Potentiometer help

Discussion in 'General Electronics Chat' started by careless_monkey, Jan 11, 2011.

  1. careless_monkey

    Thread Starter New Member

    Jan 11, 2011
    17
    0
    Hey All!
    I'm looking for help in controlling a potentiometer. I'm just starting out to build a robot for my lab tech.

    What I want to do is that I have 2 wheels with motor connected to a shaft and hooked up to a 9V battery. I think I can make the wheels go forward, but in order to turn them I will need to use a potentiometer so that one wheel rotates less than the other. What is the best way to do this?
    I googled and found the three terminal potentiometer devices, but is there any other way to control the potentiometer?
     
    Last edited: Jan 11, 2011
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Pots typically aren't rated for the level of power you are using.

    If you are using a uC to control the speed/steering, add in a variable to slow the PWM on one driver so that wheel goes a bit slower. You could use a "balance pot", where the output is the input to a uC's ADC, but that is a bit overkill for what you are trying to achieve.

    Using resistance to slow a motor has many disadvantages, since the power is simply dissipated as heat. The maximum torque of that motor would be reduced, so the other side would "outrun" the slowed motor when under load.

    Using PWM for both motors is the simplest, and the best "start" to a uC robot, task 1: Make it go in a straight line (common problem)
     
  3. careless_monkey

    Thread Starter New Member

    Jan 11, 2011
    17
    0
    Thanks for the quick reply!
    I haven't thought of using the PWM in order to control the motor.
    I was also thinking of using Parallax micro-controller. All of this is very vague to me right now as I don't have any practical experience. Any suggestions that can help me understand more in depth of robotics and how to build a simple one?
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Here is a very simple PIC based one, you only need to change your code to match the intended code for your BASIC Stamp, it covers a bit about making it go straight. There are MANY MANY pages, so it takes a bit to get the full idea. The bright side, is those many, many pages allow you to build a basic robot platform on a breadboard, step by step, wire by wire.

    The PIC Project Page
     
Loading...