Electronic Levitron...How the heck does this thing work?

[TinselKoala]

I liked the first vid with the motor,, the chopstick you were using was making it move,, I had to watch it twice just to make sure I was not just seeing things

Yes, the photoresistors and op-amp make it very sensitive, it responded even to the very thin shadow of the chopstick!

[Nink]

Wow works better than I thought it would. Nice work. I may try building one with a couple of hall switches next week (wife has me doing Christmas lights this weekend )

[TinselKoala]

Horizontal mounting:
http://www.youtube.com/watch?v=cgikT9HEiyM

Draws about 50-60 mA at +/- 13.5 V wrt 0 reference, and the little transistors I used are hot but not scorching.
(BC556B and BC337-25)

[Nink]

Horizontal mounting:
http://www.youtube.com/watch?v=cgikT9HEiyM

Draws about 50-60 mA at +/- 13.5 V wrt 0 reference, and the little transistors I used are hot but not scorching.
(BC556B and BC337-25)

Nice did you stick it on a sessaw and see if it would balance ?

[TinselKoala]

Nice did you stick it on a sessaw and see if it would balance ?

No but I'm sure it could be made to do so.

One thing that may not be obvious is that it would not work with a simple bar magnet in there. The magnets stuck onto the rod ends are oriented like this:

N:S===[[[[[coil]]]]]]===S:N

So that the  coil always attracts from one side and repels from the other side. When the coil reverses polarity, the attraction/repulsion sides swap ends.