B-328 Motor Driver

I’m driving a 12volt motor with the B-328. It changes directions and speed very frequent. After a wile I get stuttering on the only one direction. I can run the motor the other direction at different speeds with no problem. I move the motor to the other motor control channel and no problems. But I’m sure that after a wile it might happen again. This is the second B-238 that I have done this to.

Should I add a diode or something to the motor?

Power StepUp - Pololu U3V12F12
Battery - 7.4V 2000mAh Li-ion
DC Motor - Volts: 12, No Load Current: 150mA, Rated Current: 900mA,

Thanks for the help!

Hi, Dan.

It sounds like the motor drivers are overheating, but I think the bigger concern is you seem to be powering the motors from a regulator that is under powered for this application. Could you try connection the motor supply voltage directly to the batteries and see if you still have the same problem?

Also, could you please tell me what the stall current of your motor is and post schematic of your setup?


I bypassed the Power Step-up and ran the motor for a few hours and it never stuttered, or killed the B328. But obviously the motors RPMs are less then what they would be on a 12 volt supply.

I’m not sure what the stall current is for the motor. But here is a link to the motor’s info. There is english translation next to the Korean words.: motorbank.co.kr/ab-1486235-5 … ut_ptr.php

Sorry for the lame schematic…

It looks like the stall current of that motor is close to 6A, so you will definitely need a more powerful regulator to power your setup (and possibly a more powerful motor driver since the TB6612 on the Baby Orangutan can only tolerate 3A peaks). A simpler solution would be to use a suitable 12V power supply rather than trying to boost a lower supply voltage.


Thanks for the help Derrill!
Part the goal of the project is to use that spasific power sourse. Is there a way to use a step-up regulator, and add some kind circut that would work as a breaker and trip if it hits about a 3A draw?

I know I could build something with the arduino to read the current and stall out. But it would be nice to have it hardware base.

Sorry, I’m not supper smart when it comes to the electronics side of things…

Thanks again for the help derrell!

If you want to use something to limit current, you might consider using a fuse. A step-up regulator that can handle that sort of current is likely to be expensive, and we do not carry any that would work.

Some things that you might consider doing instead would be:

  1. Use a suitably powerful 12V power source.

  2. Change to a motor that runs at 7.4V and that will not try to draw more current than the regulator you have can output.

  3. Take the regulator out completely and run the motor you have at 7.4V.