Operating a DC Motor Clockwise/Anticlockwise with a Single Switch Circuit

The following post discusses the wiring connections for driving a DC motor in clockwise and anticlockwise directions with the help of a single toggle switch and a relay circuit. The idea was requested by one the interested followers of this blog. Let's learn more:

The Circuit Request

Hi,

please help.

We have our project in school.

Our professor asks us to design a transistor together with a relay that allows a motor to rotate clockwise and then , a switch will be press , then will rotate counter-clockwise.

Thanks in advance.

The Circuit Design

A DC motor can be very simply rotated both ways in clockwise as well as in anticlockwise directions by flipping the supply inputs to it.

However the above reversing requires flipping of both of its wire polarity with the connected supply.
Therefore it cannot be done by using a single relay or switch.

However by using a couple of relays, a single switch operation becomes feasible for toggling the connected DC motor in both directions.

The following circuit shows the wiring details of the relay with the motor which is controlled by a transistor driver stage.

On switching power ON, the motor starts rotating in either clockwise or anticlockwise direction depending upon the wire polarity of the motor.

When SW1 is pressed, the direction gets instantly reversed and continues until S1 is switched OFF.

Actually the transistor stage is not required here, the implementation could be done simply with the relays and SW1.
More simply, the whole operation can be conducted using ordinary DPDT toggle switches.


 

22 thoughts on “Operating a DC Motor Clockwise/Anticlockwise with a Single Switch Circuit

  1. Have questions? Please feel free to post them through comments! Comments will be moderated and solved ASAP.
    • the relay contacts are wired such that the motor receives (+) and (-) supplies across its terminals, the above polarity simply reverts when the relay is activated by pressing SW1, and vice versa.

  2. Hello Swagatam,

    I really like your projects and ideas. I have one question about above circuit. I have same the DC motor driver circuit except two separate switches for fwd/ rev. The issue is when i run the motor, the relay's strip contact will shot. I think it is because of "back emf" or high current. Please advise what is the cause and how to resolve that.

    Thank you

    • It's not because of back emf, back emf won't damage relay contacts…it's probably due wrongly rated relay contacts….your motor is consuming more current than the maximum relay contact specs.

      using powerful relays is the only solution.

  3. Hi, I'm the one who asks this and I forgot to say thank you. It really helps. Thank you. I wish you'd continue helping others. God bless.

  4. Hello i'm a real noob when it comes to electronics :p Can this motor go counterclockwise to iff I use a DPDT switch? I need a mini motor for a cosplay project so it can spin both clock and counterclockwise.



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