Magnetic Engine Video

[vineet_kiran]

The magnet is attracted by the shield, but the fixed magnet is repelling. The combination makes the repelling force weaker.

Vidar

Fixed magnet will not repel the pendulum if it is totally covered by the shield. That is the basic idea of using the shield.  Even if stray flux escapes out of the shield and repels pendulum, it is not of any concern because this force will be neglible.


I don't know whether you people are trying to test my knowledge or showing your ignorance. (foolishness?)

[Low-Q]

Fixed magnet will not repel the pendulum if it is totally covered by the shield. That is the basic idea of using the shield.  Even if stray flux escapes out of the shield and repels pendulum, it is not of any concern because this force will be neglible.


I don't know whether you people are trying to test my knowledge or showing your ignorance. (foolishness?)

You cannot shield magnetism, but you can make it take another path. In this case, parts of the magnetisn from the fixed magnet takes a short cut through the steel plate and directly back to the magnet again, so less magnetic field is repelling the pendulum magnet. The pendulum magnet also "see" this steel plate and will attract to it. Since the magnetic field is only partially guided through the steel plate, there is still surrounding field that still repels. There is not parallell magnetic flux between the magnet when they repel.
While the pendulum magnet and the fixed magnet is closer, there is now more magnetic flux goung through the steel plate, so it will take force to guide this steel plate away from the gap between those magnets. When you start removing the steel plate, the force will result in energy loss - force * distance is energy.
On the contrary, if the magnets was attracting, it would be more parallell magnetic "lines" between the magnets. If the steel plate was placed exactly in the middle between these magnets, it would take less effort to remove the steel plate. In fact, the steel plate would then repel from the magnets when it is outside the gap between the magnets - considered that those magnets keeps the gap.


I know this by experiments. I will shortly put a video on youtube demonstrating this. So you'll learn how magnetism work in your design.


Vidar.

[MarkE]

Can you please explain what this has to do with the experiment?

You perform work moving your "shield". 

The nerves in your hands should be telling you that it is harder to move your "shield" back and forth when there is a stack of magnets on one side of the ball than a similar sized block of unmagnetized metal.

[Low-Q]

Here is a video. Simple experiment showing that iron will be "hard" to pull away from the field between two opposing magnets.
This will take energy by the same amount as the gain in the pendulum magnet. However, I did not make the pendulum magnet, just two opposing magnets I try to remove the shield away from.


http://youtu.be/bcQfMGakGQc


Vidar

[Low-Q]

This is a simple experiment without involving any cost. Why don't you build it as it is and verify it?

I can try. I have most of the hardware and tools to make one - just for educational purpose. The video above is highly simplyfied.


Vidar