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Science: Radio
Radio Powered   (+3, -16)  [vote for, against]
Its Electric

Radio waves are a form of energy so why can’t we convert them to electricity?

I propose a device that can take a radio wave convert it to AC power and market this as a power supply.

Simple and effective!
-- toomer34, Jan 30 2006

rado waves http://en.wikipedia...iki/Radio_frequency
[toomer34, Jan 30 2006]

power converter http://en.wikipedia...iki/Power_converter
[toomer34, Jan 30 2006]

Tesla's Concept of Wireless Transmission of Electrical Energy to Long Distances http://www.teslasoc...om/teslabanquet.htm
Actually built towers to do this.. [xenzag, Jan 30 2006, last modified Jun 17 2009]

Radio powered cell phone! Exactly what I had posted 6 months back! http://tech.yahoo.com/blogs/null/143945
This is a lesson on how good ideas could be killed by the public! Thank you very much! [xkuntay, Jun 16 2009]

wiki Rectenna http://en.wikipedia.org/wiki/Rectenna
[knowtion, Jun 21 2009]

Infrared laser plane http://www.youtube....watch?v=wto6PEnGWrU
[knowtion, Jun 21 2009]

Ion power group http://ionpowergroup.com/
company that makes power from the atmosphere [travbm, Oct 29 2015]

Power recieving modules http://www.free-ene....co.uk/Chapter7.pdf
Power from air limited by antenna surface area. [travbm, Oct 29 2015]

google the word "rectenna"
-- lurch, Jan 30 2006


The induction that is generated by radio waves is way to low. The only reason it can be heard on your radio receiver is because it gets amplified (which again requires some extra energy).

I think Tesla experimented a lot with over-air electricity transmission, he even managed to move the boat on the lake by electricity transmitted wirelessly.
-- mrak, Jan 30 2006


y'know "rectenna" doesn't really sound like what it actually means. Sounds like a whole other HB idea, in fact.
-- PollyNo9, Jan 30 2006


If you've been around the right terminology, it makes sense. But I know what you mean. In fact, I bet many of us could even guess who would have posted it.

And what [DrCurry] would have thought it was.
-- lurch, Jan 30 2006


They had that as an experiment on the "free energy" episode of the "Mythbusters" show on the US Discovery Channel. Summary: Yes, you can get energy out of it, but it's very little - even with a really long and unwieldy antenna, you get out barely enough to drive a digital watch.
-- jutta, Jan 30 2006


[toomer34] Try to look at the specification of an ordinary FM radio - the sensitivity is usually quoted in microvolts. [-]
Remember the inverse square law.
-- coprocephalous, Jan 30 2006


//Google rectenna// Thanks [lurch], up until now i had thought a rectenna was that huge array that popped out of Cartman's arse sometimes.
-- ConsulFlaminicus, Jan 30 2006


so wat your saying is that becuse nobody could make a profit on this witch is acually very simple to fix its baked but not "Baked" ill leave it up still. to show of man's stupidity in not thinking of how to use it. two words "direct TV"
-- toomer34, Jan 30 2006


Broadcast is difficult, but beamcast is possible. Look into Solar Power Sattellites
-- Galbinus_Caeli, Jan 30 2006


When I hear the word "rectenna", I'm reminded of South Park, Episode 1. But seriously, the amount of energy picked up by an antenna is usually miniscule, needing lots of amplification before you can hear the signal.

If the beam is focused so that the majority of the energy gets to your antenna, then this works just fine (again, see "rectenna"). But without the associated focused transmission infrastructure, simply sticking out an antenna and hoping to collect enough stray radio waves to power anything more than a crystal earpiece or wristwatch is either wishful thinking or just plain bad science.

So: can power be collected from stray radio waves? Yes. Is it enough to do anything useful with? Not really. Is this a new idea? No.
-- Freefall, Jan 30 2006


well no one ever said that i got out much did they?

as i remember it this is not the only dud idea that has been baked befor and there still up i just hope this sad obomination of an idea gets off the front page befor more people see my mistake.
-- toomer34, Jan 31 2006


I thought building a radio without adding power to the circuitry was a halfbaking prerequisite, like putting cats in boxes, and shining light through holes in cardboard.
-- Shz, Jan 31 2006


[Shz] You mean like a Crystal Set?
-- hippo, Jan 31 2006


Yes.
-- Shz, Jan 31 2006


In my callow youth I made the obligatory crystal set and measured the voltage produced after rectification. We lived in a tall, thin house and I managed to use an antenna 40 feet in length. I recollect that Radio 2 medium wave (in those Mantovani days) yielded just over 50 millivolts.
-- DenholmRicshaw, Jan 31 2006


...and my callow youth is most upset...
-- DenholmRicshaw, Jan 31 2006


at least i am cosistant
-- toomer34, Feb 01 2006


Hey, I did the crystal set thing too... the aerial stretched right down the garden and it lasted until we built an extension which rather terminally blocked the signal, i.e. it was built where the aerial used to be.
-- david_scothern, Feb 01 2006


[jutta], did you or did you not mark my Radiowave Charger idea because Nokia wanted, and even worse, did you or did you not give this idea to Nokia?
-- xkuntay, Jun 17 2009


Hmmmmm, [xkuntay], maybe you delve too deep or venture too close for comfort in the realms of secret weaponry...
-- rotary, Jun 17 2009


See the Tesla link.
-- xenzag, Jun 17 2009


This can be done but as many people said, the energy will be quite low, I believe if you had an antenna about a mile long you could light an LED, but if you have a mile long antenna and just need to light an LED your in buisness.
-- Hirudinea, Jun 17 2009


[rotary] What secret weaponry, what fusion bomb? I don't know what you are talking about!

[Hirudinea] May be right, but if the cell phone could be attached to a metal structure, such as a car or bridge, it could capture more radio waves to serve its purpose, as we all know that these structures can serve as anthennas. Moreover, the cell phone could have a roll of highly conductive thin wire that could be rolled out to create a dish anthenna in case of emergency... [truncated]
-- xkuntay, Jun 21 2009


One might argue Tesla had this idea a hundred years ago and if Nokia stole it from anyone, it would most likely be him. That aside, I assumed xkuntay's talk about Nokia stealing his/her idea was tongue in cheek.
-- Veho, Jun 22 2009


I'll retract my anno if [xkuntey] confirms that.
-- WcW, Jun 22 2009


Yes it was tongue in cheek. Thanks [Veho]. But I'll still take that off if it disturbed some. Besides, I have better Big Secrets that I am keeping to myself, such as a seat belt that produces electricity while pulled. Dang! I gave that one out, but I will never mention the other ones.
-- xkuntay, Jun 22 2009


Ion power group has you beat but germanium crystal and capacitors have been put into energy harvesting boards.
-- travbm, Oct 29 2015



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