Electromagnet power transfer question.

[nwman]

I'm currently researching the properties of a toroid and I was wondering if you could help me answer a few questions that I have. So from that I have found a Toroidal magnetic field travels in a loop inside the circle of the core and is relatively self shielded. Meaning that if you touches a piece of metal to the side of it while it was on, that piece of metal would not be attracted to it?

http://www.youtube.com/watch?v=MjcdJ1wSQJI
http://www.youtube.com/watch?v=edqGNOrW1GM
http://en.wikipedia.org/wiki/Toroidal_inductors_and_transformers

Also, a toroid is another type of transformer correct? So if you have two windings on a toroid or primary and one secondary you can input/output power with minimal loss just like a normal transformer?

The last question I have is if you have a toroid that's powered would a magnet be attracted to it or what might be the interaction?

Tim

[Nali2001]

Hi Tim,
Yes a Toroidal core or O-core is for transformers and such. It has better characteristics than the 'normal' E I type "square" transformers since there are less losses and the geometry is optimized. Normal transformers are made or 2 parts welded together. This introduces a small airgap loss and due to the weld you also increase the eddy current losses. So normal transformers are more leaky then O-core transformers. Another advantage is that O-core transformers are made wound from a long grain aligned strip of transformer steel. This also causes them to have a higher saturation limit. But.... they are hard to wind then therefore not used very often.

If a piece of metal is interacting with a working transformer it means that the transformer is leaking.

Yes a magnet will still be attracted to a ('any type') transformer even if highly saturated since the steel is still attracting and also there is a less known thing about transformers/magnetism and that is that they can have a magnetic field independent in all 3 axes (X Y Z) due to the spin theory of magnetism. That means you can wind on a suitable core in each axes a transformer coil arrangement and have them working independent from each other. So independent transformers on one core. As long as there is only one transformer per X,Y, or Z axes. Therefore a core is only really saturated when saturated in all the 3 axes. With normal transformer windings they are only magnetized in one dimension/orientation. To learn more about this you could see this patent:
http://www.google.com/patents?id=nDA3AAAAEBAJ&printsec=abstract&zoom=4&dq=4210859#PPA1,M1

Regards,
Steven

[nwman]

How can the Bulgarian system work [theoretically] if the magnetic field of the magnets are still attracted to the toroid? I thought the idea was that the saturation of the toroid blocked the field of the PM so the PM field would go a different rout?

Tim

[Nali2001]

The field of a magnets must always close loop and follow the path of least resistance. Although the material might still be 'attractive' for the magnet it can not 'host' the field of the magnet. It is already 'full' of magnetism and can not support more. Hence the term saturated. So in the saturated state, it is not a 'path of least resistance' Don't confuse magnetic attractiveness with the ability the support the fields. A paper clip is also attracted to a magnet but can not support the fields.

[nwman]

Thanks Steven! That's what I had thought but I wasn't sure. I appreciate your time and input.

So now what about the problem of the core touching the toroid at the top and bottom? Would this have a large effect on the loss from the toroid? [I do plan to test these ideas for myself but I just want to see what I can find out in advance.]

Could you run the toroid like a transformer and collect the AC back out with minimal loss while still saturating the core?



It seems that if you can use the toroid like a transformer with two separate coils [primary/secondary and recover 90%+] and the toroid would saturate the core enough to cause the PM flux to divert and jump the air gap then this would be a better design. A little more complicated but like you said it could run off AC. Compared to Jack's valve it would have less flux field generated since Jack's is estimated at up to 4 time increase and the Bulgarians would only be the strength of just less then the PM field. Correct?

What other problems would there be?

Thanks,

Tim