新型无线电源技术

So, we're finally going to cut the cord, say goodbye to that massive cables pouring from your desk that, one annoying wire coming from your speakers. Power is going wireless. The concept has been around for over a century.

Nicola Tesler came up with it shortly after he discovered alternating current, or AC. AC is a flow of electrons through a conductor that alternates back and forth. Teslen knew that when you alternate a current, you create a magnetic field. Conversely, if you oscillate a magnetic field and move a wire into it. That wire would conduct AC. Wireless electricity works in this way. The transmitter converses AC into a magnetic field, the device picks up the field and converses it back to AC. Sounds fairly simple, but there's reason it took over a century to become viable.

The sticking point has been something called magnetic resonance energy transfer. Without this phenomenon, wireless electricity won't transmit far enough to be usefull. This is how it works.

All magnetic fields vibrate at a resonant frequency. If two nearby fields have the same resonant frequency, they transfer energy very efficiently over long distances. This is how an opera singer, for example, can shatter a glass with just her voice. In wireless electricity, the transmitter and device are viberating at the same resonant frequency. This was not an easy task for Teslor, although in 1899, he powered two hundred light bulbs from 26 miles away. Modern advances have made this much easier, and now wireless electricity is about to hit the market in a big way. Just imagine transmitters that look like picture frames providing power to lights and laptops. A phone charger that starts charging your phone right when you sit down on your desk. The possibilitie really are jolting.