Reverse Polarity on a DC Motor

Discussion in 'General Electronics Chat' started by Wilhelm01, Jun 15, 2012.

  1. Wilhelm01

    Thread Starter New Member

    Jun 15, 2012
    Hi, I am new to the site and I have a question about reversing the polarity on a DC motor I have that controls a conveyor belt. I want to have it rotate one way until I receive a signal that tells the motor to reverse polarity. I would prefer to use relays if possible. Any help is greatly appreciated.
  2. MrChips


    Oct 2, 2009
    You will have to provide more details such as size and specs on the motor, even a photograph of the motor would help.
  3. colinb

    Active Member

    Jun 15, 2011
    As far as actually switching the motor drive current, there are two main methods that come to mind: (1) relays and (2) solid-state h-bridge (or equivalent form as an integrated solid-state relay or SSR).

    The relay will generally be simpler and cheaper when you are switching high power and especially may be a good choice when you aren't switching extremely frequently (e.g., not switching multiple times per second).

    Then you have to figure out the control for the motor drive controller relay or solid-state drive switch. As MrChips says, you'll have to provide more details to get a very useful answer. Ultimately, you'll probably end up with a logic controller of some sort, to implement the logic decisions like "go forward until the switch is closed, then go backward for 5 seconds, then stop". This can be done with simple discrete logic in an electronic circuit, but I personally think (and this is a very personal topic) you would be better off using a microcontroller to implement this logic instead of doing it with discrete logic or anything else. With a microcontroller you can do much more advanced things, without adding any new hardware. If you are a beginner to microcontrollers, the Arduino is a great way to start, mainly because it has a huge community and tons of tutorials to get you started.
  4. BillB3857

    AAC Fanatic!

    Feb 28, 2009
    A lot depends upon the way the motor is wound, if it has a field winding. If PM, then reversing the polarity to the wires will reverse the motor. If, on the other hand, it is a compound wound, or series wound, it is a lot more complicated. Like the prior post, motor info is needed before much more help can be given.