Some Thoughts on Magnetic Shields.

[neptune]

Although I have always thought of myself as scientifically minded. I recently realised I had been very naive about something obvious. A strong magnet attracts a piece of iron. Now test the same attraction through a wooden table top, and the attraction is much reduced. I actually assumed that the wood acted as a magnetic shield. It is the DISTANCE, not the wood that reduces the effect. If it was the wood, building a perpetual motion machine would be easy.
                   Now try this simple experiment. Get a set of kitchen scales, and a pair of strong magnets. Layone one top of the scales, and fix the other on a stand, say 2cms above it, in repellant mode. Note scale reading . Now try introducing a sheet of wood or any non magnetic material into the gap. If you can cause a reduction in the reading, you have found a magnetic shield. Let me know if you do!
                 Now I know that iron will act as a shild, or at least a diverter, But any net gain is wasted in the energy needed to remove the shield after it has done its job



              However consider a second setup. A magnet is glued to the bench . A second magnet is positiond above it on the underside of a swinging arm. the magnets attract, but are restrained from meeting by a spring. Imagine a shield of soft iron in the shape of a disc, whos radius is slightly larger than the largest dimension of one of the magnets. This disc can rotate on a bearinged vertical axle, set just to side of the magnet on the bench. Imagine it like a CD disc. Now cut half of it away so it becomes a semi circle. If we now rotate this half disc on its shaft, The top magnet will bob up and down, as the attraction is shielded and unshielded. Problem is , it takes at least as much energy to move the shild as we could extract from the movement of the upper mag net .
              What if we place a Cirle of magnets under the rim of the disc? Thus we are not trying to extract the disc from a magnetic field, as it stays in the field all the time. Might it perhaps be so easy to move we could drive it from the bobbing movement of the upper magnet? Any thoughts?

[Aerny]

sounds almost plausible, but I think there are a lot of topics around here about this...

interesting though

using the overunity of gravitational induction (from the movement of the magnet), somehow, might do the trick indeed.

[Craigy]

Sounds like you are describing a lema, or low energy magnetic actuator which is a semi circle of steel covering a semi circle of magnets in its basic form.

[Liberty]

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