HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
<<  <  Page 9/9
Tcrook
User Rank
Gold
Re: Cool, but it's stealing
Tcrook   3/20/2013 2:20:03 PM
NO RATINGS
Doesn't anyone here remember 'crystal radios'?  The only thing novel here is the use of this stray energy to charge a battery instead of driving the earphones.

bob from maine
User Rank
Platinum
Re: Cool, but it's stealing
bob from maine   3/20/2013 1:53:48 PM
TANSTAAFL - Thair Ain't No Such Thing As A Free Lunch. A single wire transporting electrical energy which emits an electric field represents a certain parasitic load. When you run another single wire or device that couples the electric field of the first wire, you increase the load. Not unlike a transformer, thus as secondary current increases, primary current does as well. Wires that are designed to emit radiation (antenna's) emit the electrical energy as RF radiation and it can be harvested without diminishing the source, however the available current is miniscule. Charging a small battery in a day from radiated sources is pretty inefficient considering the wide range of other available energy sources.

Ann R. Thryft
User Rank
Blogger
Re: Cool, but it's stealing
Ann R. Thryft   3/20/2013 1:32:38 PM
I agree with Elizabeth: stealing implies that the thief takes away something so there's less of it. That's not at all the case here: this is harvesting secondary energy from a source which is primarily providing the primary energy. It's not like someone's house on the power line has less electricity available, or even that the power station at the source of the line has less energy available. This is using "waste" energy that's been previously unused. There's a lot of "waste" energy in the world created by various sources.

Elizabeth M
User Rank
Blogger
Re: Cool, but it's stealing
Elizabeth M   3/20/2013 12:30:56 PM
Well, I suppose you could look at it that way, dka, kind of like copying someone's CD MP3 collection. But I think that it's more using energy that already exists rather than stealing. And I'm pretty sure it's using the electricity that the wires themselves are emitting...I suppose they come from the power company originally, but at that point a case could be made that it is coming from the wires and perhaps even have its own existence, as it is now a part of the air. But I do see what you're saying!

dka
User Rank
Bronze
Cool, but it's stealing
dka   3/20/2013 12:23:28 PM
Back in electromagnetic theory class we discussed the idea of building a car that could operate near power lines to do the same thing this kid is doing.  There are power lines running alongside most roads anyway.  The antenna would probably be unpractically large, and would have to be unpractically close to the wires to get enough power, but it's probably sorta doable.  Either way, it's stealing because the energy coupled into the device only comes from the power company.

<<  <  Page 9/9


Partner Zone
Latest Analysis
Advertised as the "Most Powerful Tablet Under $100," the Kindle Fire HD 6 was too tempting for the team at iFixit to pass up. Join us to find out if inexpensive means cheap, irreparable, or just down right economical. It's teardown time!
The first photos made with a 3D-printed telescope are here and they're not as fuzzy as you might expect. A team from the University of Sheffield beat NASA to the goal. The photos of the Moon were made with a reflecting telescope that cost the research team 100 to make (about $161 US).
At Medical Design & Manufacturing Midwest, Joe Wascow told Design News how Optimal Design prototyped a machine that captures the wing-beat of a duck.
The increased adoption of wireless technology for mission-critical applications has revved up the global market for dynamic electronic general purpose (GP) test equipment. As the link between cloud networks and devices -- smartphones, tablets, and notebooks -- results in more complex devices under test, the demand for radio frequency test equipment is starting to intensify.
Much of the research on lithium-ion batteries is focused on how to make the batteries charge more quickly and last longer than they currently do, work that would significantly improve the experience of mobile device users, as well EV and hybrid car drivers. Researchers in Singapore have come up with what seems like the best solution so far -- a battery that can recharge itself in mere minutes and has a potential lifespan of 20 years.
More:Blogs|News
Design News Webinar Series
10/7/2014 8:00 a.m. California / 11:00 a.m. New York
9/25/2014 11:00 a.m. California / 2:00 p.m. New York
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Oct 20 - 24, How to Design & Build an Embedded Web Server: An Embedded TCP/IP Tutorial
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: 10/28-10/30 11:00 AM
Sponsored by Stratasys
Next Class: 10/28-10/30 2:00 PM
Sponsored by Gates Corporation
Next Class: 11/11-11/13 2:00 PM
Sponsored by Littelfuse
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service