Perm. magnet only core with iron shell, motor coil

[synchro1]

Naturally, increasing magnet strength would increase Lenz drag, but the net result would equal more output per unit of input.


Look at Art Porter's GAP. His electromagnetic coil equals the magnetic strength of the permanent magnet backing it up, so that it's power can match and mask the PM field with an opposite charge;


Then the repulsion doubles over what it would be with the electromagnet alone when the current's reversed. Horse sense can probably tell us as much as Art's sketchy COP measurements.    

[tim123]

Hi Synchro.
  I think the Lenz drag is exactly equal to the change in flux. So a stronger magnet provides exactly the same amount of output - just in a smaller package.

So a stronger magnet would not equal more output per unit of input (ignoring friction etc), it would be exactly equal. The counter-force in any generator is provided by the load.

The GAP power device isn't OU. I spent some time playing around with that setup - it taught me lots - but it's not OU.

It takes exactly the amount of energy to cancel the field of a PM as you can get back from it - if you're just placing a coil in front of the PM. I've tried it. In fact - there are losses.

I think it's true to say: If your magnets face the coils directly - it's never going to be OU - because of Lenz's law.

[Floor]

@Kator01

Thanks for posting the gap motor link.  Interesting design.

I was not familiar, with the "gap motor".  And yes there is a similarity between the gap design, and the
mag core/iron shell design.  However, the gap design requires electrical input equal to the perm magnet strength, to neutralize the perm magnet. No net gain.

The goal of the mag core/iron shell design, is to create a mag field in the iron shell, only when the coil is on.  And to contribute to that field with the mag field from the perm magnet core.

Thanks very much again for your post.

                           cheers
                                  floor

[tim123]

Hi Floor,
  this arrangement might work. Diagram below:

- The steel core surrounds the magnet & provides a complete magnetic circuit - so the flux doesn't leave the core.
- The coil surrounds the steel core.
- When the coil is powered up, the same polarity as the magnet, it saturates the steel core so that return path isn't available.
- So the effect should be to have the flux of coil + core + PM on the outside of the core.

I'm not sure if this would give you more magnetic force for a given electrical input though... It may be that it takes extra current to saturate the steel, with the PM inside it...

Regards
Tim

[Floor]

@tim123

Thanks for the suggestion. 

Your drawing is a variation of the gap motor design, but a stimulating idea.

If the permanent magnet within the iron shell, were kept isolated from the iron shell, (not in physical
contact with, and only partially in a "magnetic contact" with the iron shell)  then the principle would be similar to the
electro permanent magnet (EPM) concept. 

             Thanks again

                  cheers
                       floor

                          PS

                               I'm still busy with measurements on the 1.5 : 1 all magnet design/testing