DC polarity switching circuit for motorized toy

Discussion in 'The Projects Forum' started by mechanical_guy, Mar 4, 2011.

  1. mechanical_guy

    Thread Starter New Member

    Mar 4, 2011
    As my username implies...I may be too far out of water. I have located a similar thread, but there was not a response. Here is my simple project goal:

    Small DC motor that runs with 6V battery pack. I would like to have one button (when pressed) run the motor CW, stop when released (i think this is a momentary switch?) The second button, when pressed, runs the motor CCW until released. I can easily do this by swapping the terminals on the battery pack, but I am looking for a little more "elegant" solution for integration into an elevator-like toy project that I am building with my 7yr-old. Position of the motor is not required for the sophistication level of this project. Integrating a limit switch to break the circuit at each end of travel is my plan, if I have space. Ultimately, I would like to get to a continuous operation mode (push a different button, device stays on and automatically reverses when it hits the limit) - I'm guessing that there are some relays involved...but I am way outside my wheelhouse.

    I apologize in advance if this is not the right forum for this question...and if there is a "cookbook" solution out there, please point me in that direction. I realized after I started into this project that I am essentially emulating a low voltage drill driver that has a forward/reverse button...had I had one to cobble from, I would have started there...I am now looking for some guidance on a shopping list from Radio Shack and a quick schematic....

    Thanks in advance for your time and consideration!
  2. wayneh


    Sep 9, 2010
    Welcome to the AAC Forum!
    So far, very simple. Just use two momentary switches. A single, 3-position toggle switch would have the advantage of not being able to activate both directions simultaneously, which could be a problem with two buttons and a 7-year old.

    Yes, this is quite a bit more complicated but many here can help you with this.
  3. SgtWookie


    Jul 17, 2007
    This should pretty much do it for you:


    See if you can find 6v relays. If not, you could use 5v relays with diodes in series with the coils.

    [eta] You can use just about any diodes; the 1N400x series should be fine.

    If this is going to be battery operated, you don't want it to run continuously - unless you really like buying batteries.
    Last edited: Mar 4, 2011
    mechanical_guy likes this.
  4. mechanical_guy

    Thread Starter New Member

    Mar 4, 2011
    Thanks for the great (and quick responses) wayneh and SgtWookie - I am off to the 'Shack to give this a try. I agree with the battery comment. If this works well, I would likely use a discarded power supply/ wall wart.