Wireless power transfer

[Hl.house]

Anyone has any experience with it? I am considering getting some sockets for charging phones, laptops, bed side lamps(occasional reading). Any pros and cons? Good/not so good brands?

 

[JohnW2]

For what it's worth, the concept sounds rather like a joke to me (at least, with present-day technology).

Kind Regards, John

 

[big-all]

i would want to know how efficient they are before even considering one
i suspect they may be far less efficient than a plug in connection but simply dont know

 

[endecotp]

I have no personal experience of the technology.
Apparently the efficiency can be greater than 50%:
http://www.batterypoweronline.com/conferences/wp-content/uploads/2015/08/WirelessConsortium.pdf

 

[stillp]

Works well for charging electric vehicles!

 

[JohnW2]

Apparently the efficiency can be greater than 50%:

That doesn't surprise me in relation to 'close-coupled' inductive power transfer - after all, that's just like a conventional transformer, without a core and with a bit more distance between primary and secondary coils. Such technology has been used for decades, in all sorts of fields, and I can believe that, in some situations, it can be 'quite efficient'.

I'm far less sure about "loosely coupled wireless (RF) power transfer" and am rather amazed that the efficiency can be anything like 40%, unless transmitter and receiver are exceptionally close and the transmitting antenna is highly directional (and pointed at the receiver!).

Kind Regards, John

 

[Naz1977]

It is a new tech. Used mainly for mobile phone charging at the moment. Give it another 5 yrs, it will be widely available for commercial/domestic use to power other things.

The transmitter at the moment to power anything hefty will be far too big and inefficient.

Concept is good though thanks to WiTricity at MIT.

 

[JohnW2]

Works well for charging electric vehicles!

... but, as I've just written, I imagine that is inductive coupling, not 'wireless'.

Kind Regards, John

 

[JohnW2]

It is a new tech. Used mainly for mobile phone charging at the moment.

As I've just written, as with cars that's really inductive coupling (a technology that has been used for years), rather than 'wireless'.

Can a mobile phone currently be charged successfully if it is, say, a few feet away from whatever is 'transmitting' the power (rather than 'sitting on top of it!)?

Kind Regards, John

 

[Brigade77]

I've always thought that anyone who 'understands' electrickery should be burnt at the stake.

Yet I've always been fascinated by the life & work of Nikola Tesla.

https://en.wikipedia.org/wiki/Wardenclyffe_Tower

 

[big-all]

for low cost charging like a mobile phone thats probably 0.25p rather than 0.1p
but a powertool could be 2.5p rather than 1p not a lot i grant you but a retro step for little convenence that i can see