When will we see small scale wireless power? (Like a wireless phone charger.)?

Question

Think of it in terms of transformer. They transfer voltage through a magnetic field. Is there any research being done on how to control this directionally? Or should I have contacted a patent office instead of Yahoo answers.

Answer 1

At some level, people are still experimenting with it. For example radio frequency identification tags (RFID) are esstentially powered by local bursts of RF power (see Reference 1). There also are some vendors offering low-power, very local wireless power solutions (see Reference 2). Of course, NASA is thinking about some serious wireless power (see Reference 3)

Answer 2

It is already used for some devices. For instance, my rechargeable toothbrush charges by induction with its base. the principles have been known a long time, and predate Tesla.

However, there is a problem with transferring large amounts of power and that is that the high fields involved would be dangerous and would interfere with electrical equipment.

The way round this is resonance - transmit a very low power field but have it resonate with just the recieving device. This way the risk to non resonating bodies (like yours or mine) is low.

There is indeed research on this at the moment to give some form of wireless power.

Answer 3

nikolas tesla claimed to be able to do it in the 1890s. however it has never panned out to anything.
http://www.tfcbooks.com/articles/tws8c.htm
I've not heard of any serious research except for close proximity transfer. for example sometimes when an electronic system is gimbal mounted and the force exerted by mechanically connected wires is significant, they transmit power through the mounts.

Answer 4

Do you really want it? You're already afraid of cancer from cellphones. Broadcast energy sources will require much higher concentrations of radiation that will make it unsafe for anyone to be pregnant.

Answer 5

It is being done. It just seldom has enough advantage over simpler alternatives. Many cordless toothbrushes charge this way.