Slashdot Mirror

← Back to Stories (view on slashdot.org)

Typing Recharges Laptops?

Posted by CmdrTaco on from the sounds-crazy dept.

TwoSticks writes "Compaq patents a keyboard that captures your kinetic energy. Magnets and coils on each key charge a small battery to augment the big one in your laptop. Standard NYTimes deal: requires free registration. " I'm a bit suspicious but it looks interesting. It might give me an incentive to fix typos anyway ;)

4 of 140 comments (clear)

  1. view the patent by MbM · · Score: 3

    you can view the patent here

    http://www.patents.ibm.com/cgi-bin/viewpat.cmd/U S05911529__

    - MbM

    --
    - MbM
  2. Re:How much energy is there in your fingers? by Christopher+Thomas · · Score: 3
    Anyone care to hazard a guess how much energy can be extracted from your typing fingers, relative to how much energy the laptop consumes?


    Sure. This is actually pretty easy.

    • Assume that the force required to press a key is at most 1 N (roughly the force exerted by a 100g weght). More than this and I'm not using the keyboard :).

    • Assume that the keys move at most 1 cm (0.01 m) down when you press them. More than this gets silly.

    • Assume that I hit at most 10 keys per second sustained typing rate.



    Energy per keystroke is force * distance, or 0.01 J. Keystrokes per second times energy per keystroke gives energy per second (or power), which is 0.1 W.


    So, it doesn't look like this is viable unless we have *really* low power notebooks :).

  3. Lo battery? by Stavr0 · · Score: 3
    WARNING: Battery power is low.
    Save all your work now.

    Oh crap!!!

    askjhadslaashkjaasdkhdasasdsdhasdkasdsdajdashasdhd asdashdashshsdahaskdsahksdadsdaskjdaskhsdahsdaksda ksadsdhdashkaskhdashkdsasdahsdakdashshkahjdaskjasd sdflakldfslhjsfadhjlfsdakfdsalkdfsfdslffkdsalksjfk sdfafsdajhdfj;fdsajsdfahjfasd;jsdfa;fsdahsfadhjsdf

    Power has been restored. You may now resume work normally.
    - - -

  4. Estimation by amonymous · · Score: 5

    I'm not going to use a keyboard that requires
    me to apply more than 5 newtons to a key.
    Let's say the key course length is about 2mm.

    That's 10^-2 J per keypress, neglecting the losses
    in transformation from mechanical to electric
    energy.

    You need 10 keypresses to get 0.1W of power for
    1 second.

    Forget about having your notebook run on that
    alone. Keyboard power is somewhere between
    "little influence" and "neglectable".

    Could be more practical for a PDA without a
    hard drive, but then the trend for these things
    is not to have a keyboard at all.