Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Power Hardware

Flexible, Plastic Sheets of Power 127

bethr writes "Imagine never having to plug in an electronic device to get power? Researchers at the University of Tokyo have demonstrated prototype plastic sheets with copper coils that wirelessly supply power to any device that touches its surface. You just put down your laptop and the pad sends it power: 'An array of organic transistors that detect the position of the gadget and direct current flow.' Apparently, the researchers had enough time to create a spiffy video of their doll house model, complete with a mini Christmas tree, showing off the technology."
This discussion has been archived. No new comments can be posted.

Flexible, Plastic Sheets of Power

Comments Filter:
  • Slashpads? (Score:5, Interesting)

    by soleblaze ( 628864 ) on Sunday December 31, 2006 @01:41AM (#17414516)
    Isn't this kind of like Slashpads [splashpower.com]?
    • Re:Slashpads? (Score:5, Interesting)

      by Pooua ( 265915 ) on Sunday December 31, 2006 @01:45AM (#17414536) Homepage
      The difference appears to be that this prototype only applies power to the section of the sheet on which the device is placed, instead of to the entire device. Supposedly, this results in a greater amount of power able to reach the device being charged. I am wondering how much of an improvement in performance this really is?
      • Re: (Score:3, Informative)

        by TheRaven64 ( 641858 )
        This kind of technology has been around for a while. The problem is not the technology, it's the lack of standards. If someone like the IEEE published a standard for induction charging that specified power and some kind of handshaking protocol between the charger and the device, it would be great. Imagine just putting your laptop down on the table in a coffee shop or in work, and having power and networking automatically work.

        Without standards, however, the situation is the same as for mobile telephon

      • Re: (Score:1, Insightful)

        by Anonymous Coward
        How efficient are these things? I would imagine it takes more watts to do it wirelessly than it would if you used a normal wire.
      • Re: (Score:3, Interesting)

        by Fordiman ( 689627 )
        Mouse-powering mouspad

        Also, you'd only need to place the power-catching end of this tech on the battery itself. Nifty.
      • Re: (Score:2, Interesting)

        by cbacba ( 944071 )
        Improvement?

        It sounds like a massive increase in ambient EM noise just so a few lazy SOBs don't have to plug a power cable into a plug - not to mention another point of power loss (and waste) on the energy scene.

         
    • The sheet form factor allows for seamless integration with floors, walls, and furnitures.
  • Wow! (Score:3, Funny)

    by LiquidCoooled ( 634315 ) on Sunday December 31, 2006 @01:42AM (#17414524) Homepage Journal
    They have reinvented the transformer, except this time there is an open end on it.

    They had better paint it bright red and put warning signs over it, or it will start melting anything placed upon it.

    (I assume I am not the only one to throw my keys and change and the rest of my pocket crap out when I get home)
    • As I understand it, one of the things about this project is that the system detects if an object needs power and only send power to where the object is. Thats one of the reasons they can pump even more power into the object, because they can concentrate power around the object.
      • Re: (Score:3, Interesting)

        by EinZweiDrei ( 955497 ) *
        Forgive my sophomoric understanding of the science involved here, but I have a few questions to throw out there for the grad students and pedagogues:

        First, how does one define the abstraction of the pad detecting, as the parent puts forth, if an object "needs" power? What's to stop it from sending just as much power to a piece of conductive metal, say, a penny, as opposed to a cellular phone?

        [As I'm sure someone will naturally assume I'm supposing that a penny is comprised entirely of highly-conductiv
        • Re:Wow! (Score:4, Funny)

          by EvanED ( 569694 ) <evaned@g[ ]l.com ['mai' in gap]> on Sunday December 31, 2006 @09:09AM (#17415834)
          From TFA:
          The power sheet, says Takao Someya, professor of engineering at the University of Tokyo, relies on the well-known physical principle of electromagnetic induction, used to charge electric toothbrushes and some RFID tags. (Emphasis mine)

          So the device more or less tells the pad that it wants power.
          • Re:Wow! (Score:4, Informative)

            by Rolo Tomasi ( 538414 ) on Sunday December 31, 2006 @11:35AM (#17416412) Homepage Journal
            Read again. It doesn't say that there's any sort of communication involved, what they're saying is that RFID tags use the principle of electromagnetic induction.
            • by EvanED ( 569694 )
              Oops. I think that computers should come with some sort of lock where you have to pass a simple mental function test before you can use them to prevent things like posting to /. when you're dead tired. ;-)

              Yeah, I can't read; my original post should probably be modded down, and/or you up. (/. needs a -1, misinformative rating...)
        • The article says that the object receiving power from these pads has to be equipped with a power-harvesting coil or some such. So I think it doesn't so much sense what's on it as just require the right kind of object to be placed on it.
        • by MikeFM ( 12491 )
          Will magnetic induction hurt a penny or set of keys? I would assume they have taken into account things like disk drives being placed near the device since they mention laptops. Just being metal wouldn't necessarily mean it'd be detected as needing power.
  • Cost? (Score:4, Insightful)

    by Harmonious Botch ( 921977 ) on Sunday December 31, 2006 @01:50AM (#17414552) Homepage Journal
    Last time I was buying them at home depot, a socket was 79 cents and a cord was a few bucks. Why should I want to replace an already mature, tested, cheap, reliable technology with something that costs a whole lot more, and may direct power to where it is not wanted?
    • Re: (Score:2, Funny)

      by rrohbeck ( 944847 )

      Why should I want to replace an already mature, tested, cheap, reliable technology with something that costs a whole lot more, and may direct power to where it is not wanted?
      Because it's cool? Inefficient? Expensive? Conspicuous consumption and all that.
    • Re:Cost? (Score:5, Insightful)

      by djupedal ( 584558 ) on Sunday December 31, 2006 @02:22AM (#17414680)
      Concept...you know - an idea that prompts another idea, as an example?

      Your .79c socket matured decades ago, and will willingly flow power to any conductor able to penetrate one of the hot slots. And despite your very rigid non-stated Edwardian beliefs and desire to put-down something that falls outside that dormant little box you live in, these sheets won't be available @ HD any time soon at any price, so put away the fud and go back to reading by candle light :)

      They are simply another proof-of-concept...something the Japanese love to put on display, of course. I can imagine being able to lay devices on such a device to charge my cell-phone, etc. - anything needing charging...flashlite; iPod; bluetooth headphones; police radio; personal vibrator; PDA...a circuit to detect and communicate with whatever is in contact would be trivial, and an obvious part of any marketable product. You could drop conductors on it all day long, including water, and without a controller to initiate power to the contact zone, nada. Lick it for all it cares.

      Recall the topic here recently about China and South Korea moving to standardized chargers? This falls into the same area, being concept-driven, as it seems to be. Additional/separate & wired chargers would be 'standardized' (as in gone) because they would not be needed with something like this around. The charger-less product would then sell for less, since your home or apartment or hotel room or office desk or car/boat/plane/train armrest would already have one of these built-in.
      • Re: (Score:3, Insightful)

        Thing I don't get is why manufacturers don't move to a USB standard charger connector. Even allows data transfer if you want to let the phone do that (no stupid assed, weird serial cables). Motorola for one has been using those on their phones for a while, and other mobile devices. It's nice China & South Korea are showing some initiative though. It'll take time for us to see though as to if manufacturers will actually do it. A penny more for a licensed connector vs something you build yourself for a pe
        • Is USB a good charging mechanism? USB only provides 5 volts [wikipedia.org], and according to Wikipedia it may only give 500 mA to a device. Isn't that a bit too little to charge mobile phones and laptops?
          • I charge my Nintendo DS off USB constantly. It's only marginally slower than using the normal mains, as far as I can tell. You can only supply so much electrical (I don't know whether to say "charge" or "power" here) to a device at once, I guess.
          • USB works just fine charging phones. My Treo 650 for example has a max charge rating of 5.2v over 1A. Normal USB would just take twice as long to charge. Chargers however that use the USB connector can, and do deliver a higher amount of power. Just because they use the connector, does not require they deliver 5v over 500mA.
      • You're right. Some people never think outside their box. Even if it doesn't make it to HD anytime soon for house use, my daughter would LOVE that little dollhouse thing they made. This could make cool board games too, or like you said, a desk that powers small DC devices.
    • Ease of use (Score:1, Informative)

      by Anonymous Coward
      If they can make this cheap (a few bucks?) then I would prefer it to having to plug my cell phone in. Much easy to lay my cell phone down flat than plugging it in (and sometimes breaking the connector after n uses). Same with laptop (cause I move around with it a lot).

      I agree not everyone is willing to pay a few extra dollars for ease of use. But there are some who do. For example, I know people who bought the iPod over cheaper competing products with equal capacity because they preferred the click wheel na
    • Re:Cost? (Score:5, Interesting)

      by GoulDuck ( 626950 ) on Sunday December 31, 2006 @06:15AM (#17415316)

      Last time I was buying them at home depot, a socket was 79 cents and a cord was a few bucks. Why should I want to replace an already mature, tested, cheap, reliable technology with something that costs a whole lot more, and may direct power to where it is not wanted?

      Why should I have X different chargers for my wireless devices? Imagine your desk if this was build into the table... your phone don't need a wire, wireless mice charge no matter where they are located, your keyboard always works, your PDA is charged when placed on the table and so is your laptop. You could have wires for all these things, but if I could avoid having x numbers of cradles and loose wires on my table, I would like that even more. And as I type this, I could imagine other things: Wireless hard disk (with wireless USB) and wireless desktop speakers, just to keep it in the nerd world and what about your desk lamp and the LCD picture frame :-) And you thought that I was done there? When a friend comes over and discovers that his phone is low on battery and your phone charger doesn't fit? Imagine your friend to be able bring "anything" without having to bring any wires at all.

      This will also solve allot of the cable clutter under the table. Just think of all the things on your table that needs power and then imagine them without wires... Imagine this build into the walls - your speakers, tv and lights didn't need wires! Well, I don't know how it reacts to a nail, but there might be solutions for this too, like having a device that can sense where these things are placed, so you can go around them with your nails and screws.

      Surely I can't be the only one excited about the possibilities with this kind freedom you can have?

      • by pakar ( 813627 )
        Wireless Mouse - Just have a capacitor that could power it for a few houres since you move the mouse around and could make it difficoult to charge.
        Wireless Keyboard - Just have a capacitor that could power it for a few hours since you might have it in your lap from time to time.
        Wireless speakers - Same as for the mouse/keyboard but should only need a capacitor that can last for a few minutes since they should be quite stationary.
        Monitor - No need to connect a powercord to it ie less cables
        Computer - No need
      • by Tim C ( 15259 )
        Well, I don't know how it reacts to a nail, but there might be solutions for this too, like having a device that can sense where these things are placed

        Anything that can draw power from it would be suitable, as long as it informed the user that it was currently doing so; you wouldn't necessarily even need a special device for it. Eg hold your laptop/mp3 player up to the wall, move it around and wait for the "coupled to charger" light to go off.
    • by EvanED ( 569694 )
      These wouldn't exactly be cheaper, but I paid $30 for a charger for my cell phone a couple weeks ago. (Don't shop at the Cingular store for stuff like.) Even the 3rd party one that Best Buy or Circuit City was like $22...
    • You should look behind my home theater system (which includes not just the 5-speaker stereo and DVD, but a HTPC, game consoles... you get the picture). I was just yesterday thinking how cool it would be if I could somehow eliminate that rat's nest of wires.
    • Seems like we've been asking (and answering) this question for a long time. (Eras are rough but you'll get the idea)

      1700 - Candles or Kerosene
      Lots of folks didn't see the need to upgrade to kerosene lamps. Kerosene cost money whereas, if you didn't mind getting stung a little, you could always make plenty of your own beeswax candles for nothing but the cost of your own time and effort.

      1800 - Fireplace or Cookstove
      Many people thought that cooking and heating a home with a stove was a pale comparison to gathe
  • Great idea! (Score:2, Informative)

    by tehSpork ( 1000190 )
    Nicola Tesla [wikipedia.org] would be proud...
  • Might be expensive..

    I know some doctors, who feel that wires (to power/recharge their equipments) is a big distraction when they want to focus on examination. This could be a good news for them.

    • Well, they'd have to be extremely careful in the operating room. The leakage currents on these pads could be enough to hurt someone who's been opened up.
  • And you'll have the Triforce of Power. haha, i'll be here all my life!
  • Efficiency? (Score:5, Interesting)

    by Frogular ( 961545 ) on Sunday December 31, 2006 @02:22AM (#17414678)
    How efficient are these compared to regular adapter + cable? The lack of a magnetic core may mean your utilities bill goes up x2.
    • by Tim C ( 15259 )
      It really depends what you intend to use the tech for. No, going from something drawing 500W to 1kW is not good. However, going from a 1W draw to 2W may well be worth it if the convenience factor is great enough, at least individually (on the scale of a society, it may still be less than desirable, of course).
      • by Xayma ( 892821 )
        But if it also reduces the number of devices (phone chargers and the like) drawing small amounts of power when not in use it may be better for the environment.
  • Is this the same principle as how my wife charges her vibr... ahem... Sonicare toothbrush?
  • Combine? (Score:1, Interesting)

    by Anonymous Coward
    That and this [newscientist.com] together could make for an interesting tent one day, amongst other things. Add in flexible displays [cdtltd.co.uk] etc and you could be applying for research grants from DoD and DHS. Portable command centers anyone? Portable geek huts?
  • by HateBreeder ( 656491 ) on Sunday December 31, 2006 @02:46AM (#17414750)
    So.. wouldn't it be reasonable to assume that it would cause serious electrical interference to sensitive devices, such as laptops?
  • by edwardpickman ( 965122 ) on Sunday December 31, 2006 @02:58AM (#17414774)
    Remember the scene in A Christmas Story where the kid licks a metal pole? I keep getting this picture of a kid licking the power strip and the electronics deciding his tongue was an electronic device badly in need of a 120 volts. I can hear the chanting now, "you'll blow your eye out, you'll blow your eye out."
  • How does it differenciate between the different wattages that all my devices take? I don't want to start cooking my ipod because this thing is giving it laptop voltages...
    • uh.. you plug the laptop and the ipod into the same wall outlet now, don't you ? think of this as just removing the cord which goes between the wall and whatever device. of course, with this, now you have to put the device right at the outlet, which sorta blows. eg, you couldn't have a cordless lamp getting power while standing on a plain antique table. ps, differentiate.
  • by Joebert ( 946227 ) on Sunday December 31, 2006 @03:07AM (#17414800) Homepage
    Here's a few things I'd like to apply this stuff too.

    1) Wireless mouse pad
    2) Magnetic track-type lighting
    3) Stove top -- Pots/pans/ect would have their own unique heating elements & the entire stove top would be usable

    I'm sure there's plenty of practical applications for somthing like that plastic power...
    4) Power strips with 100% usable surface area.
    ... power strip stuff.
    • Re: (Score:3, Informative)

      by Sparr0 ( 451780 )
      inductance-using Wireless mouse pad [tweaknews.net]
    • Re: (Score:3, Informative)

      by drawfour ( 791912 )
      3) Stove top -- Pots/pans/ect would have their own unique heating elements & the entire stove top would be usable
      There's already something similar to this -- induction cookers [wikipedia.org].
      • by Joebert ( 946227 )
        Man, it's starting to look like this stuff is good for nothing more than fancy track lighting & power strips with plugs that come loose all the time.
    • Re: (Score:2, Funny)

      1) Wireless mouse pad

      Q: "Sure, but where does the mousepad gets its electricity?"

      A: "It's mousepads all the way down."
      • by Joebert ( 946227 )
        I think you'll agree that the mouse pad plugging into the USB port & sporting a wire would be better than the mouse having the wire.
        Wouldn't need to place a mouse in a charger either, just leave it sit on the pad.

        But, as an earlier replier already pointed out, there's an alternative.
        • I don't know, it seems that mouse + mousepad + wire is more annoying than mouse + wire. There is also the additional need to keep the mouse on the mousepad, so if I need to make room for a coffee mug I need to move everything.
          • by Joebert ( 946227 )
            Silly consumer, in the retail world, you would simply buy a bigger desk, one with a coffee holder, to solve that problem. :)
    • 3) Stove top -- Pots/pans/ect would have their own unique heating elements & the entire stove top would be usable
      Your stove has detected new hardware - ShinyPot 2007. Please insert drivers into oven.
      • by Joebert ( 946227 )
        Man: Is that a new set of pots and pans ?
        Woman: Oh theese old things ? Heavens no.
        Stove 3000 : *coughbullshitcough*
    • Re: (Score:3, Informative)

      by repvik ( 96666 )
      "3) Stove top -- Pots/pans/ect would have their own unique heating elements & the entire stove top would be usable"

      Those are called "Induction tops", and are readily available (Atleast here in Norway). You buy special pots/pans/etc for your special stove. Induction heats the pots/pans/etc, and *only* those. Advantages are amongst others rapid heating, rapid cooling of the stove, no restrictions on placement on the stove.
    • by igny ( 716218 )
      1) wireless mouse's wired pad

      There, I fixed that one for you.
  • by Anonymous Coward
    Physicists Promise Wireless Power [slashdot.org]is cooler.... Check the article also to preempt the cancer paranoia comments (aka toxoplasma [slashdot.org] talk [slashdot.org] ) and tesla refferences. This looks more like a demo of the organic, flexible transistors. It could be done with more conventional electronics. I don't quite see the point over a magnetic connector or something, either. The mention of "resistance" in TFA should be replaced with "reactance", should it not?
  • Hrm (Score:4, Interesting)

    by umbrellasd ( 876984 ) on Sunday December 31, 2006 @03:28AM (#17414836)
    Would be neat if we could put something like this in roads. Vroom! There's already a lot of power near roads. Electric cars that charge as you drive. Refueling is automatic; cars check in at a pay station once a month for a meter read.
    • by Dwedit ( 232252 )
      That happened a long time ago [wikipedia.org], sort of.
    • Which also reminds me, I wish we had a way to convert all the heat that the black asphalt roads absorb during the summertime into energy we can use in cars. Have you ever put a bare foot on the street at 8pm after a 103F day in the summer?
      • Thermodynamics makes this almost impossible. The second law [wikipedia.org] says that it is hard to do useful work with energy that is spread out like the heat on an asphalt road. If you try to get energy from heat, you can not do any better than Carnot efficiency. A machine that transfers heat from a 100F road to 60F air will be less than 7% efficient.
        • Not very practical from a materials perspective, but some efficiency gain might be possible if the underside of the driving surface was insulated and heat was piped through that layer to the cooler earth below it. Again, not very practical from a material costs perspective (probably), but TD might not entirely kill the idea.

          On the other hand, if you can make the driving surface out of thin film voltaics or have a transparent driving surface with a voltaic layer below it, you wouldn't have much of that he

  • Obviously the Tesla effect is not what's interesting here. Its the direction of power to the device that is interesting. You have this big power sheet and it only sends power where there is a device that needs it.

    The obvious place for this power supply is your chair and bed. You can sit down with your cell phone in your pocket and have it recharge while you work at your computer.

    The big deal application of this kind of technology is probably computer implants. Its hard to change the batteries of a compu
  • You can easily try this at home yourself. Just disable the safety switch on your microwave, and run it with the door open.

    You can induce up to a kW in things like forks and aluminium foil.

    It even warms up my hands and head on the inside while I hold my devices near the oven.
  • This has actually already been invented but not lasted because of multiple reasons. Maybe vaporware, maybe not but the waiting game is still a factor for them too. Good luck though. I have a lot of wires that I don't like to plug in all this electronic crap that gives me tumors.
  • Turn blue (Score:1, Troll)

    by jamesl ( 106902 )
    This is me not holding my breath.
  • Did anyone else notice the second LED turn on while the little model laptop was close to it, but NOT making contact? Energy in the air, mang!
  • by Shaiku ( 1045292 ) on Sunday December 31, 2006 @05:47AM (#17415232)
    Apparently a lot of readers don't understand what induction is, and that this power pad works off that principle. Power isn't routed to a device on top of the pad like many people seem to think. There's no electrical contact between the power source and the device on top of the pad. The device in need of power will have a coil of wire. The power pad will detect where on the pad the device is and then create a virtual coil of wire underneath the device. The two coils of wire do not touch, but they are near enough each other that they create and air-core transformer. In other words, AC current traveling in the pad's coil will electro-magnetically INDUCE an AC current in the device's coil. This is really, really old science. The problem is that in order to transfer a significant amount of power efficiently, the two coils have to be closely coupled to one another. This means that the power pad's coil has to have a small cross-section and be located directly under the device to be powered. By detecting where the device is with, say, a pressure sensor, and then using semiconductors to dynamically route a current in a virtual coil directly underneath the device, this power pad allows for the device to be placed haphazardly in virtually any location on top of the pad. This is the same principle that Sonicare toothbrushes use to charge, but imagine now being able to put the toothbrush anywhere on the counter to charge instead of inside a dedicated charging station.
    • by Lupu ( 815408 )
      Instead of a simple pressure sensor I would see a lot more potential in the technology if it paired with a wireless verification protocol, to ensure that the device indeed is capable and willing to accept the charge. This would help avoid misbehavior in cases such as throwing your keys on the pad(which was used as an example of concern in an earlier post).
      • Nowhere in the article does it say there are pressure sensors. It says it uses resistance changes to detect a target. The keys example is also fud, there's no support from the article that keys would be detected as a target, or even used as a target.
    • by cas_edi ( 970079 )
      i concur that the FUD on this slashdot topic is contemtable i would also like to add that you would not require a pressure sensor, just placing a coil object that has a load would be enough for the pad to initiate power. the other thing some people seemingly have no clue about it that every piece of cabling and transformer in your home generating a magnetic field when the 240V/110V travels through it (basic physics again) and to claim this device with generate dangerous EMF levels is just ludicrous. with
  • He did that decades ago, and actually had the idea instead of recycling it. Wasnt practical then either.
  • As they note in the article, this is a refinement on Inductive Charging [wikipedia.org]. I used to love my inductively charged toothbrush; place it on it's stand (just a smooth white bump), and it charged, no physical electrical contact required.

    Does anyone know why they need to actively sense the location of the object, and route the energy specifically to it? Inductive energy isn't "consumed" unless there's a draw on it. For example, a common example of induction is in a wall-wart transformer; one set of windings goes
    • Re: (Score:3, Interesting)

      by Overzeetop ( 214511 )
      The coils do need to match up, and there are losses for coils running without a primary load (resistance in the coils themselves, for example). For a really large sheet of coils (there are multiple small coils in the sheet), that could add up, and add a thermal load to the space that might not be insignificant.

      There are certainly some interesting applications, but the cost will likely be prohibitive for the "electrified wall/floor" in the foreseeable future. Working in the building industry, I can say for c
  • Although I like the idea I'm wondering about radiation/emission issues. We're already surrounded by quite a lot of emissions which are to a degree shielded.

    In this case shielding is obviously not possible , and it's also not exactly lossless. I'd stick with a cable.

    Having said that, I'm looking for something to get 12V 30mA on the other side of a 10mm glass sheet so I haven't decided yet if that's better done magnetically or via capacity.
  • Is this not more useful? wireless extension cord [thinkgeek.com] The contact requirement of the pad almost seems as much of a tie down as a wire. Plus, with the wireless you can probably reheat your coffee while on the laptop by just raising you mug in the air...
  • ...an electric toohbrush?

    Mine sits on a stand which recharges its internal battery by induction, so such a thing is hardly a big surprise to me! It's an ideal case for inductive power: a device which gets wet in use, needs to be hygienically sealed, recharging uses very little power, and there are no sensitive electronic devices nearby for it to interfere with.

    Mind you, electric kettles are a similar case, yet modern cordless kettles seem to have worked out how to do safe direct electrical connection e

  • The whole-house idea is overambitious, but, on a smaller scale, it would be a great way to recharge portable devices. You'd have a pad, or maybe a shallow tray, where, at night, you put your small portable devices - phone, music player, PDA, electric razor - for recharging. It would need to be standardized, so that all the gadgets could use a common system. You'd have one tray at home, probably in the bedroom. A travel version roll-up pad with a cord and wall transformer would be necessary. Deployment

  • If you accidentally put a credit card down on the pad and then put your laptop down to charge, will it damage the card? I could see this as being a problem with magnetically sensitive things. Also, will it interfere with CRT monitors? (Yes, some people still use them.)

    -b.

  • Sell a pad like a big mousepad and compatible replacement batteries for an existing laptop. Since most laptops have batteries on the bottom, you could have your laptop continually trickle-charged while it's sitting on the pad.
  • Nobody will buy this unless it works with most devices. Would you pay (say) $129.95 to eliminate two cords out of the dozen on your desk?

    For it work with most devices, device makers would need to be willing to standardize on it.

    If device makers were WILLING to standardize, we wouldn't HAVE umpteen different kinds of wall-wart transformers with different voltage and current requirements... and different DC plug configurations.

    If every device used the same DC voltage and the same kind of low-voltage DC plug,
  • Didn't Nikola Tesla do this about 100 years ago?
  • Introduced in 2002, the Wire-Free Electricity Base by Mobilewise [electronicproducts.com] was the first device to interrogate loads placed upon it in order to deliver tailored power. Sadly, there were no takers and it faded away.

We are each entitled to our own opinion, but no one is entitled to his own facts. -- Patrick Moynihan

Working...