# COMMUNITY : FORUMS : GREEN

## Magnets, Magnetism, Field lines ???? An expert is needed for green wind power.

This is best placed in the green group as it is for the production of green electricity, but I think that it would not be out of place in the science section also.

I have an idea, quite probably not an original one but an idea all the same. It came about as we go camping as a family and have been off the grid a few times. Basically we have had no way of charging our electronic devices for longish periods. Solar power I hear you cry, well that is all well and good if you live in a country that has good sunlight, but here in the UK it can be unpredictable and not produce enough charge to power modern devices. I am mucking about with dynamo’s on the bikes (pedal ones) and wind up devices. Something I am looking into is things like wind power or improved dynamo power.

The basic principal behind all of these forms of power production is that of passing a conductor through a magnetic field to produce a potential difference on that conductor. Simples (reference to meerkat advert http://www.youtube.com/watch?v=NBu0OtC6m9g).
It has been a very long time since I have done anything like this (way back in school all those years ago) so please stick with me on this one. If I remember right the principal theory is that

1. The higher number of conductors (or loops in the coil) that passes through the field lines causes the voltage to be higher.

2. The stronger the magnetic flux the higher the current production within the conductors.
This is a bit basic to some of you I am sure but I still need to get it out to confirm my thoughts. If this is wrong please correct me, as the title says, an expert is needed lol

The bar magnet field lines project from the N end and loop back to the S end in this fashion

Image 1

Putting two bar magnets together with N and S facing gives a field pattern like this

Image 2

Now this is where I need the most help with. Toroidal magnets produce a different field pattern, and as far as I can make out from the internet it looks like this

Image 3 & 4

What I want to know is what happens when you put two toroidal magnets on top of each other, what happens to the field lines then. I have thought that there are a few possibilities on this, the first is that the circular lines will extend to encompass both magnets creating like an hour glass formation in the cross section. The second is that field lines will combine/intermingle between the magnets and create a figure 8 pattern.

In either of the two possibilities the field strength will be increased to what could be considered a focal point between the two magnets.

So with the technical thoughts out of the way and progressing on the assumption that I am correct so far my thought of a high powered dynamo is this. A central shaft that is spun by wind or other means, attached to this shaft are disks like platters on a hard drive, attached to those platters are the toroidal magnets. The magnets are aligned and spaced to give maximum condensing of the field lines between the upper and lower platter. In the centre of the two (or more) platters is a fixed platter, not attached to the shaft and is stationary. On this stationary platter are the coils, fixed into position.

Image 5

The coils are shaped and could be something like the voice coils out of a hard drive, which would be good as they would determine the size of the platters, being key stone shaped they will fit together to make a ring of coils.

Image 6

The whole idea is based upon the maximising and focusing of the field lines from the magnets to a point producing the maximum amount of energy as the coils pass through the lines. I also think that due to the shaft being turned having little resistance or weight that even small amounts of wind energy would be able to turn it to produce the desired outcome.

Now this is where I ask you all to comment and take my thoughts to bits where I have assumed things that are wrong. I have no problems being told where I am wrong as long as it is not in a nasty way.

Cheers all