Within three years, according to Back To The Future Pt. II, we should have flying cars and hoverboards. We’ve got a lot of work to do before that becomes a reality, but designer Chris Rieger has been working on something that could be levitating in our lives in the near future — lights! Rieger is developing a levitating lamp that could eliminate the need for wires.
Reiger’s LevLight project uses wireless power and magnets to create floating lights, which, in theory, could be used to light up an entire house. The lights float thanks to a magnet on the light assembly and an electromagnetic coil hidden on the other side of the top panel for the enclosure. The design is hardly as simple as it sound.
“Stable levitation is not easy,” Reiger explains. “Instead of boring you with the failed attempts, instead I’ll tell you what worked. For the levitation system I ended up slightly modifying an existing circuit built by Eric Taylor. My configuration is slightly different and am using a 3 pin linear hall effect sensor from RS components to act as the feedback mechanism.”
“I opted for a 1.325mV/g sensor (the smallest sensitivity I could find), as the magnetic flux it was sensing was maxing out the reading on others. If you are looking to build one, this circuit is simple and works with only slight modification depending on the input sensor you have. The drive coil I’m using is 300 metres (1kg) of 20awg wire. It draws about 0.2 – 0.25A when stable at 12V. It doesn’t seem to heat up over time, unless the light is not levitating, in which maximum (0.8A) current is driven through the coil.”
But it was the LevLight’s wireless design that proved to be the most problematic. “I started off with 555 oscillators used by a few people,” said Reiger. “(But) the power transfer is not strong enough and the waveform was horrendous.” Instead the power 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.
I think you’ll agree that is quite an accomplishment and hopefully we’ll see them on shelves soon. Although if a certain components shorts out, does that mean our lights would be falling on our heads?!
Images: Chris Rieger