lighting an led using mobile phone radiation.

when i went to science fair, i happened to c a simple circuit with an led. they brought a cell phone near to the circuit.. when we call or send msg to that mobile phone, the led started to glow. can anyone help me in building such a circuit? a simple one is enough..
thanx in advance.

Casdi5 months ago

Is this what you are looking for? Mobile Phone Signal Flash Light Radiation Power DIY https://www.behance.net/gallery/22011807/Mobile-Phone-Signal-Flash-Light-Radiation-Power-DIY-kit

I am going to guess that this is some kind of rectifier circuit,  built from some arrangement of diodes and capacitors. 

Probably the most simple rectifier circuit is just a half-wave rectifier, and the next most simple is a full-wave one.  Both of these are described in this Wikipedia article:
http://en.wikipedia.org/wiki/Rectifier

More complicated than the half-wave and full-wave, are voltage multiplier type rectifier circuits:  doublers, triplers, etc, and you can read about those here:
http://en.wikipedia.org/wiki/Voltage_multiplier

Also worth mentioning is the Tate Ambient Power circuit, because that's sort of a popular one with the "free energy" enthusiasts.  It was originally published by Joseph Tate, in USP4628299 (1986) It was intended for measuring the power output of nearby radio stations, for the purpose of predicting earthquakes (It was something to do with changes in earth conductivity.), and you can read more about that, including the circuit diagram, here:
http://www.rexresearch.com/tate/tate.htm

BTW, the next time you see a simple circuit in the wild, do not hesitate to take a picture of it, or make a diagram.  That way there is less guess-work later.
Kiteman5 years ago
You can buy them as phone charms.

For example, click here.