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Splashpower Boasts Wireless Power
Sullivan writes "Maccentral is running a story on a startup called Splashpower that hopes to be able to wirelessly recharge all of our handheld devices. They have a working prototype that already recharges an iPod Mini and a cell phone. Now we can look forward to yet another way to get brain cancer."
I think this is a very cool device and have often wondered why more devices haven't come with wireless re-chargability (think electric toothbrushes). But I wonder about the efficiency of this method. Is it? And if it's not, how less efficient is it than direct contact recharging? As more and more gadgets and devices become rechargable technology this would seem to be more important. I don't know much about electronics at the engineering level, so any erudite replies would be appreciated.
This is probably how Tesla would have charged his iPod.
My first thought when reading this: Build it in to a desk and use it as your mouse pad. Then, you would never have to charge your wireless mouse. Sweet.
--Nycto
No, but once (if) it gets built into phones, if you're away on a business trip and forget your cellphone charger you'll be glad the hotel provided a pad in your room.
My electric shaver recharges this way, and i've been wondering why we don't just have a pad that we can toss our electric gadgets onto for recharging.
My wish has been granted!
As for efficiency, I'll refer you to DansData, because he knows the answer to everything.
Your Answer Here
[Fuck Beta]
o0t!
You forgot "clean all of the lint and crud out of the charging port" and "wiggle phone around so the contacts make good contact rather than just barely missing" in your description of the old method. You also may have forgotton "make sure that cord is at such an angle so as to facilitate minimal breakage after grabbbing and walking away without remembering to unplug it in the morning". :)
Yes they did prove it...at least my college physics prof did by using a hypothetical line 1 foot above your head carring an impossible amout of power (1 million volts or somthing silly like that). The magnetic field generated by the line was several orders of magnitude less than the magnetic field of the earth which you are exposed to at all times.
Also the cell phone brain cancer thing is becoming less and less likely.
Apple free since 1990!
The efficiency is probably not at all bad; the magnetic field is short range and, in the absence of a receiver, the only thing in the magnetic circuit to absorb energy is the hysteresis of the inductor in the transmitter. Which, with modern ferrites, can be pretty small, unless of course they are using a purely air-cored system at the transmitter end, in which case it's tiny.
The huge potential benefit of this system is that it eliminates the second most unreliable part of electronic systems: connectors. Anyone who has worked at the sharp end of electronics knows that connectors suck, big time. Designs proliferate. There are far too many of them and they are far too unstandardised. And connectors designed to be repeatedly made and broken are the worst of the lot. Although the designs have come a long way (the fact that gigabit copper Ethernet connectors work is a small electronic miracle in itself) they are still the worst part of any system, after the batteries.
So here we have a system which if widely adopted allows most of the tiny connectors used in portable devices to disappear, and possibly reduces the demands on batteries because people will find recharging easier. Those are big pluses.
Panurge has posted for the last time. Thanks for the positive moderations.
Also, you're going to get less than .7 efficiency from the inductive recharger. The .7 efficiency on something like a toothbrush-charging stand assumes that the coils actually overlap slightly (know that little knob that the toothbrush rests on? It's actually part of the magnetic core that helps transmit the AC over). The electric field decreases with the square of distance. In one of those toothbrush chargers, the inductors are separated maybe by a millimeter of thin plastic. If you have... say a mousepad-sized recharging "station" to put all of your goodies onto, you might end up with distances of several inches from the charging coil to the pickup coil in the device you actually want to charge. Without having an actual "stand" like electric toothbrushes do, you aren't going to transmit much power. If you're going to have a stand, might as well have metal contacts, and forego the less efficient inductive method. The only reason why toothbrushes really do that is because they're often wet, and you put them in your mouth, so you wouldn't want metal contacts sticking out (my waterproof electric razor actually has metal contacts, you just wouldn't want to plug in the AC while it's wet).
Nothing says "unprofessional job" like wrinkles in your duct tape.
You're that guy from the TV commercials, aren't you? You know, the guy for whom straining spaghetti or wiping off a table or opening a jar are so incredibly difficult and frustrating that you have to swipe all your existing products off a tabletop with both hands and buy some special device to do it for you.