Lateral force is less than pull force?

[Visionary]

The relative motion is in a horizontal direction.

The direction of the flux/field is perpendicular to the direction of the motion.

 

I'm not sure at what is the direction of the induced EMF.

 

"The part of the table where there is no flux because it is not under the bar magnet provides a retun path for circulatory eddy currents."

I think so, yeah.

[studiot]

 

The direction of the flux/field is perpendicular to the direction of the motion.

 

Perpendicular, yes but it is also horizontal.

 

Attached is a sketch of apparatus that you could use to investigate the resistance.

 

 

Edited August 23, 2013 by studiot

[Visionary]

Thank you Studiot.

Could you please explain more about the nature of this resistive force(Just to be sure)?

I assume the force generated to resist this motion, is a magnetic force of attraction?

 

I understand the factors involved in determining the magnitude of that force. But what happens when a magnet drops through a copper pipe also happens with a iron pipe(ignoring attraction force). But it's really amazing how its possible to have BOTH at the same time.

Edited August 25, 2013 by Visionary

[Visionary]

After reviewing all of this it seems to make good sense.

However, what is the issue of my previous idea? Of the air gaps... Where it could substantially increase the resistance, hence decreasing the eddy currents.

Edited August 26, 2013 by Visionary

[ox1111]

Sometimes, you need to work on the impossible. I think what you are really trying to do is create a mag motor and no you can't create an imbalance by using the magnets attraction and sliding them sideways at a lower resistance and net a gain. I am not saying it is impossible to make a mag motor, but science for the last few hundred years does. Try, it is a fun and great mental work out, but not much more.

[Visionary]

I've heard and seen multiple idea's of such a "Free-energy magnetic motor", but the good thing is.

I don't have to dig into details.

Conservation of energy is fundamental principle that makes it easier to debunk such concepts

And yes, the idea of a magnet-motor that purely uses magnet in such a way to "expect" energy from nothing or magnetic field's without any input is indeed impossible. Science is the pure study of nature, we never know what he the future holds. My statements are of previous prototypes of magnetic motors that proved C.O.E to be still valid.

But a common fact to state:

Its a known fact that the work done to slide a magnet over a surface and the work done to pull it off is the SAME, in fact! Sliding it off requires more energy because you are now doing work against friction.

A conservative field(In this case since dipoles are involved) are independent of the path taken, the work is always the same.

 

Now about the Eddy currents, there are numerous ways to decrease/increase the resistance.

To me, I wanted to discover newer methods to increase it so that the currents would be less.

 

And one of my ideas are small super tiny air gaps that have a resistance of 1.3x10^16 - 3.3x10^16, calculate what even induced EMF(V) you get, divide it by that HUGE number and you will get current(I) that is near zero... So it's really something interesting to discover/research.

[studiot]

As I said I was not available over the bank holiday but can carry on now.

 

The problem with air bubbles is that they presumabably lead to a homogenous material.

 

Entrained bubbles will also lower the susceptibility in the flux direction.

 

The point I have been trying to emphasise is that the eddy currents act in a particular direction, so you only want to change the properties in that direction.

I also noted that eddy currents are circulatory in nature. The reverse emf they generate depends upon the area of the circle. Again entrained bubbles would not reduce that area in the way that complete separation by lamination provides.

 

Finally in any material where the emf is induced by motion in a steady field, rather than a changing field, the emf is induced in all the moving material immersed in the field. You need some part of the material that is not immersed in the field for the return half of the circulatory current to flow.

Edited August 27, 2013 by studiot

[Visionary]

Welcome back.

This is really interesting, I guess we can agree that it's solvable to deal with Eddy currents now. To reduce them substantially that is.

I agree that lamination is best, on those area's where the motion is directed.

 

I just need to study how it works or how it's done.

Thank's again.

[studiot]

Sometimes we don't want to reduce the eddy currents.

 

Look up the 'eddy brake' or 'eddy brake disk'.

 

Knowing what enhances the effect can point towards reducing it.

[Visionary]

Of course it has important uses.

But I already know the potential uses of such a systems. However, never knew the methods to reduce the Eddy currents.

They can cause a lot of heat, and unwanted resistance to the motion.

[Visionary]

To note.

There is a magnetic force being applied at the edge. A magnet is placed on the edge of a steel plate, notice there is a lateral force pulling the magnet closer inward. I assume the magnetic field is trying to expand more into the ferromagnetic material.

[studiot]

 

To note.

There is a magnetic force being applied at the edge. A magnet is placed on the edge of a steel plate, notice there is a lateral force pulling the magnet closer inward. I assume the magnetic field is trying to expand more into the ferromagnetic material.

 

I'm sorry I don't follow what this is referring to.

[Visionary]

We agreed that there are no magnetic force's acting when moving horizontally.

Because the magnetic force act's only perpendicular to the surface.

 

I noticed when moving a magnet over a ferromagnetic surface, only force resisting me is friction. But when I get to the edge,and the magnet is off-set I feel a strong magnetic force attracting the magnet back.

 

There is indeed a weak lateral magnetic force, only at the edge.

I'm wondering how could there be a magnetic force laterally and strong at the edge?