Adding external power to a keyboard

Discussion in 'Modding and Hacking - Consoles and Electronics' started by Quzar, Feb 11, 2010.

  1. Quzar

    Quzar Spirited Member

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    My keyboard sits about 35ft away from my desktop and is connected via an extension cable. This arrangement works fine for your average keyboard, but the whole point of it (over wireless) is to use one of my IBM Model Ms. The Model M however draws close to the max of the PS/2 spec for power and won't run off what makes it over the extension cord.

    So, a few questions:
    1) Would it be harmful to directly attach a 5V wall wart to the keyboard?
    2) I'm not an expert with circuit design, not with translating technical specs. It seems as though the computer recognizes a keyboard being attached via the power draw, to it seems I'd have to somehow have both power sources attached at once ... or some sort of slightly more complicated deal in there.

    I've looked around and haven't been able to find this having been done before or I'd take a cue from that.

    Any hints/tips/advice would be greatly appreciated.

    Thanks
     
  2. alphagamer

    alphagamer What is this? *BRRZZ*.. Ouch!

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    You could have something other than the keyboard draw the 5v from the PS2 (a LED e.g.) and then supply the keyboard with external power. That way you have both circuits separated.
     
  3. Quzar

    Quzar Spirited Member

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    Well, gave it a try. Got basically no results. Took a PS/2 to AT adapter I had clipped the AT side off of, and the cable from a broken KB matched the clock and data lines and left the 5v and ground wires unconnected. Took the computer side and attached it to an LED and took the keyboard side and attached it to a receptacle that matches a 5v wall wart I have. Made sure the polarities are going the right way (... I really hope? I took - (o + to mean center pin positive, outer negative).

    When connected the lock LEDs blinked (as is standard for plugging in the keyboard) but no real connection. Some keys I hit will trigger the computer's speaker to bleep but that's about it.

    It seems there is a chance that the power lines are somewhat broken as when I wiggle the adapter bit the kb LEDs will blink again (as if unplugging and replugging).

    Any advice?
     

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