Hi. I just want to verify my motor driver selection. We are using your 25D 12v HP motors and a 3 cell LiPo battery. So we assume a stall current of roughly 5.9A (i.e. 5.6A times 1.05). We want a robot to have four motors. Am I correct that the least expensive option is roughly $20-$25 per motor for the controllers (e.g., two of your #2507 Pololu Dual VNH5019 Motor Driver Shields for Arduino), and, that none of your motor drivers with a 5A stall current will work, even if we control the duration of a stall using current sensing? Thanks.
Hello,
You might be able to use something like our Dual TB9051FTG Motor Driver Shield for Arduino, but you would likely have to take some additional precautions to make sure you do not trigger the over-temperature or over-current protections. For example, switching directions at high speed can draw spikes of current upwards of twice the stall current, which is high enough to trigger the over-current protection, so acceleration/deceleration limiting might be needed.
We generally recommend choosing a motor driver that can continuously handle the stall current of your motor, so the VHN5019 shield sounds like a better choice with much less likelihood for problems or damage.
Generally, attempting control based on current feedback like you mentioned is difficult and not very reliable since the current can spike high enough to cause damaged faster than your feedback loop can react.
-Derrill
So, if we used a less powerful motor, such as your 20D 12v motors with a 1.6A stall current, you think we might run into problems using your TB6612FNG Dual Motor Driver Carriers (#713)? For us $3 and $10 makes a difference. We are trying to build the most powerful quad robot we can on a limited budget. Thanks.
The TB6612FN still seems underpowered for our 12V 20D motors and your 3S LiPo would be cutting it very close to the maximum input voltage for the TB6612FNG. I suggest our TB67H420FTG Dual/Single Motor Driver Carrier or our Dual MAX14870 Motor Driver Shield for Arduino with those 20D motors.
Please note, those 20D gearmotors have less power than the 25D motors you were looking at previously, so you should be sure whichever ones you pick are still appropriate for your application.
-Derrill