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LAN_403

Psyko

Sat Nov 25 2006, 07:44PM

Registered Member #81 Joined: Thu Feb 09 2006, 11:57AM
Location: Paris, France
Posts: 43

Has anybody hacked this thing to see what is inside, because it seems really innovative. Two french guys have apparently developped that system.

Dr. Slack

Sat Nov 25 2006, 09:24PM

Registered Member #72 Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659

At 70 EUR, you can buy one, I'll take the can-opener to it

Tesladownunder

Mon Nov 27 2006, 12:12AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

That's just the effect I want to create.
My guess is that it has a NIB magnet in the globe and the weight distribution in the globe prevents it flipping. A central NIB magnet in the base provides the main levitation force and lateral drifts are prevented by compensating coils as per normal magnetic suspension circuits with only modest power consumption.
At least I know it can be done.
Nice.

Peter

Coronafix

Mon Nov 27 2006, 02:32AM

Registered Member #160 Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938

No. This is the device that I spoke of in the Laithwaite book, Propulsion without wheels.
The text says that it has constant rotation and is driven by 220v.
The globe will be hollow aluminium, and the base will have the specially
wound elecromagnet that Laithwaite shows in his book.
It's just a different kind of linear induction motor.

cbfull

Mon Nov 27 2006, 11:35AM

Registered Member #187 Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140

Aluminum tends to heat up and eventually melt when levitated with an AC field.

I found another page that shows a variety of objects being levitated as a result of a permanent magnet attached to the object (or inside a globe at the bottom). There is no suspension circuit, so there is nothing above the globe.

There are two designs that I recognize, one uses opto sensors, and the other uses hall-effect sensors.

Take a look for yourself:

Coronafix

Mon Nov 27 2006, 11:55AM

Registered Member #160 Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938

mmm...nice. But it does not accommodate for the rotation unless manually rotated.
I think the field strength to size of aluminium would have a lot to do with it not melting.
The spherical geometry is the key to the stability. The induced field(s) in the sphere are uniformly spread around it.
Perhaps a mix of the two? A permanent magnet inside a aluminium sphere?
I seem to recall the rotating sphere needing two linear coils, one inside the other, but it was at least five years since
I read the book.

Carbon_Rod

Wed Nov 29 2006, 03:06AM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

I think it is purely a centre of gravity trick with a small magnet on the high point. The $79 EU coil keeps aloft buy a simple unregulated field..

Teslaâ€™s egg experiments shows what happens if even a small defect is in the sphere. See the video (yes it will work in VLC),

Cheers.

]1164769569_65_FT18397_tesla_egg.avi[/file]

cbfull

Sun Dec 03 2006, 04:23AM

Registered Member #187 Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140

Carbon_Rod wrote ...

I think it is purely a centre of gravity trick with a small magnet on the high point. The $79 EU coil keeps aloft buy a simple unregulated field..

I'm not sure I understand what you mean. Do you mean that the stability comes from the weight of the globe "hanging" underneath the perm magnet?

If you click on the "photos" tab at the top of the page you can see an example of the circuit running with a clear globe, and the magnet is in the bottom.

Sorry if I misunderstood.

Carbon_Rod

Mon Dec 04 2006, 12:14AM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

â€œI'm not sure I understand what you mean. Do you mean that the stability comes from the weight of the globe "hanging" underneath the perm magnet?â€

As I do not own one -- I would not know exactly how it works. However, some suggested an aluminium sphere which is probably not a critical part of the mechanism. The levitating conductive sphere demonstration is an entire thread unto itself.

â€If you click on the "photos" tab at the top of the page you can see an example of the circuit running with a clear globe, and the magnet is in the bottom.â€

The link at the top of the page has a bump on the top of the sphere (only have to accelerate the sphere at g to prevent falling). However, a magnet held in position with a feedback sensor and a strong enough field can easily hold. Note the second linkâ€™s control system is overly complex in many regards even for a maglev system. Many people here have build far simpler systems that work well.

Cheers,

DrZoidberg

Mon Dec 04 2006, 07:32PM

Registered Member #350 Joined: Mon Mar 27 2006, 05:14PM
Location:
Posts: 106

That looks nice. I always wanted to build a maglev system where the electronics is mounted below a table and therefore not visible and the globe hovers several cm above the table. That should look impressive.
But how do I build that?
On that website above the picture of the clear sphere it says "the poles plane of levitated magnet have the tendancy to stay parallel to the poles plane of sustentation magnets and this property is reinforced by the control of the position for witch the stability is amazing."
I'm not sure I understand the working principle. In my experience two magnets that repel each other don't have the tendency to stay parallel to each other.

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