Setup on Arduino Uno Rev3 with 2 12V motors and 1 High Torque servo

Hello,

I am pretty new to the Arduino world and I have a question concerning the setup for my project. I am using 2 12V 120RPM DC motors and 1 high torque servo and I was wondering what setup with my Arduino Uno Rev3 would work best. I figured I would need an H-bridge for the 2 motors, and knowing the voltage range of the servo is 3-7.2V I would maybe need to attach it also to an external power source as well as the two motors. I understand this may not be the case if I am not using too heavy of a load though so the 5V running through the Arduino may be fine. I wanted to get some feed back on the simplest way to get this to work with my Arduino. I have a few ideas in mind, but I wanted to get some feedback from more experienced Arduino users. Any help would be appreciated.

Thank you.

Hi, welcome to the forum.

Using the Arduino 5V pin for a servo motor is not fine at all. Even a cheap normal servo motor can have peak currents of 0.5A or even 1A.
The Arduino 5V output is not strong enough for that.

If you start with a 12V power supply, you might try to power the Arduino with that (to the power jack or to VIN). But I rather would use two DC-DC converters. One for 7.5V or 9V for the Arduino and the other for 6V for the servo motor.

I'm curious about your ideas...

Durand42:
Hello,

I am pretty new to the Arduino world and I have a question concerning the setup for my project. I am using 2 12V 120RPM DC motors and 1 high torque servo and I was wondering what setup with my Arduino Uno Rev3 would work best. I figured I would need an H-bridge for the 2 motors, and knowing the voltage range of the servo is 3-7.2V I would maybe need to attach it also to an external power source as well as the two motors. I understand this may not be the case if I am not using too heavy of a load though so the 5V running through the Arduino may be fine. I wanted to get some feed back on the simplest way to get this to work with my Arduino. I have a few ideas in mind, but I wanted to get some feedback from more experienced Arduino users. Any help would be appreciated.

Thank you.

You need to provide links to datasheets or specifications for all the motors/servos.
“High torque” means little, an actual part number with datasheet is the information
needed. To me high torque might mean 1000Nm, to you 1Nm

You will not run the servo from the Arduino 5V, that will just cause grief and/or damage.

Okay so another external power source for the servo was well. That won't be an issue. The servo motor is high torque in a sense that the torque rating is 13 Kg/cm. High torque for a hobby servo. My application probably won't need the maximum torque by any means, but we wanted to be safe. The two DC motors are 12V 120 RPM motors with a none load bearing current load of .6A and we have run some tests to see what our maximum current pull would be and it came out to be 2A. This won't be a problem though as we have an external power source as well for those.

As for the breadboard setup, what would be the best design?

Thank you.

Durand42:
As for the breadboard setup, what would be the best design?

That will depend on the H-bridge you choose. If for example you chose an L298-based* one, you need 3 control wires per motor; others only have 2 (dispensing with an enable wire). I have a Pololu driver which doesn’t even need 5V logic supply, it has only the motor voltage and presumably takes the logic power from there.

Have a squiz here for Pololu’s driver range.

  • you won’t, will you?

the torque rating is 13 Kg/cm

kg.cm you mean 8) small-k, and times not divide

Yes, I think a Pololu driver could work for this application. It would save some space as well. And yes, thank you for the correction! Being new to all this there is a lot to be learned since there are many different ways to do these simple tasks. All of your help was useful and appreciated.

Thank you.