An article in my newspaper today, written by Lisa M. Krieger (ikrieger@ bayareanewsgroup.com), says that Stanford University is trying to develop cordless charging that might eventually be used to charge electric vehicles as they drive along the highway. Unfortunately, they have a ways to go before this dream becomes a reality. At the moment they can send a 1-milliwatt charge to a mobile LED bulb located up to three feet away.
The Stanford team has eliminated the radio-frequency source currently used in stationary cordless charging and replaced it with a commercially available voltage amplifier and feedback resistor. This system automatically figures out the right frequency for different distances. There's no need for humans to do it. "Adding the amplifier allows power to be very efficiently transferred across most of the three-foot range and despite the changing orientation of the receiving coil", according to team member Sid Assawaworrarit, a graduate student. "This eliminates the need for automatic and continuous tuning of any aspect of the circuits."
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Topic: Mobile cordless charging (Read 265 times)