Hacked Gadgets Forum

December 5, 2008

Magnetic Levitation Light Bulb uses Wireless Energy Transfer

at 3:18 pm. Filed under Complex Hacks, Cool Gadgets, Crazy Hacks, Electronic Hacks


Robin Massink from the Netherlands has built a cool Magnetic Levitation Light Bulb it uses Wireless Energy Transfer to power the bulb. It is always weird to see something being powered with no wires!

"I used this globe (http://www.thinkgeek.com/geektoys/science/98b8/) for the levitating part. It consists of 2 permanent magnets, and 2 electromagnets, coupled with a hall sensor to keep a third magnet (inside the globe) floating. I mounted a ordinary 20W lightbulb on this magnet, after removing the plastic globe. The light bulb is connected in parallel with a 100nF capacitor, and a coil of about 40 turns of copper wire.(diameter is about 6 cm). The base has the same coil, with the 100nF capacitor in series connected. The base-coil receives a 50volt, 30kHz square wave signal, from a half H bridge(something like this: http://lh4.ggpht.com/otp.arun/SJkzTSR90lI/AAAAAAAAAh8/fqNPHXqXa8U/s400/hbri1.JPG), with the coil/capacitor connected where the motor is drawn. The current is about 0.5 amps. It works by driving the primary LC combination at resonance. A induction current is generated in the secondary coil because of the resulting magnetic field generated. The current is then directly fed into the light bulb."