Drivers of electric cars are quick to tell you how much they love never having to stop at a gas station.
But they still have to stop and plug in. What if you could completely cut loose electric cars to roam this great land, recharging their batteries on the fly?
That’s been a dream of automotive engineers for years, and scientists at Stanford University say it just took a leap forward in one of their labs.
Dynamic Charging Gets a Boost
“Generally speaking,” says Fan, with his gift for understatement, “I think what we have done here is really to show that you could charge a moving object efficiently.”
Wireless charging of stationary objects is already becoming ho-hum, finding uses from cell phones to shuttle buses. Ford recently rolled out a wireless system that EV owners can install in their own garages.
Charging moving objects is a lot trickier. Previous work in the United Kingdom and South Korea has used magnetic induction systems, in which a charged coil creates a magnetic field that jiggles electrons in a nearby companion coil, causing it to create its own electric current. It’s what happens when you set your electric toothbrush onto the charging base. But the technology only works over very short distances and breaks down quickly as the two coils move apart.
By adding some off-the-shelf components, Fan and Assawaworrarit have found a way to amplify the voltage and current and keep the two coils humming, even as one of them moves through the field. Their magnetic resonance approach has been called “ingenious,” and while they’ve so far demonstrated it only at very low…