WiTricity

http://en.wikipedia.org/wiki/WiTricity

WiTricity, a portmanteau for "wireless electricity" [refers to] devices and processes which use a form of wireless energy transfer, the ability to provide electrical energy to remote objects without wires using oscillating magnetic fields.

This sounds like such a potential shift in how we conceive of electronics in general. So why hasn't this developed faster? The article mentions "well-known physical laws", but can someone be more specific?

Originally posted by Palynka
http://en.wikipedia.org/wiki/WiTricity

WiTricity, a portmanteau for "wireless electricity" [refers to] devices and processes which use a form of wireless energy transfer, the ability to provide electrical energy to remote objects without wires using oscillating magnetic fields.

This sounds like such a potential shift in how we conceive of electr ...[text shortened]... faster? The article mentions "well-known physical laws", but can someone be more specific?

Nikola Tesla (1856–1943) was experimenting with wireless energy distribution according to Wikipedia.

"... the Tesla effect of wireless energy transfer to wirelessly power electronic devices which Tesla demonstrated on a low scale with incandescent light bulbs) as early as 1893 and aspired to use for the intercontinental transmission of industrial power levels in his unfinished Wardenclyffe Tower project."

Nothing new.

Originally posted by FabianFnas
Nikola Tesla (1856–1943) was experimenting with wireless energy distribution according to Wikipedia.

"... the Tesla effect of wireless energy transfer to wirelessly power electronic devices which Tesla demonstrated on a low scale with incandescent light bulbs) as early as 1893 and aspired to use for the intercontinental transmission of industrial power levels in his unfinished Wardenclyffe Tower project."

Nothing new.

Tesla's idea was doomed from the start. The problem being the inverse square law inherent in the transfer of electrical energy in the form of radio waves of any wavelength. So if you transfer, say 50% of your power to a spot 10 feet away, then going 20 feet away, twice as far, you lose that number, in this case 2, squared so 20 feet away you are down to 1/4th of what you had at ten feet so suppose you started with 100 watts and you got 50 watts transferred at 10 feet away then move the receiver to 20 feet you now get not 25 watts but 12 1/2 watts and so forth.

What is new is the development of lightweight resonant circuitry where the transmission end is at (total guess here) at say 100 kilohertz and the receiver is also a tuned circuit at the same frequency of 100 Khz, then what is known as near field conditions allow a pretty high % of energy transfer.

It still suffers from the old inverse square law but for close distances, only a few feet or a couple of meters, it can transfer small amounts of power, enough for a cell phone or laptop but don't expect to be running your air conditioner on such a system, you would just be flooding the area with a huge RF field for nothing. Maybe it would help heat the house🙂 But I would not want to live 24/7 in such an environment.

Originally posted by FabianFnas
Nothing new.

Yes, that's what I said. Thanks for the repetition.

Originally posted by sonhouse
Tesla's idea was doomed from the start. The problem being the inverse square law inherent in the transfer of electrical energy in the form of radio waves of any wavelength. So if you transfer, say 50% of your power to a spot 10 feet away, then going 20 feet away, twice as far, you lose that number, in this case 2, squared so 20 feet away you are down to 1 ...[text shortened]... Maybe it would help heat the house🙂 But I would not want to live 24/7 in such an environment.

Thanks, sonhouse, that's exactly what I was looking for with my question.

Originally posted by Palynka
http://en.wikipedia.org/wiki/WiTricity

WiTricity, a portmanteau for "wireless electricity" [refers to] devices and processes which use a form of wireless energy transfer, the ability to provide electrical energy to remote objects without wires using oscillating magnetic fields.

This sounds like such a potential shift in how we conceive of electr ...[text shortened]... faster? The article mentions "well-known physical laws", but can someone be more specific?

I thought it was delayed because they were still doing test on the effect of the exposure to the magnetic fields.

http://www.wirelesspowerconsortium.com/technology/emf-limits-icnirp-basic-restrictions.html

Originally posted by Palynka
This sounds like such a potential shift in how we conceive of electronics in general. So why hasn't this developed faster? The article mentions "well-known physical laws", but can someone be more specific?

My son has a rechargeable electric tooth brush. You place it to charge in a holder that has no obvious metal contacts whatsoever. The toothbrush itself is waterproof. It must be using WiTricity to charge.
I believe there are mice that can be charged that way too.

Originally posted by twhitehead
My son has a rechargeable electric tooth brush. You place it to charge in a holder that has no obvious metal contacts whatsoever. The toothbrush itself is waterproof. It must be using WiTricity to charge.
I believe there are mice that can be charged that way too.

That's great, but the range is still not enough to make it significant, right?
I imagine that if you can develop an equivalent narrow, low-divergence (laser-like) means of transporting energy that could mean huge shifts in electricity distribution, for example.

Originally posted by Palynka
That's great, but the range is still not enough to make it significant, right?
I imagine that if you can develop an equivalent narrow, low-divergence (laser-like) means of transporting energy that could mean huge shifts in electricity distribution, for example.

I think it is all a question of who needs it.
If there is a power loss of say 10% if your mouse charges wherever you leave it (and an extra monetary cost), then is it really necessary? Even a docking station that charges your mouse is less common than simply removing the batteries and recharging them - and even more common of course is putting a wire on your mouse.
If 99% of people won't pay the extra cost to put batteries in their mouse, how big is the market for a device that charges those batteries remotely?

Also, for any kind of range I can imagine safety issues to be a major concern. Even if it was perfectly harmless I would think twice before switching on a device that gets power from one side of my head to the other.
On a side note, I get headaches from using cell phones (and microwave cookers) and can actually sense when they are making a call near by - especially when reception is poor as they step up the power.

What are we talking about here? Sending energy wirelessly? It's done every day!

The sun gives us energy in form of electromagnetic radiation from a distance of 150 millions of kilometers. Is this really unknown? This is what I call sending energy wirelessly!

Saw an article a while ago where Sony had a flatscreen TV powered wirelessly.
This is not it, but close enough: http://www.techchee.com/2009/10/03/sony-wireless-power-transfer-promises-total-wireless-hdtv/

Originally posted by FabianFnas
What are we talking about here? Sending energy wirelessly? It's done every day!

The sun gives us energy in form of electromagnetic radiation from a distance of 150 millions of kilometers. Is this really unknown? This is what I call sending energy wirelessly!

We are more focused on both sending and receiving energy efficiently between the home electricity system and home devices - possibly without line of sight, and hopefully reasonably harmlessly.
I am sure we could send energy across the room with a laser, but it not only needs line of sight but would be highly dangerous. It could also be done for power transmission from a power station to houses, but again, it would be subject to physical interference (clouds, trees, birds) and highly dangerous especially to birds (or aircraft if it was high enough).
The reason why sunlight works is that it is not a high enough concentrations to be very dangerous - which is one reason why it is so inefficient. Most large solar plants must either have very large and expensive solar panels or must first concentrate the light with mirrors.

Having said that, we do already use the technology to power solar powered calculators, watches etc - often by use of a light bulb rather than the sun. However, the technique is only suited to very low power devices.

Originally posted by twhitehead
We are more focused on both sending and receiving energy efficiently between the home electricity system and home devices - possibly without line of sight, and hopefully reasonably harmlessly.
I am sure we could send energy across the room with a laser, but it not only needs line of sight but would be highly dangerous. It could also be done for power tra ...[text shortened]... light bulb rather than the sun. However, the technique is only suited to very low power devices.

That's right. And this is also why power wireless distribution of energy is doomed to fail (in the immediate future, the far future maybe can show us some solutions, but now?, no.).

As long as copper is so cheap, the methods are quite safe, and the technology is available, then wireless distribution of grand scale is not possible. The technology is there but not usable.

Originally posted by FabianFnas
That's right. And this is also why power wireless distribution of energy is doomed to fail (in the immediate future, the far future maybe can show us some solutions, but now?, no.).

As long as copper is so cheap, the methods are quite safe, and the technology is available, then wireless distribution of grand scale is not possible. The technology is there but not usable.

As already discussed, for specific uses, the technology is already there and already in use. The most common ones are where the device in question is extremely close to the charging apparatus. For example a device that is typically 'docked' when not in use but needs to be waterproof eg a toothbrush or a device that can sit on a charging device all the time eg a mouse.
Copper is the most efficient and sometimes the cheapest solution, but as we are seeing with communication, that can be more of a hassle than it is worth - hence the explosion of wifi. In fact, wifi is nearly at the point where it is cheaper than copper, though for raw speed, copper still wins.

I am sure we could design a device that could charge almost all small devices whenever they are in range - eg cell phones, mice, digital cameras, watches etc, but there needs to be a strong market to get it off the ground before the device manufacturers will build their end into the devices. Currently there is no really pressing need.