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Author Topic: Magnetic fields within a toroid inductor.  (Read 93411 times)

tinman

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Magnetic fields within a toroid inductor.
« on: September 11, 2013, 04:01:30 PM »
So what dose the magnetic field look like within a toroid coil?. Is the magnetic field contained within the toroid core?,and wich field is it-north or south?.
My first test looking at a field being expelled outward from the toroid coil.But listen carefuly to the video near the end.
http://www.youtube.com/watch?v=WNOtEDkCSpA

conradelektro

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Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #2 on: September 12, 2013, 01:06:29 AM »
This PDF explains it quite clearly as to how the fields propagate through a toroid core and coils. I believe it is correct.  ;) Its only 18 pages.  Read carefully, and you will get the picture. ;D

Mags

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #3 on: September 12, 2013, 02:21:52 AM »
Sorry. Hit quote instead of modify to correct spelling of 'cor' to core. ;)   Too bad there wasnt a delete feature that had like a 1 min time frame in which to do so if a mistake were made such as I just did.

Mags

Cap-Z-ro

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Re: Magnetic fields within a toroid inductor.
« Reply #4 on: September 12, 2013, 03:22:06 AM »
Just click the 'edit' button and remove all you want deleted.

If you wish to delete all text, remove all but the 'period', and click save...and bob's yer uncle.

Regards...



MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #5 on: September 12, 2013, 03:44:34 AM »
Tinman:

With the application of Ampere's Law and by drawing an Amperian loop inside a toroid you can derive the formula that tells you what the magnetic field strength inside a toroid is.

Quote
In classical electromagnetism, Ampère's circuital law, discovered by André-Marie Ampère in 1826,[1] relates the integrated magnetic field around a closed loop to the electric current passing through the loop. James Clerk Maxwell derived it again using hydrodynamics in his 1861 paper On Physical Lines of Force and it is now one of the Maxwell equations, which form the basis of classical electromagnetism.

The real thing:

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

Quote
Is the magnetic field contained within the toroid core?,and wich field is it-north or south?

I have posted several times recently that there is no such thing as a "North field" or a "South field" when it comes to a magnetic field.  You have to wrap your mind around that one to understand magnetic fields.

MileHigh

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #6 on: September 12, 2013, 03:47:59 AM »
Hey Cap

Yeah, I thought of just deleting all. But then there is a post that is blank, leaving some thinking, what was he going to say, but didnt? So I usually say something when it happens. ;)

Mags

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #7 on: September 12, 2013, 04:39:53 AM »
Tinman:

With the application of Ampere's Law and by drawing an Amperian loop inside a toroid you can derive the formula that tells you what the magnetic field strength inside a toroid is.

The real thing:

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

I have posted several times recently that there is no such thing as a "North field" or a "South field" when it comes to a magnetic field.  You have to wrap your mind around that one to understand magnetic fields.

MileHigh


I strongly disagree.  :P

"The real thing:

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

At 5:40, and I was waiting for this, listen to what he says about fields in the hole of the toroid.

There are fields in that open area. This is where the windings have mutual inductance. This is where fields of each winding are able to 'cut' other windings or turns of the coil in order to have mutual inductance. The pdf I posted above explains it quite perfectly and it describes 'why' those fields could not possibly only remain in the core, which is very important to understand. ;)

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? ???  The wire does not have 'feelers' out there that detect if a field is 'locked' in the core. The field of the primary has to 'cut' the windings of the secondary. It is basic mutual induction. So why is that not explained in the video???   The pdf in my previous post, and I will repost it here, explains it perfectly.  Dont get board with the pdf. Its 18 pages and it should be read till it is understood as a whole. It corrects the problem of the ideas presented in this vid posted by Milehigh. 

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? ??? ?

There are many vids on YT that show this 1 wire through the middle. ;)




Mags

MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #8 on: September 12, 2013, 05:43:03 AM »
I told you that I don't want to have any interaction at all with you and I mean it.

Don't interact with me at all.

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #9 on: September 12, 2013, 05:51:28 AM »
I told you that I don't want to have any interaction at all with you and I mean it.

Don't interact with me at all.

Whatever dude.

That vid you posted is malarky with math to explain the malarky. People deserve the truth, and that vid isnt it. I was wondering if the vid would get into those facts and surprisingly it did. ;)

Yeah, you PM'd me. And I didnt respond. If I see you preaching garbage, I will respond. And I did. I will post where ever I please.  :P Try to get me banned on that. ;D :P

Mags

MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #10 on: September 12, 2013, 05:58:50 AM »
The posting below is primarily about you and I don't want to interact with you, period.

I can relate to the detractors and enemies schtick too.

I have had people say to ignore all my postings because I am supposedly an extremist.  I have had people relentlessly bash me for days and days and days, picking apart anything I say trying to twist it into something bad.  People that personally attack me over and over.  People that say that I am "polluting" the threads.  I once tried to explain to someone how to test their transistor because after two years of building pulse motors the only thing that he could do was make sure the wire lengths were equal. (??)  Then that person had a total freak-out on me and went ballistic.  I have been bashed over and over because I don't show any bench work yet in my educational and professional life I have spent literally thousands of hours on the bench.

And the ironic thing is that with good intentions and without malice I am simply trying to tell people the truth and I try sometimes to educate them.  I am not perfect and I can't always speak in politically correct prose so as to not offend someone that in reality has no clue whatsoever about what they are trying to do.  It's too easy to claim that you have a fragile ego and cry that you are being belittled when in fact that's not the truth.  When I sometimes make a really good suggestion the response is mute silence.  If a beginner that barely knows what he or she is doing makes the same suggestion, they are heaped with praise.

What irks me the most is the peer pressure among the forum members themselves.  I coined a term for it, "Orwellian stagnation."  If an outsider comes to the forum with a crazy proposition many people will challenge the person.  But if an insider to the forum makes a crazy proposition, then in the majority of cases nobody will say anything.  And I have seen things posted on this forum by insiders that are ridiculous and counter-productive for people that are trying to learn something.

The bottom line is that I will stand my ground.  Anybody that thinks that I am a "bad guy" because I speak the truth to the best of my abilities is wrong.  This notion that I am "demeaning and belittling people" is driven by the ego issues of others, because I don't consciously make an effort to demean and belittle people.  On the flip side, I have seen many people consciously and maliciously demean and belittle me - without merit - and it all stems from their own frustrations.

You indeed have to have a thick skin sometimes.  I have no problem having thick skin.  But if somebody is going to maliciously and relentlessly go after me and try to make my life miserable I will push back.

MileHigh

You stay the fuck away from me.

MileHigh

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Re: Magnetic fields within a toroid inductor.
« Reply #11 on: September 12, 2013, 06:08:12 AM »
The YouTube user Lasseviren1 is a science teacher and was gracious enough to post about 200 videos covering physics, dynamics, electrostatics, electricity and magnetism, etc.

http://www.youtube.com/user/lasseviren1/videos

That's where the clip I posted about the toroid's magnetic field comes from.  The guy is great and if you look at his first few clips he explains derivatives and integrals.  So if you get that then you should be able to follow his nice clear "paper talk" explanations using paper and a marker.  He knows his stuff, he is a great communicator, and I encourage people to look at his clips.

He does several examples of using Ampere's Law to solve for the magnetic field for various configurations, the toroid example is just one of them.

MileHigh

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #12 on: September 12, 2013, 06:10:48 AM »
Stand your ground all you want. I expect nothing less from anyone here. It is everyones right. ;)

Instead of talking about the issues presented by me, well, look at your replies above.

I tell you what. If you read the itty bitty pdf and can give a reasonable dispute of its claims, of which contradict the video you posted, I would be willing to have that discussion on good terms.

I know you are trying to teach people here. But with facts like that, ones that would have Tesla laughing in his grave, someone needs to set the record straight. And on this, I stand my ground. Unless you can undeniably refute my stance on this thread subject with substantial evidence, not circumstantial. Can you do that?? ;)

Mags

Magluvin

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Re: Magnetic fields within a toroid inductor.
« Reply #13 on: September 12, 2013, 06:25:38 AM »
The YouTube user Lasseviren1 is a science teacher and was gracious enough to post about 200 videos covering physics, dynamics, electrostatics, electricity and magnetism, etc.

http://www.youtube.com/user/lasseviren1/videos

That's where the clip I posted about the toroid's magnetic field comes from.  The guy is great and if you look at his first few clips he explains derivatives and integrals.  So if you get that then you should be able to follow his nice clear "paper talk" explanations using paper and a marker.  He knows his stuff, he is a great communicator, and I encourage people to look at his clips.

He does several examples of using Ampere's Law to solve for the magnetic field for various configurations, the toroid example is just one of them.

MileHigh


I still say what was in the vid is incorrect when it comes to saying there are no fields in the doughnut holes of the core. The pdf explains it perfectly. You should really look at it. ;)

I would like to here the guys explanation of how a secondary as I described in my previous post could be induced by a field from the primary if 'all' of the field is locked in the core. ;) ;) ;) ;)
I would really like that. ;D


Mags

Farmhand

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Re: Magnetic fields within a toroid inductor.
« Reply #14 on: September 13, 2013, 03:46:46 AM »
Yes Mr Eric Dollard is confused by toroidal transformer induction and says no one knows how it happens.  ;D  So I linked that PDF at EF maybe over 1 year ago.  ;) In response to mbrowne.

Although I think it is theoretical.

I think bench tests are in order.

Cheers