Reversible Permanent Magnet created at MIT

[spinner]

Hi, Chilean!
Good find, very interesting concept! One of a more promissing for all-permanent magnet motor builders...

Yes, if we could find a magnetic process/material,.. which would be able to change it's properties/polarisation with rather low energy input, the world would change instantly.... PM motors would become easy....

IMHO, I think it's a clever magneto-mechanical device, using a "flux-path balance" technique for apparently "very easy polarity switch".

I see Neo's and "I" pieces of EI transformer cores, with a switchable coil flux/path as a balance disturbance... There are similar concepts "in circulation", like "Flinn parallel magnetic path"....
(Or, check out the patents on "low energy magnetic switch concepts"... Steorn's patent is one of them...)

Or, I'd go with this explanation:

It looks like to me that it is simply a flux flipping device.  The two magnets are mounted opposite polarity of each other between the two short bars that are bolted together.  The bar with the coil is the 'bias' (designed like the gate of an SCR) that diverts the flux of the magnet closest to the coil to flow through the bar until interupted by a pulse of the coil.  The other magnet seeks the closest path back to itself.  The design follows that of an SCR or a logic circuit.  (The magnetic state of the switch stays like a flip-flop.  If any fairly strong magnetic source is present on the attraction bar, it might upset the delicate balance within the magnetic switch.  It might work well for a memory circuit, but probably not for a motor, unless you use only an iron core for a rotor.

Cheers!

[gyulasun]

It looks like to me that it is simply a flux flipping device.  The two magnets are mounted opposite polarity of each other between the two short bars that are bolted together.  The bar with the coil is the 'bias' (designed like the gate of an SCR) that diverts the flux of the magnet closest to the coil to flow through the bar until interupted by a pulse of the coil.  The other magnet seeks the closest path back to itself.  The design follows that of an SCR or a logic circuit.  (The magnetic state of the switch stays like a flip-flop.  If any fairly strong magnetic source is present on the attraction bar, it might upset the delicate balance within the magnetic switch.  It might work well for a memory circuit, but probably not for a motor, unless you use only an iron core for a rotor.

Hi Liberty,

In this setup ( http://img.cba.mit.edu/browse/080613_ara_reversible_permanent_magnet/DSCF6713.jpg ) and I assume you were talking about this setup,  there is no need for two permanent magnets  and in fact I believe the magnet-like metal on the left side (between the two bolts) is a soft iron core. So there is only one permanent magnet involved.

In this setup below there are two magnets indeed on the left but you can see the soft iron core piece on the magnets' right side too: 
http://img.cba.mit.edu/browse/080613_ara_reversible_permanent_magnet/DSCF6727.jpg

The operation you described is still valid: the magnet unlike poles once close through the soft iron piece (and stay there) and after the electromagnet is switched they close through the moving keeper (and stay there).

Thanks,  Gyula

[wings]

same concept?

http://www.cheniere.org/misc/astroboots.htm

wings

[Liberty]

Hi Liberty,

In this setup ( http://img.cba.mit.edu/browse/080613_ara_reversible_permanent_magnet/DSCF6713.jpg ) and I assume you were talking about this setup,  there is no need for two permanent magnets  and in fact I believe the magnet-like metal on the left side (between the two bolts) is a soft iron core. So there is only one permanent magnet involved.

In this setup below there are two magnets indeed on the left but you can see the soft iron core piece on the magnets' right side too: 
http://img.cba.mit.edu/browse/080613_ara_reversible_permanent_magnet/DSCF6727.jpg

The operation you described is still valid: the magnet unlike poles once close through the soft iron piece (and stay there) and after the electromagnet is switched they close through the moving keeper (and stay there).

Thanks,  Gyula

Hi Gyula,

Good to hear you out there.  I didn't read anything about the device, just guessed at the operation.  Just did a quick visual and threw out an opinion as usual...  Interesting device and creative.  Thanks for the description of operation.  It's good to understand things and how they work.  I always enjoy reading your posts.

Liberty

[gyulasun]

@Liberty,

Thanks for your kind words.

@Wings

Yes, I agree it is the same concept like the one shown in your link with the Radus boots. 

Unfortunately, I have not seen a decent and correct measurement on such setups like these,  probably the difficulty manifests in input pulse power measurements versus ,say, mechanical output power  (or electric output power if the steered flux is used for induction).

rgds,  Gyula