Mechanical problem/help finding a circuit

Discussion in 'The Projects Forum' started by Rob1132, Jan 25, 2011.

  1. Rob1132

    Thread Starter Member

    Nov 4, 2010
    For those that helped me in the last topic I made here, you'll know I'm new and not very good at this stuff. Anyway, I bought a kit and actually managed to put it together and have it work. Most of it was pre-built, but I've been looking at ways of improving it and I figured this was a great hands on way to learn. Basically it's a seismic geophone kit that detects seismic vibrations and lights up a series of LEDs when it does depending on how strong the vibration. Anyway, it has a small wheel that turns on the circuit it came with to adjust the sensitivity of the sensor. I would like to put the parts into a project box or something to protect them and the sensor wheel is just too small to have stick out. So what I'm asking is, does anyone have any ideas or suggestions as to what I can possibly attach to the wheel to physically move it from a larger external piece? I'll attach pics below of the component and you can see there are actually small slits in it that looks like they may be able to have something put in them. I'm just not sure what I could rig up to have it work.

    My other question is, does anyone know where I can buy pre-built circuits like the one in my pic below? I want to make more of these kits and continue making variations, but the site I bought it from originally no longer has them. I can do it on my own if I knew where to get a circuit like this though. Thanks for any help.


    Here's the wheel. Again, I'm hoping to attach it somehow to a larger crank, knob, switch, etc. because it's really really small.


    And here's the circuit. I know it looks easy to make, but since I'm no good at soldering I'd much rather just buy a pre-built one if possible.
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
    Quote - "but since I'm no good at soldering I'd much rather just buy a pre-built one if possible. "

    The only way to get good at soldering is to practice :)
  3. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    That is a PCB potentiometer, you can get a larger one at Radio Shack, they usually come with 2-3" shafts, which you then cut off to size, and plop a knob on. You'd pull that one off the board, replace with 3 wires going to the 3 terminals on the new pot. Soldering 6 connections (each end of 3 wires), after desoldering the 3 existing holding the one in the photo in.

    The only thing that you need to know is the value. It should have a marking such as "103" or "252" or something straightforward like "10k".

    If you don't get the same value, all the range will either not be covered, or the full range will be passed in under a quarter turn, rather than nearly a full turn.