This isn’t ground breaking stuff above, but it’s nice to see what a little ingenuity can produce. Created by one Chris Rieger, it’s a 3W LED light bulb that’s 1) levitating and 2) being powered completely wirelessly. Obviously… since it’s levitating. How is this done?
Levitation is managed by a permanent magnet on the light assembly and an electromagnetic coil hidden on the other side of the top panel for the enclosure. That coil uses 300 meters of 20 AWG wire. A hall effect sensor is used to provide feedback on the location of the light unit, allowing the current going to the coil to be adjusted in order to keep the light unit stationary. When working correctly this draws about 0.25A at 12V.
Wireless power transfer is facilitated by a single large hoop of wire driven with alternating current at 1 MHz. This part of the system pulls 0.5A at 12V, bringing the whole of the consumption in at around 9 Watts. Not too bad. Check out [Chris'] demo video embedded after the break.
We’re a little sad that this kind of stuff isn’t commercially available and is only ever seen as cool proof-of-concept videos online. Why? Probably because no one thinks they can make money off this. We disagree. We’d pay top dollar to have these around the office.