Two 24V dc motors, bidirectional


im currently working on a school project with two conveyors. Both run with a 24V motor that has a running current of 2A, starting current 8A (Datasheet, Model 111 3760 30 00). The motors need to be reversible, but they will never run at the same time.

Now my questions are: Which power supply do I have to use? Do I need one that can supply constant 8A or can it be less than 8A?

Also, how do i realise the motor control? I've searched via google but didnt find answers that really helped me on this, just a lot of terms I dont understand because I've never done anything like that. I need to control the motors in both directions, but not at the same time. I've read something about using N-Channel MOSFETs, but then I can only realise one direction.

We are using an Arduino Mega 2560.

Thanks in advance,

The power supply should be able to supply the maximum current for the motor. This may be a lower rated continuous supply but having a peak of 8A.

Research "H bridge". These allow motor control in both directions. You may have problems getting one suitable for your current at a reasonable cost. You may have to construct your own.


The Sparkfun Monster Moto Shield will handle this voltage and power easily, and it will run both motors. It uses a dedicated dual H-bridge chip that can do 36v and 30A.

With the Sparkfun shield, you can use analogWrite() to control the motor speed and slowly (half a second) accelerate it from stopped to running without exceeding 2A current. You can even measure the current in real time and modify the motor speed to suit. (You will need to do some modification to C1 and C4 to get sensible current readings.)

Find a power supply with some headroom, but 4A should be plenty of power if you never want to run both at once and you can ramp the speed up sensibly.

There's no 111.3760.30.00 motor on that sheet. Do you mean 111.3761.30.00 with stall current of 13A?

You have two choices - either use a supply that will current-limit when overloaded and
which is rated at less than the peak current demand (often this is enough,
since you do not need all that starting torque or you are ramping up via PWM).

Or you need a supply that can handle the fully stall current load without dipping - this
would be necessary if the supply handles overload by cutting out (which many switching
supplies do).