[LINK] Some shocking news about wireless electricity

[Stewart Fist]

Stephen wrote:
> 
> There are three basic technologies for wireless charging: radio,
> resonance, and induction.
> 
> Radio charging is well suited for charging low-power devices at long
> distances -- some 30 feet away. This technology is ideal for trickle-
> charging advance RFID chips affixed to, say, palettes loaded with
> products in a warehouse.
> 
> Resonance charging makes sense for robots, cars, vacuum cleaners, and
> other applications that require massive power over minute distances --
> essentially making contact with plastic, but not metal.
> 
> Toothbrushes now, and random gadgets will very soon, use inductive
> charging. This technology uses a coil to create an electromagnetic field
> across a charging station surface. The device then converts power from
> the field back into usable electricity, which is put to work charging the
> battery. 


I don't agree with the distinction between resonance and induction.

Who invented this distinction?

Both are induced in the near-field and therefore both are inductance
coupled.  The term resonanace, just means the coupling is matched and close,
and therefore efficient.

They'd be better off talking about 'efficient induction coupling' and
'inefficient induction coupling'


-- 
Stewart Fist, writer, journalist, film-maker
70 Middle Harbour Road, LINDFIELD, 2070, NSW, Australia
Ph +61 (2) 9416 7458