Magnetic fields within a toroid inductor.

[MileHigh]

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.

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]

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]

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]

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.

A vector field

[poynt99]

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.

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.

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.