Re: Electric from radio??


"sensible" <flantoons@xxxxxxxxxxxxxx> wrote in message news:ea020fe5-f59a-4831-b0c7-d876be7ef945@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Can anyone tell me whether you can get electricity from received radio
waves, please?
See this video...it has an antenna attached to a circuit of capacitors
and other stuff, and gets out volts from the other end....Does this
work? And if so, how does it work?

Thanks.

http://www.metacafe.com/watch/915226/free_electricity_from_thin_air/

I asked that question "how does it work" when I was 11 years old, and built my first 'crystal radio'.

An antenna (long copper wire), a coil, a variable capacitor, a diode and an earphone. Let's you listen to AM radio stations at long
as they transmit. No batteries required.
The earphone works directly off the energy picked up from the antenna.

For me, at 11, it was pure magic to hear a voice out of thin air. I was blown away, and for me it was the start of a long career in
electronics for me.

So how does it work ? It's a magical world of Electro Magnetic Radiation. Radio waves, light, X-rays are all EM radiation at
different frequencies. By definition, it travels at the speed of light, and it carries energy in quanta (little packets). Nobody
knows exactly what it is, but the 'wave' part it is modeled precisely in the Maxwell equations, and the 'quanta'/'wave' duality is
modeled precisely in Quantum Electro Dynamics (QED).

Rob


.

Relevant Pages

  • Re: Simple but Fundamental Antenna Question
    ... > circuits as consisting of lumped components (resistors, capacitors, ... antennas and free traveling waves have ... A whip antenna may be visualized from ... > available to soak up magnetic and electric fields from the next part ...
    (sci.electronics.basics)
  • Re: Simple but Fundamental Antenna Question
    ... circuits as consisting of lumped components (resistors, capacitors, ... antennas and free traveling waves have ... A whip antenna may be visualized from ... available to soak up magnetic and electric fields from the next part ...
    (sci.electronics.basics)
  • Electric from radio??
    ... waves, please? ... See this video...it has an antenna attached to a circuit of capacitors ...
    (rec.arts.sf.science)
  • Electric from radio??
    ... waves, please? ... See this video...it has an antenna attached to a circuit of capacitors ...
    (sci.energy)
  • Re: Old antenna for new tv
    ... about the waves cancelling each other ... How does the energy collected by the directors get to the ... but it probably has an amplifier. ... strong signal from the antenna, than a weak signal that is amplified. ...
    (alt.home.repair)