Potentially revolutionary idea concerning remote power?

I learned in physics some time back that directing radio waves towards a metal object will induce an alternating current.
My question is: Could you power something with an external but unconnected power source? I'm thinking something like a guitar with no lead that still manages to send back sound data to the amp.

NB If this idea already exists, please tell me.

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the easy answer is YES, you can do it but because you cant direct and focus it you would get a expediently small amount of power than what you are emitting.
ajleece7 years ago
That idea runs off batteries.
framistan7 years ago
Nikola Tesla claimed to have accomplished the transmission of AC power without wires. The story goes that nobody would finance his idea because anyone could get free power by just putting up an antenna and a ground wire... and a tuned tesla coil to that frequency. If it doesn't make MONEY, what good is it??? The tesla coil is an air-core transformer. you can find a lot of information on him by looking up "tesla" on google.
orksecurity7 years ago
The problem is that inverse-square-law makes transferring any significant amount of power difficult. Over short distances, for very small amounts of power, sure; that's how RFID tags power themselves. Over greater distances and/or for enough power to do something nontrivial, the answer is pretty much "no" -- you need to carry a battery or other power source.

Basically: If it was that easy, it would have been done long ago.

This is why the recent MIT breakthrough involving tuned resonant coils is such a breakthrough; it's the first time someone has shown a device which can transfer a significant amount of power a signficant distance. Though that's inductive -- magnetic -- rather than radio per se.

.  +1
.  For the specified application, beaming enough RF energy to power an electric guitar is apt to harm the player's body.
lemonie7 years ago
For a guitar- connect it to a wireless microphone.

L
kelseymh7 years ago
Yes, it already exists, and there have been discussions of it here on Instructables. Look for "wireless power" in an Instructables Search.
Isn't that what wireless remotes or phones do?
The Jamalam (author)  TwistedParadox7 years ago
No, they transfer data but they still need batteries. I'm talking about inducing an actual current/voltage in something without a battery attached to the device.
That's exactly how radio and tv transmission works. But it takes a lot of power and what get at the receiver is a very tiny bit of power.

An air core transformer works this way but the distance between the sender and the receiver is very small to little power is lost.

Any receiver picking up the unmodified signal from an electric guitar would also be picking up the flor. lights, the transformers in the room, they guy welding down the street most of the radio stations in the county all of the electric motors in town etc.