Shop OBEX P1 Docs P2 Docs Learn Events
Control wire lengths — Parallax Forums

Control wire lengths

ArchiverArchiver Posts: 46,084
edited 2003-01-21 00:24 in General Discussion
Does anyone know what the max length of wire would be that you could
use for a switch or a pot to the stamp?
Ian

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-01-20 23:24
    There is no magic number. You need to know the size of the wire, voltage
    drop, ampacity of the wire, etc,etc.
    20 GA copper may be only 20 feet, and a 4/0 superconductor may be 1million
    miles.

    What kind of length are you looking for. Another length problem is noise on
    the conductor.

    Sorry this isn't a good answer, but the question is like asking how much
    sunlight does it take to boil water?

    Alan Bradford,
    Plasma Technologies


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-21 00:24
    Probably 100' or more for a very low current signal. I would
    definately clamp the I/O pin to +5 and GND with 1N4148 diodes and add
    a 100 ohm series resistor to dampen out and ringing on the line.
    Basically a long wire acts like a LC tank circuit so you definately
    could generate a voltage spike large enough to smoke your I/O pin.

    Jason

    --- In basicstamps@yahoogroups.com, "iphillipsca <iphillips@s...>"
    <iphillips@s...> wrote:
    > Does anyone know what the max length of wire would be that you
    could
    > use for a switch or a pot to the stamp?
    > Ian
Sign In or Register to comment.