

Wireless Charging, at a Distance, Moves Forward for uBeam - antoinec
http://bits.blogs.nytimes.com/2014/08/06/ubeam-technology-will-enable-people-to-charge-devices-through-the-air/?_php=true&_type=blogs&_r=2&&utm_content=bufferdf3d4&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

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sssilver
> "her career goal was to eventually find life on other planets. Instead, Ms.
> Perry accidentally stumbled upon something even more exciting: the ability
> to charge portable electronics, like cellphones and laptops, wirelessly
> using ultrasound"

What's wrong with you people, how's charging portable electronics more
exciting than finding life on another planet??

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omonra
With age people start to consider opportunities from the Expected Value
perspective.

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trsohmers
If people just understood the inverse square law and other related functions,
stuff like this wouldn't be thought of as so revolutionary. While I do see
some potential for this technology as a product for those that do not care
about their home electricity bill, would you really want to have less than 1%
efficiency? Think of it this way: You are using electricity to generate
oscillating waves in the air, directing that to a receiver, which is then
turning that back in to electricity. This has some promise for extremely low
power devices (think milliwatts), would you want to have a 500W power supply
to charge a 5W phone?

References:
[https://workspace.imperial.ac.uk/opticalandsemidev/Public/Pu...](https://workspace.imperial.ac.uk/opticalandsemidev/Public/Publications/Ultrasonic%20vs.%20Inductive.pdf)
(39% efficency at 1mm, 0.013% at 10cm)

The best that I've seen (promising for IoT...) "The authors showed that with
these transducers data communications can be achieved at wall-transducer
standoff distances of up to 10 mm. Of the many tested configurations, the
authors quote the performance of a 400 mW Tx system operating across a 25 mm
steel wall. This system achieved a 10 mW power transmission (0.25% efficiency)
and a 1 Mb/s data transmission rate. The authors expect that the power
transmission efficiency can be increased to 1%."
[http://iopscience.iop.org/1742-6596/305/1/012088/pdf/1742-65...](http://iopscience.iop.org/1742-6596/305/1/012088/pdf/1742-6596_305_1_012088.pdf)

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mmastrac
Directional transmission isn't subject to the inverse-square law (well, sort
of [1][2]), only omni-directional transmission. While I don't know much about
uBeam, there are efforts to use beam-forming to make charging more efficient,
ie:

[http://www.scribd.com/doc/70793467/Wireless-
Charging](http://www.scribd.com/doc/70793467/Wireless-Charging)

[1]
[http://www.physicsforums.com/showthread.php?t=633345](http://www.physicsforums.com/showthread.php?t=633345)
[2]
[http://www.physicsforums.com/showthread.php?t=177187](http://www.physicsforums.com/showthread.php?t=177187)

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Nux
Very interesting, might just work.

They need to be careful with the frequencies though, not to screw around with
the wildlife and pets around us.

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vonklaus
In the TED talk it is explained as safe. Just light electromagnetic waves.

[http://www.ted.com/talks/eric_giler_demos_wireless_electrici...](http://www.ted.com/talks/eric_giler_demos_wireless_electricity)

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vonklaus
This is going to be major. This space is progressing and is going to be
similar to the television revolution our parents lived through. We are on
early black and white right now, but this is going to be so ubiquitous for
most things our kids will laugh at wires like we do at black and white.

