Wireless transmission of electricity

[ludi_srbin]

Is there any research done in this field? If there is why it was not realized by now? It is known that Tesla did some research on this topic but never got the funding for his Wardenclyffe Tower. I think that he managed to send electricity at about 40 miles without using any wires.

 

[Pengwuino]

I think there was a thread on this and the idea is just way too dangerous to do on a usable level.

 

[berkeman]

The closest modern application that I've seen proposed was to use microwaves to beam energy down to Earth from orbiting solar panel farms. But there's the pesky problem of toasting everything in the beam, including birds, airplanes, etc. You can transmit power as EM waves, but when you get to useful power transfer levels, the beam is very dangerous.

 

[Shawnzyoo]

crystal radio

i know if you use a crystal radio close enough to the AM transmitter it doesn't require any usage of external power
how does that work?

 

[berkeman]

i know if you use a crystal radio close enough to the AM transmitter it doesn't require any usage of external power
how does that work?

I had a crystal radio as a kid. I think I got one station pretty reliably, and sometimes hints of other stations. The metal whisker and the crystal form a rectifying diode, so if you have a reasonably resonant long-wire antenna, you can get enough of an AC voltage to power a very low power earpiece. A quarter-wave is about 75m at 1MHz, so it takes a good long wire suspended above the ground perpendicular to the line-of-sight to the transmitter to have a chance of picking up a good voltage. Man, that takes me back (to the stone age almost... :-)

 

[dlgoff]

Man, that takes me back (to the stone age almost... :-)

Me too. I was just thinking the other day about selenium rectifiers. Remember those plates?

Regards

 

[Random]

Check the Tesla web ring for details on Tesla. Not that there was no money for the project - just that there was no way of metering any usage, so no way to charge for it - so what commercial enterprise would back that? More recent attempts to replicate the work have been made by a few groups - with varying results. Teslas scheme was far bigger and more 'global'than people either then (or now) would finance. Additional problems would be occasioned now by modern electronics being so sensitive to static. Tesla was charging the Earth as one plate of a giant capacitor - with the upper atmosphere for the other plate. Transmission along these lines certainly works. My own humble attempt saw sparks being able to be drawn from the water mains for a few blocks around me.. It bugged the hell out of everyone with flouro tubes for house lighting.. they glowed constantly. Not impossible, just politically and economically devisive. Sad really. :|

 

[ludi_srbin]

How exactly did you do it? Do you need to be very good (Engineer) or is it possible for an amateur like me?

 

[Random]

As I say, check the coil builders sites for coil design info. Teslas Colorado Springs Notes is a good (but heavy going) read. Basically, a spark discharge means a 'failure'. Set things for primary resonance and "St. Elmo's Fire"or 'secondary efflueve' as it is sometimes called. Pump the input power up to about 7KVA and you'll be doing it too.

 

[Antiphon]

In addition to the safety factors mentioned above, wireless
transmission of power is not as efficient as wired transmission. When you
sell product by the kilowatt, you lose money to the water vapor and passing birds.

 

[young e.]

i think there's somebody out there trying to make an attempt on that matter. but its to dabgerous and the operation is not efficient when transmitting large amount of electric energy unwired.

 

[nikola-tesla]

Only Tesla could do it.

 

[Antiphon]

Only Tesla could do it.

I'm not taking anything away from the Genius Tesla. But
Wardenclyffe was a failure in my engineering judgement.

 

[FreeEnergy]

What about the reverse??

I've read a fair amount about Tesla and radio waves. I've never tried to measure electricity in an antenna but if you were to setup a large enough antenna would you be able to collect a current in the antenna? If so, could you not collect the electricity in a battery from the wire?