Converting radio waves

[vikster]

Hi,

i was wondering, since our world is filled with satelite and radio waves, would it be possibe to take the electricity in those waves and use it as general electricty. AC or DC. I'm a complete noob to this and got this idea when i just got a satelite a few months ago.

 

thnx

[eruheru]

i think someone had a similar idea using lightning

[vikster]

ok so if wanted to make something that would do this, how would I/ what would i need?

[ecoli]

Radio waves are just energy, and do not produce electricity. Yeah, I guess you could use the energy to excite some atoms, but it wouldn't be enough to be feasible. http://members.aol.com/nicholashl/waves/waves.htm

 

As for lightning, that is electricity, although the problem comes in how to harvest the lightning... It's too unpredictable to catch.

[YT2095]

actualy every single radio receiver does exactly this, turn the RF into AC electricity, strips of the high frequency carrier and the difference is the Audio/data

 

there Have been a few cases where some floks living close to a radio station have set up Coils in the loft/attic to capture these radio waves and convert them into usable electricity, needless to say that when they were caught, they were heavily fined too!

[swansont]

As YT implied, you'd have to be close to a transmitter to get anything usable. Satellite signals are pretty weak by the time they get to you on the ground, because they've spread out - they're typically a small fraction of a watt, and amplified in order to do anything with the transmitted information.

[vikster]

Oh ok thnx well there goes that idea of free electricity.

[Douglas]

Hmmm, I suppose if you had a 20 megawatt radar transmitter in your yard (paid for by someone else), and you had enough mu-metal around you to keep from frying your balls, you might be able to salvage some useful energy.

[DV8 2XL]

RFID The tags contain circuitry that harvest power from radio waves emitted by ambient interrogating readers, and use this power to send back a unique identifier to the reader. So its got some application.

[Lance]

It is possible to build a receiver that can power a small LED indefinitely from ambient radio waves, but needless to say an LED doesn't draw much current and beyond this it's not very useful.

[5614]

It is possible to build a receiver that can power a small LED indefinitely from ambient radio waves, but needless to say an LED doesn't draw much current and beyond this it's not very useful.

Would this just be a standard receiver with a LED output?

 

Have you got a circuit diagram?

[ecoli]

but just taking radio waves out of the atmosphere wouldn't be useful for producing electricity... which is what the question was, correct?

[Douglas]

but just taking radio waves out of the atmosphere wouldn't be useful for producing electricity... which is what the question was, correct?

Yeah Ecoli, if radio waves or any other waves could produce electricity (as we know it) we'd have perpetual motion......a little energy in, but lots of energy out.

[cchea]

Hi' date='

i was wondering, since our world is filled with satelite and radio waves, would it be possibe to take the electricity in those waves and use it as general electricty. AC or DC. I'm a complete noob to this and got this idea when i just got a satelite a few months ago.

 

thnx[/quote']

I think it is achievable, but in a very short range of distance.

[YT2095]

one of the easiest demonstrations of this is to get 2 Germanium diodes anode to cathode and join them with a long wire (your now antenta) the other ends go to a moving coil meter + to + and - to -.

now if you make a call on your cell fone you`ll see the meters needle swing right over, that`s converting the RF back into DC electricity, enough to power a meter

[cyeokpeng]

True, in the way as YT2095 has described, you can generate electricity, but the current generated in the coil (I think in pico to microAmpere range) is too small for any use in most electrical applications. Even the least power-hungry device like the LED, I doubt it will light up.

[Pleiades]

If you want to turn electromagnetic radiation into electricity, you’d be better off using visible light; just buy some solar panels. I believe there is about 1 kilowatt of solar energy falling on 1 square meter; of course, solar panels are like 12% efficient so you get more like 100 watts.