Tesla Would Be Proud: Wireless Charging For Electric Cars Gets Closer To Reality 176
curtwoodward writes "For some reason, we're still plugging in electric-powered devices like a bunch of savages. But technology developed at MIT could soon make that a thing of the past, at least for hybrid cars. A small Boston-area company, WiTricity, is a key part of Toyota's growing experiment with wireless charging tech---something the world's largest car maker says it will start seriously testing in the U.S., Japan and Europe next year. The system works by converting AC to a higher frequency and voltage and sending it to a receiver that resonates at the same frequency, making it possible to transfer the power safely via magnetic field. Intel and Foxconn are also investors, and you might see them license the tech soon as well."
This idea again? Nothing new, move along. (Score:3, Informative)
Gee folks, the laws of physics pretty much govern how "wireless" transmission of energy works. Using magnetic fields to transfer power from here to there is not new, we've been doing it long before Edison and Westinghouse where fighting it out over AC verses DC over 100 years ago. Westinghouse used "transformers" way back then so transferring power from one coil of wire to another though a magnetic field is not new.
But they are using a different frequency! That's new right? Not so fast... Designers have been using higher frequencies in transformers for a long time now. Aircraft have routinely used 400 Cycle power systems so designers could use smaller (and lighter) transformers since before WWII. Further, we now routinely use frequencies in the Kilohertz in switching power supplies for the same reason. More efficiency, smaller size and weight by using higher frequencies.
But they really haven't solved anything or come up with anything new. They will suffer efficiency losses because their magnetic flux coupling is weak due to the distances involved, they will suffer from limited ability to transfer power because the maximum flux density of air is pretty low, and they will have to add significant weight to the cars being charged by adding large coils of wire with many turns to them.
Nothing new to see here..
Re:This idea again? Nothing new, move along. (Score:2, Informative)
YOU aren't familiar with the difference between power transfer by way of magnetic induction, and power transfer by way of *resonant* magnetic induction, so THEY haven't done anything new. :sigh:
There's a TED Talk where the prototype-level version of this technology was demoed. It's a few years old at this stage. It doesn't require minute distances, it has lower power losses than your typical 'wall wart' AC/DC converter, and transfer efficiency doesn't drop off with the square of the range.