Slashdot Mirror
Wireless Power Recharging Nears Fruition
AlexanderT writes "Mobileread.com is reporting that wireless power recharging of mobile devices may become commercially available by the end of this year. Various recently filed patents by Cambridge UK-based Splashpower Ltd. indicate how close the company is in realizing this technology."
Bah, Tesla did it ages ago.
Wanna get nasty? - DaNasty
When I saw the title about wireless charging, RF (Radio Frequency) came to mind.
Then I RTFA (Articles / Advertisements) and realized that they are in fact talking about inductive coupling.
Inductive charging cradles have been used by Sonicare® for several years to charge their cordless toothbrushes.
It pretty cool anyway!
All the worlds indeed a
At first I read the summary and freaked.
Wireless Power!
My mind raced witht the possible applications...this lasted 1/2 of a second. Then I stopped writing new sci-fi reality in my mind, read the company's website. It's really cool but has no where near the applications of TRUE wireless power.
How is this wireless charging, if you need to place the object on a specific pad ?
Sure, there's no actual wire connection to your phone - but it's not like you can just walk around within N feet of some 'emitter' and the phone will charge.
That specific pad still has to plug in somewhere.
And that pad is larger than any travel adapter for a mobile phone - so you won't be taking one with you anytime, which means you'd have to rely on one being present wherever you decide to go ? I don't think so.
And these plates have been around for years. It's called induction charging.
The only place where I might just see it happening is in airports - but given that most devices will not work with this pad, but will still work with a regular charger, I don't see any airport opting to do away with their regular sockets and getting these plates instead.
Yes, but the problem was that if you got close enough to the changing station, it would charge you, in the form of 40000000 kajillion volts. They were also monsterously ineffecient, his test models that could power an acre with usable amerage were the size of light houses. Nowadays, we also know that having that much EMI around constantly will give you cancer in short order. What this company is probably doing is called inductive coupling. This is a relatively simple phenomina. When you have lots of electrity running through a coil, then you place some more wire inside the coil, current is generated in the second coil. This is not a long range effect, so don't think that when you walk in your front door your cell phone and laptop will start charging. It would be more of a "place the device on the special box, no plugging it in" kind of thing. My question is how much power it uses. Induction is much weaker than conduction, so it seems like a laptop that requires 30W of power to recharge would need 1000W to run through the charging mat. I wonder how much more people are willing to pay on their electric bills so they don't have to plug their laptops into the power adapter every day.
Actually, it won't be as high as you think. As it is an inductively coupled system, it relies on magnetic coupling between the charger and the PDA, etc. It is essentially a power transformer where the secondary winding can be removed. If only the primary remains (i.e. there is no device on the charger) the only energy lost will be the magnetizing current of the primary. Granted, this will be a high-frequency power source, so there will be additional losses in the primary side semiconductors, etc., but it's not like this device is powering the whole room.
Inductive charging systems are considerably more than 3% efficient. It's nothing but a transformer with no magnetic core and somewhat less coupling than usual. Depending on the physical layout of the charging and receiving coils, energy transfer efficiency can easily be greater than 90%, and the least little tiny bit of intelligence on the part of the charger will have it shut down the charging coil when not needed...
If systems that used magnetic induction between two coils for energy transfer were so inefficient, we wouldn't use these things called transformers EVERYWHERE. In fact, that was the whole point of Tesla's preference for AC power...
Ce n'est pas un vrai mouvement de robot!