Re: Soljacic wins $10k MIT Young Scholar Award (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 01 Sep 2007 13:33:58 -0700
From: Jim Lux <jimlux@xxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Soljacic wins $10k MIT Young Scholar Award (fwd)

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Sat, 01 Sep 2007 13:45:37 -0300
> From: Antonio Carlos M. de Queiroz <acmdq@xxxxxxxxxx>

> I am making some experiments with a system using grounded transmitter 
> and receiver, that easily
> transmits 0.25-0.5 of the input power to a few meters away. Curious 
> demonstration, but the amount
> of wire used is much greater than the necessary to transport the power 
> directly...

I never thought about that aspect of it (I was more thinking of the 
impracticality of such a large near field vis a vis safety)

You're right.  That meter diameter coil with 10 turns of heavy copper 
wire or tubing (e.g. 30+ meters of copper tubing), as opposed to 1 meter 
of small gauge copper to carry the power directly.

Inductive power transfer has been used for decades, even on an 
industrial scale: supplying excitation current to the rotor of a 
synchronous generator, for example.  It's also used instead of slip 
rings to get power to a moving platform on spacecraft.  And, of course 
the example of the wireless recharging of the electric toothbrush 
mentioned in the articles.