How does this hoverboard work?

[Khashishi]

https://www.kickstarter.com/projects/142464853/hendo-hoverboards-worlds-first-real-hoverboard

I see that it says it's based on Lenz's law, which says that the induced currents will generate a field that opposes the change in the field. So, I figure they have some kind of oscillating magnetic field coils on the bottom of the board, which generates an oscillating field which generates eddy currents in the non-ferromagnetic floor, which generates an opposing field that lifts the board.

But, I don't see how the floor's field can always oppose the field from the board. If the board's coils are oscillating, wouldn't the fields attract each other 50% of the time? What's going on here? Is there some kind of trick so the changing field can always have the same sign?

 

[NascentOxygen]

The field in the copper floor oscillates along with the current in the board's electromagnets, so they are always in opposition.

 

[sophiecentaur]

Battery capacity? it would need to be pretty large - unless there are a lot of cuts in that movie.

 

[zoki85]

Nice, but surface/floor below the board got to be very conductive

 

[rohn]

Engine uses electromagnets that produce changing magnetic fields to interact with a conducting surface. Basically when these electromagnets change the magnetic field that produces an electric current in the metallic surface underneath the hoverboard. This electric current then produces its own magnetic field to repel the hoverboard electromagnets.
The Only problem with this hoverboard is that it only hovers over a conducting surface. So it requires the conducting surface.

 

[hsdrop]

Would other metals work other than copper (that's a little to price for me) like tin, sheet steel, and or iron?
Also does anyone have a rough guess on how thick the metal would be for it to work?

Would the magnetic fields generate a current in the metal plating on the floor or is there one?

 

[Jonathan Scott]

Their website says it requires a non-ferromagnetic metal. I assume the metal surface is completely passive.

From past experience with electromagnetic levitation at school (over 40 years ago), I think it probably requires that the metal is a good conductor both of electricity and heat, as the induced currents will otherwise create hot spots. (We used to fry an egg on a levitated frying pan, both because it was amusing and because it helped to absorb some of the heat; if we left the pan there too long it would start to glow red hot).