What is the maximum height a magnet can hover in a magnetic levitating globe?

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Discussion Overview

The discussion revolves around the mechanics of a magnetic levitating globe, specifically focusing on the maximum height a magnet can hover above a base electromagnet. Participants explore the principles of magnetic levitation, the role of current and voltage, and the materials involved in constructing such a device. The conversation includes both theoretical considerations and practical implications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that increasing voltage may not be effective for raising the height of the magnet and emphasizes the need to increase current instead.
  • Another participant warns that increasing current could lead to instability in the system and potential overheating of the coil.
  • A participant speculates about building a larger version of the globe and questions how high it could levitate if current were increased, while also considering the limitations of overheating.
  • Questions are raised about the nature of the electromagnet, including whether it is truly toroidal and how the magnetic field interacts with the globe's magnet.
  • There is a discussion about the suitability of materials for the coil, with copper being favored for its conductivity, while silver is mentioned but deemed impractical due to cost.
  • Some participants express uncertainty about the design and functionality of the levitating globe, particularly regarding the stabilization system and the behavior of the magnet within the globe.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the mechanics of the levitating globe, the effectiveness of increasing current versus voltage, and the nature of the electromagnet. The discussion remains unresolved with no consensus on several technical aspects.

Contextual Notes

Participants acknowledge limitations in their understanding of the system, including assumptions about the materials used and the design of the electromagnet. There are also unresolved questions about the specific mechanisms of levitation and stabilization.

Who May Find This Useful

This discussion may be of interest to hobbyists exploring magnetic levitation, individuals curious about the physics of electromagnets, and those considering DIY projects related to magnetic levitating devices.

magiktcup
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Layman speaking here..

I have for a while been interested in a small desk toy. It is a magnetic levitating globe.

There is a doughnut shaped electromagnet at the base which according to the internet is a toroid. Within the globe sits a disc shaped neodymium magnet.

The globe hovers barely a cm above the base.

What i am interested in is how high could you actually get the magnet to hover?
If you increase the voltage would it increase the magnetic field and raise the height of the magnet?

Any assistance in explaining this would be appreciated,
i promise i will use this knowledge only for good.

Thanks
 
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No, you need to increase the current not the voltage.
 
magiktcup said:
If you increase the voltage would it increase the magnetic field and raise the height of the magnet?
Maybe, but it could also make the system unstable. Also, the system needs active stabilization which could fail. In addition, a higher current could overheat the coil.

If it would be easy to make the globe levitate higher, the manufacturer would have done that.
 
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I don't own one of these magnetic globes btw. Its just a toy so i don't really think the manufacturer really wants to run a lot of electricity through it. It only needs to hover a centimeter or so. Its just a low powerd toy.

But i was imagining a home built version something like 10 inches in diameter. I was just curious if anyone knew how high you could possibly levitate the magnet if you if you increased the current?

The globe toy, from what i have read on the internet senses the height of the magnet somehow and adjusts the current accordingly.

Im assuming here that we won't overheat the coil.
But say i did build one and made a nice magnetic field and balanced my magnet on there but wanted to go further? higher?
But i couldn't increase the current because i would overheat the copper coil.

What could i do? instead of building a bigger coil would there be any other materials that i could use instead of copper that i could use?

Im assuming that increasing the current will give me as larger magnetic field here. I honestly am learning as i go.

Thanks
 
I'm curious how this thing works:

How will a magnetic field escape a toroid?
Is ac-current used as for the toroid?
Is the "magnet" in the globe a magnet or just a piece of metal wherein eddy-currents are induced?
If the "magnet" in the globe is repelled by the toroid, why will the hovering globe not turn upside down? ( magnet too heavy? )
 
Last edited:
Copper is the best reasonable conductor - I guess you don't want to make a coil out of silver or cool it with liquid nitrogen. The stabilization system is tricky and significantly harder than just getting something to not fall down.
In general, height will scale with the size of the base - getting a height larger than the width of the base would be really tricky.
 
Perhaps the electromagnet is not toroidal?
 
NascentOxygen said:
Perhaps the solenoid former is not toroidal?
Are you saying that it is not a toroid, but a solenoid?

And then:
Hesch said:
Is ac-current used as for the toroid solenoid?
Is the "magnet" in the globe a magnet or just a piece of metal wherein eddy-currents are induced?
If the "magnet" in the globe is repelled by the toroid solenoid, why will the hovering globe not turn upside down? ( magnet too heavy? )
 
Until a photo is posted, we can't say whether the solenoid core is toroidal or not.
 
  • #10
Here is a link anyhow of the type of levitating toy i described:



I will, after this post search the web for a teardown but please have a look at this for now.

In response to Herch i honestly don't know the answers to your questions I am afraid. It is described as a magnet in some videos but it may not be i will try and find out.

At first i just called the magnet at the base a "doughnut electromagnet" and after some goggling i came across a "toroid" which appeared, at least to me to be what i was looking for.

In response to mfb i would consider silver if it was significantly better. I in all likelihood won't but here I am just seeing how high i could really go.
 
  • #11
http://hackedgadgets.com/2010/08/30/levitating-rotating-globe/

And one more
 
  • #12
magiktcup said:
In response to mfb i would consider silver if it was significantly better.
No. Its resistance is about 5% lower, but its price is higher by a factor of 100. Copper is the best conductor for all practical purposes, unless superconductors become interesting (for things like large particle accelerators, or multi-megawatt applications elsewhere).

The globe probably uses multiple magnets in some unknown arrangement.
 

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