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10 Things to Know About Wireless Power

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The hype cycle around wireless power has been gathering a charge ever since Intel (s intc) wowed folks at its IDF conference last year with a demo of wireless charging. Then over the summer, a TED video surfaced with a similar demo, starring the CEO of WiTricity. And this week we saw Dell (s dell) launch a notebook with wireless charging and Nokia (s NOK) join a new industry consortium dedicated to wireless power. But like other aspects of the wireless world, there are a lot of differences, issues and things that average outlet-avoiding consumer needs to know. Here they are:

1. Wireless power is an old idea (Tesla demoed it in 1891), but there are currently two camps trying to use magnetic induction to charge things, one offering a charging pad, and the other trying for over-the-air power.

2. The Wireless Power Consortium, an industry group formed to create standards around wireless power, argues that a charging pad is the only way to charge things efficiently. Members of the Wireless Power Consortium so far include Texas Instruments, Nokia, (which joined this week), Phillips, Samsung and Duracell.

3. The first WPC standard specification, called Qi, was released in August.

4. The goal is to use two magnetic coils, with one inside a charging pad and one (which can be added to devices for less than $1) inside a gadget that allow it to charge while sitting on the pad.

5. Efficiency rates range from 50 to 70 percent using this method, and can transfer 5 watts of power, according to Menno Treffers, chairman of the Wireless Power Consortium, and Dell, which says its laptop is 70 percent efficient.

6. A popular use of wireless power may be sitting in your bathroom. Phillips Sonicare toothbrush uses magnetic induction to charge the toothbrush. Yes, you still have to plug in the base charger.

7. Treffers expects wireless power to be in consumer devices like phones by 2011.

8. However, there’s another effort to make wireless power even sexier. Intel and WiTricity are trying to use magnetic induction to charge devices over the air. It’s pretty sweet, but so far efficiency is governed by how large the magnetic coils are and by how far apart they are from the device that needs power. The demos are using really big magnets or ones close together, and aren’t offering a lot of charging efficiency.

9. Plus, some people are worried about the effects of all that electromagnetic radiation flowing through the air.

10. So in the short term, charging pads and compatible devices are the closest we’re going to get to wireless power, unless we want to attach solar panels to our phones. But then we’re looking at a pretty long time to charge a device.

17 Responses to “10 Things to Know About Wireless Power”

  1. A single phase 2kW (delivered on the vehicle) IPT system was built early this year and demonstrated in May at the Electric Vehicle Symposium in Norway, and again in June at the first German Electric Vehicle Conference. The gap between the charging pad and underside of the car was greater than 200mm.

    The system was developed by the Power Electronics Group at the University of Auckland in New Zealand and the many patents awarded over the last few decades are held by UniServices Ltd from which licenses are available …….

  2. Inductive charging is a great idea for things that are used only two or three times a day and are exposed to water – as in my Braun electric toothbrush. I don’t believe it will be that useful for cellphones considering the electromagnetic coils that are needed. BTW – this phenomenon was discovered by Michael Faraday in 1831, before Tesla was born (in 1856).

    • Wolfkeeper

      Actually, the key part of the technology is the resonance, and that definitely was discovered by Tesla- his 1902 Tesla coil uses this to transfer the power from the bottom coil to the high voltage upper coil to avoid having wires and the attendant arcing even at very high voltages.

      Without resonance, you just have a transformer with a range of millimetres and horrible efficiency and power transfer capability, which is what Faraday probably did do in 1831.

      • I would still have to give Faraday the credit, he did the underlying ground work and was the first scientist to publish the induction phenomenon. Tesla did do great work in inductive energy, but typically the fame lies with the founder. One wouldn’t give Einstein credit as a founder of the laws of motion and gravity when all he did was correct Newton’s equations to incorporate relativity, but he certainly advanced the science much like Tesla did with Faraday’s work. ;-)

      • Faraday discovered electromagnetic induction. Wireless power over a considerable distance can’t be accomplished by electromagnetic induction.

        Tesla discovered resonant induction, a concept more like radio transmission than electro induction.

        So you might say… Marconi founded the basic princible of “long” distance power transmission. But oh! Wait! Marconi reverse engineered Tesla’s work, then claimed radio transmission as his own.

        Ahhh hell, nevermind. Al Gore probably founded both fields.

  3. I love how all of these old ideas are coming back strong today. Fuel cells are another example of technology invented in the 1800’s making a come back today.

    • Most of it comes down to one thing: Cost efficiency.
      Better materials, better manufacturing.

      I bet if we found a planet made entirely out of platinum, we’d have a nice space program going already.