"Turn Off" a PM... Strategies

[dieter]

Hi everybody.
I'd like to discuss the possibilities in turning on and off a permanent magnet in general.


It turned out, the inability to do that is the main problem of many PMMs. So what we need is the "egg of columbus".


Let's list the options we're already aware:
(they all seem to require an external energy to do the "turn off" job, not sure about the close-loop deflection tho.)


-Electric Magnet impulse in opposite polarity.


-Heating up over Curie Temperature


-Mechanicly/dynamicly move away pm or iron.


-Mechanicly/dynamicly "shield" pm field


-close-loop pm with an external, deflecting pm or pm chain.


Any further ideas?
Thanks.

[dieter]

Do I get this right, a stack of magnets, you mean like:
__/   the slash pm could be set free by __/____ ?
If so then that's about what I meant by close-loop deflection. The stack will lower the attraction of the slash pm, but is the the attraction of the stack the same if the slash is once removed, or will it be higher?

[dieter]

Here' an other one: cooling the magnet dynamicly will result in a similar imbalance as we need it. By cooling I mean liquid nitrogen cool. So, eg. if the rotor would dip the pm into liquid nitrogen in the right moment, it may be much more pushed away than it was when it was getting closer to the stator pm before. hmmm... Would that heat up the nitrogen, Of course, but would we be back at zero energy gain? Well, by conventional physics, some flying insects are unable to fly, so...

[dieter]

Also rather interesting is the behaviour of a thin needle to a PM. When it points to the pole (in the field direction) then it has a very low attraction. when you turn it, attraction increases. How about a block of needles.

[TechStuf]

I have seen so very many attempts of this kind.  Many researchers have limited the scope of their vision by focusing all attempts at producing continuous motive force.  So much so, that it seems as if the way forward is purposely blocked to them due to singular vision.  Perhaps instead, seek not to block or "turn off" a magnetic field, but roll with it's nature and find merely novel ways of producing field "changes", such as well timed field compressions/decompressions.  One may leverage these in such a way as to isolate the magnet or ferrous material that is causing the perturbations, keeping it from getting caught in the fray.

Here is but one simple example:

Take a fairly large ring magnet, axially magnetized, and touch another magnet, also axially magnetized, at a right angle to it's periphery.  If one were to move that 'satellite' magnet in a circle, orbiting the larger ring magnet....how much friction is experienced? 

There is a 'Cheap Twist' to this simple experiment....


Somewhere.