Wireless recharging

[Moses Yoder]

I don't normally watch TV but since I now live 15 minutes south of Notre Dame I thought I should be a Notre Dame fan. I was watching the game today and saw an add for phones or something that charged wirelessly. I instantly saw the future; wireless electricity. Imagine the possibilities.

[charlie knighton]

i believe you have to be within certain distance to receive charging.......tests in airports......better than bundle of users trying to plug in......I believe they make lamps for home use where you can charge for individuals.......in the future who knows........I like fusion energy better......its why we are now gearing up for trip to mars....imagine......

[Ken Fitzgerald]

Picture this......a man wakes up deaf.....17 months later he gets a cochlear implant (CI) which consists of a special purpose computer implanted under the scalp and a sound processor that looks like and is worn like a hearing aid. There is a cable coming off the implant that actually is 16 concentric cables each terminated with an electrode that makes contact with the auditory nerve in the cochlea. The sound processor receives sound like a hearing aid but modulates a radio signal (RF) and transmits it through the scalp to the implant. The implant uses the RF to provide DC power for it to run and the modulation contains the computer software to tell the special purpose computer (the cochlear implant) which electrodes to excite when, how much and which polarity during the course of hearing a sound.

So the implant doesn't have a battery but uses the radio signal transmitted through the scalp to power it. No batteries to go bad or replace in the internal implant.

That's the way I and other CI-borgs hear today. The CI is wirelessly powered by a radio signal.

[Mike Henderson]

Those wireless rechargers (as least so far) are not very efficient. The closer you get to the source of the electrical radiation, the better the coupling - getting to the point where you lay your device on a "platform" to charge it. And even those are not as efficient as a cable.

I've seen some wireless rechargers proposed that you lay your phone on overnight. But I don't see a whole lot of advantage to that over plugging it in. Maybe a "remember" advantage where, as long as you put it in the right place, it will get charged.

The other thing is that as we shrink the semiconductors, they generally take less power so future electronics may require a lot less battery capacity, and thus be easier and quicker to recharge. Some things that we do inside phones, especially the radios (cellular, WiFi, Bluetooth), require a certain amount of power because they radiate that power, so that won't decrease.

Mike

[Moses Yoder]

Picture this......a man wakes up deaf.....17 months later he gets a cochlear implant (CI) which consists of a special purpose computer implanted under the scalp and a sound processor that looks like and is worn like a hearing aid. There is a cable coming off the implant that actually is 16 concentric cables each terminated with an electrode that makes contact with the auditory nerve in the cochlea. The sound processor receives sound like a hearing aid but modulates a radio signal (RF) and transmits it through the scalp to the implant. The implant uses the RF to provide DC power for it to run and the modulation contains the computer software to tell the special purpose computer (the cochlear implant) which electrodes to excite when, how much and which polarity during the course of hearing a sound.

So the implant doesn't have a battery but uses the radio signal transmitted through the scalp to power it. No batteries to go bad or replace in the internal implant.

That's the way I and other CI-borgs hear today. The CI is wirelessly powered by a radio signal.

Fascinating stuff. On another forum the question was asked "what decade would you want to live in" and I think we are in the best ones right now.

[Bruce Pratt]

Check out Nikola Tesla and Wardenclyffe Tower.

[Shawn Pixley]

Sonicare toothbrushes have been doing this for years. They used to make attachments for the Mobile phones. Now some have them built in. Me, I just plug mine in.

[Steve Peterson]

Wireless charging is similar to a coil of wire sending magnetic energy to a second coil of wire, essentially a transformer. Most normal transformers have a metal core and high efficiency. Wireless charging has an air core and low efficiency, especially at large distances.

As previously mentioned, electronics have become much more efficient so power requirements are reduced. On the other hand, cell phones do so many things that overall power requirements may be going up. Wireless cell phone charging is probably limited to setting it on a stand or in a special bowl at the end of the day. This prevents having to fiddle with the wire.

The micro-USB connection does seem to be the first thing that fails on many modern gizmos. Wireless charging is a good thing. You will still have to place the device into it's special location to charge.

Steve

[Rick Potter]

They even make pads you put on your garage floor. Park your electric car on it, and it charges. Big bucks, though.

Hey Ken, you don't get commercials on that implant do you? Think of the possibilities.... you go to sleep, and when you wake up you have a gnawing need to go buy a new Yugo.

[Kent Adams]

Moses, hate to break it to you, but Nikola Tesla came up with the idea of wireless electricity in 1911.

[Roger Feeley]

Yeah, that's inductive charging. It generally has some smarts. Resenz (used to be Alliance for Wireless Power ) has an inductive system that communicates with your phone via Bluetooth 4.0 (aka Low Energy, aka BT Smart). The charging pad and phone chat back and forth and the charging stops when your phone is full. Somehow, you can toss your phone, Kindle, iPad and other devices on the same pad and it will manage them all. Or so they say.

[Dan Hintz]

Those wireless rechargers (as least so far) are not very efficient.

Yes and no. An Energy Star-compliant wall-wart must be at least 87% efficient (and few are much more than that). An inductive charger for a similar item is around 75-80% efficient... not as far off as many think. If you move to high-frequency chargers, some are in the mid-80s, so fast approaching the Energy Star requirements (that one surprised even me).

I've seen some wireless rechargers proposed that you lay your phone on overnight. But I don't see a whole lot of advantage to that over plugging it in. Maybe a "remember" advantage where, as long as you put it in the right place, it will get charged.

One advantage is no more ports... which means a sealed body that can be made watertight.

The other thing is that as we shrink the semiconductors, they generally take less power so future electronics may require a lot less battery capacity, and thus be easier and quicker to recharge. Some things that we do inside phones, especially the radios (cellular, WiFi, Bluetooth), require a certain amount of power because they radiate that power, so that won't decrease.

As you shrink size, however, the ability to switch reliably becomes problematic... low-voltage (1.2V) components abound, but man, we're really approaching an asymptote with the current voltages. We'll need new technologies before we go any lower.

Radiated power can be decreased, too. More sensitive receive antennas, more efficient transmit antennas, and more efficient comm protocols would all lead to less wasted RF energy.