroid inductor.
« Reply #36 on: September 14, 2013, 11:08:20 PM »

tinman,


I have worked with toroids and magnetic field theory for over 30 years and I have always found the description given in the link suggested by MileHigh


http://www.youtube.com/watch?v=pCSHcftPAIM


to be correct. This is the standard physics/electronic engineering theory approach. The PDF suggested by Magluvin


http://www.overunity.com/13802/magnetic-fields-within-a-toroid-inductor/dlattach/attach/127516/


gives a simpler explanation that is also correct.


These explanations may not be the ultimate truth, but they have been used successfully by physics and electronic engineers for many years.


I recently posted a video you may find interesting about flux cancellation that has experimental tests showing magnetic field cancellation in a toroid (however, I admit it was not easy to understand):


http://www.youtube.com/watch?v=sc9bt5Yo0H8




Dave45

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Re: Magnetic fields within a toroid inductor.
« Reply #37 on: September 15, 2013, 12:33:42 AM »
Keep on trucken


MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #38 on: September 15, 2013, 03:00:01 AM »
Tinman:

I did a little bit of hunting around and now know that you were looking at the rotor of an alternator (Just like you stated but for some reason it didn't register with me at first).  In the schematics I looked at I did not see any rotors that had two separate energizing circuits for the North and South finger pole electromagnet coils so it's still a mystery to me.  I see how a voltage regulator circuit governs the amount of DC current that goes into the rotor electromagnets via the slip rings and that will then determine the rectified voltage output from the stator windings.

Good doc:  http://www.autoshop101.com/forms/alt_bwoh.pdf

Good graphic:  http://forums.pelicanparts.com/uploads9/mot_alt1168989977.gif

If anything there are lots of diodes, but I can't explain your screwdriver test.  I can only suspect that there are some diodes embedded in your rotor as per the diodes you see that allow the stator to take over the job of energizing the rotor electromagnets once the alternator is spinning.  Perhaps for some reason there are separate circuits to energize the North and South finger poles in the particular rotor you were examining.  However, that still doesn't explain the effect you see when you reverse the polarity.  Although when you think about it, I am assuming that the polarity for the voltage on the slip rings is not supposed to be reversed.

I was the type of kid that opened up everything to see how it ticked.

MileHigh

poynt99

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Re: Magnetic fields within a toroid inductor.
« Reply #39 on: September 15, 2013, 03:00:08 AM »

I strongly disagree.  :P

There are fields in that open area.
Mags,
Correct, but it is not a magnetic field.

Quote
Lets take the toroid diagram in the vid and make it a transformer. Primary on the left and secondary on the right. Now, if the primary induces a field in the core, how does the secondary get induced if the field is only in the core? ???   
It's quite easy to understand how, but you first have to understand that a changing flux (B-field) creates a changing electric E-field, which is at 90º. Second you need to be aware that the E-field is present both inside and outside the toroid. Third, you need to understand that it is actually the E-field which is responsible for both self and mutual induction. Fourth, the B-field inside the core is conducted from the primary through to the secondary due to the high permeability core.

Quote
The field of the primary has to 'cut' the windings of the secondary.
When using a toroid core, no it is not required. What is required is that the flux created in the core by the primary, must go through the center of the windings of the secondary, the same way you can make a transformer by placing two coils side-by-side on a rod core.

Quote
If you put a wire through the very center of the toroid opening,not even touching any toroid windings or the core, you will get current induced into that wire from an input to the toroidal coil. So how can that be, if the field is only in the core? ??? ?
It is not only normal for this to be the result, but it is required. It must occur. But as I mentioned, you must be aware of and carefully consider the E-field in this interaction. When you see this, it is simple and obvious.

Ask questions if you are still not clear on what I'm saying.

MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #40 on: September 15, 2013, 03:33:10 AM »
Dave45:

You are certainly welcome to add some substance to your pictures and just state in plain language what you are alluding to.  To be honest you are showing the same pattern that we see from BruceTPU and Jbignes5.  It's the pattern of dropping comments and hints that imply that you guys are "in the know" and "big things are coming" but there is never any substantive information provided to back up the hints and the teases.  I am challenging you to break that pattern.

Quote
The A vector field can be spun........... if you know how

What do you mean and how do you do it?  Please share your knowledge because you are implying that you know something that we don't.  What is that knowledge?  Please don't make a comment that's just another hint or a tease.

You show a picture of a spool of wire with some funky windings.  What is that spool for?  Why are the windings like that?  What are your expectations with that design?  Have you made any measurements?  What are the measurements?  How did you make them?  What do they mean?  What are the input signals and what are the output signals?  If you are working with a power output vs. power input scenario, what is the power source and what is the load that you use for your output power measurement?  Precisely how do you make your input power measurement and precisely how do you make your output power measurement?  I am asking you for straight facts if you have them, and not some link to some Tom Bearden stuff or some other page filled with alternative theory.

Please just give us the real deal without any smoke and mirrors if you really have something.

Thanks,

MileHigh

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #41 on: September 15, 2013, 03:41:40 AM »
Mags,
Correct, but it is not a magnetic field.
It's quite easy to understand how, but you first have to understand that a changing flux (B-field) creates a changing electric E-field, which is at 90º. Second you need to be aware that the E-field is present both inside and outside the toroid. Third, you need to understand that it is actually the E-field which is responsible for both self and mutual induction. Fourth, the B-field inside the core is conducted from the primary through to the secondary due to the high permeability core.
When using a toroid core, no it is not required. What is required is that the flux created in the core by the primary, must go through the center of the windings of the secondary, the same way you can make a transformer by placing two coils side-by-side on a rod core.
It is not only normal for this to be the result, but it is required. It must occur. But as I mentioned, you must be aware of and carefully consider the E-field in this interaction. When you see this, it is simple and obvious.

Ask questions if you are still not clear on what I'm saying.

Hey Poynt

So are you saying that the transfer of induction between the primary and secondary on a toroid core is via the E-field, not 'electromagnetic induction' ?   

Is the E-field a product of the magnetic field, not a product of voltage applied to the coil?


"What is required is that the flux created in the core by the primary, must go through the center of the windings of the secondary, the same way you can make a transformer by placing two coils side-by-side on a rod core."

When you say "through the center of the windings", do you mean that flux in the inner area of the toroid core. cuts across that area to cross the secondary?

Thanks ;)

Mags

tinman

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Re: Magnetic fields within a toroid inductor.
« Reply #42 on: September 15, 2013, 04:17:21 AM »
tinman,


I have worked with toroids and magnetic field theory for over 30 years and I have always found the description given in the link suggested by MileHigh


http://www.youtube.com/watch?v=pCSHcftPAIM


to be correct. This is the standard physics/electronic engineering theory approach. The PDF suggested by Magluvin


http://www.overunity.com/13802/magnetic-fields-within-a-toroid-inductor/dlattach/attach/127516/


gives a simpler explanation that is also correct.


These explanations may not be the ultimate truth, but they have been used successfully by physics and electronic engineers for many years.


I recently posted a video you may find interesting about flux cancellation that has experimental tests showing magnetic field cancellation in a toroid (however, I admit it was not easy to understand):


http://www.youtube.com/watch?v=sc9bt5Yo0H8
Hi xee2
Thanks for the video.
As you have shown,it seems that those that argue there case,are infact showing much the same thing-I think MH actualy pointed this out some time back.

I have a new thought on a toroid transformer,based around the given information here on this thread. So i will cast a metglass core today,and wind it tomorrow-and see what happen's.

Dave45

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Re: Magnetic fields within a toroid inductor.
« Reply #43 on: September 15, 2013, 04:31:25 AM »
Mags,
Correct, but it is not a magnetic field.
It's quite easy to understand how, but you first have to understand that a changing flux (B-field) creates a changing electric E-field, which is at 90º. Second you need to be aware that the E-field is present both inside and outside the toroid. Third, you need to understand that it is actually the E-field which is responsible for both self and mutual induction. Fourth, the B-field inside the core is conducted from the primary through to the secondary due to the high permeability core.
When using a toroid core, no it is not required. What is required is that the flux created in the core by the primary, must go through the center of the windings of the secondary, the same way you can make a transformer by placing two coils side-by-side on a rod core.
It is not only normal for this to be the result, but it is required. It must occur. But as I mentioned, you must be aware of and carefully consider the E-field in this interaction. When you see this, it is simple and obvious.

Ask questions if you are still not clear on what I'm saying.


 8) A vector field

poynt99

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Re: Magnetic fields within a toroid inductor.
« Reply #44 on: September 15, 2013, 05:36:13 AM »
Hey Poynt

So are you saying that the transfer of induction between the primary and secondary on a toroid core is via the E-field, not 'electromagnetic induction' ?   
The idea is to understand that there is a changing (increasing and decreasing) B-field within the core. This changing B-field is created by the primary coil and is "conducted" all the way around the core by the core material. Since the secondary happens to be in the direct path of this changing B-field, the resulting changing E-field around the secondary (in the same plane) causes the secondary induced emf.

Quote
Is the E-field a product of the magnetic field, not a product of voltage applied to the coil?
Correct. The E-field is a product of the changing magnetic field. The changing magnetic field from the primary is caused by current in the primary, which of course is caused by voltage applied to the primary coil.

Quote
When you say "through the center of the windings", do you mean that flux in the inner area of the toroid core. cuts across that area to cross the secondary?
I mean that the flux "travels" around via the core to the secondary, where it goes through the "hole" of the secondary coil.

There is an E-field produced at every point around the toroid (perpendicular to the B-field), no matter if there is a coil situated there or not. When we properly place a coil in the path of the B-field, the coil "intercepts" the resulting E-field and hence has an emf induced in its windings.