Hi, just tested my recently received G2-motor-driver. Used a potentiometer to change the pvm send by an Arduino to the driver; everything worked fine.
For changing the direction, I switched everything off, added 5V to the dir-pin and all good.
However: to simplify switching the direction, I implemented it in the arduino-code: potentiometer at 50% results in zero power for the motor, 0% in max power backwards by setting the dir-pin high and 100% sets max power forward.
It worked UNTIL maybe ten seconds of wild changing of the directions. Then two of the mosfets burned out…
Any sugestions/explanations?
Brushed DC motors can draw twice their stall current when commanded to quickly switch from full speed forward to full speed reverse, so it is not surprising that your driver would break under those conditions even though it was working while driving in one direction. If you post a datasheet for your motor or its stall current specifications, I might be able to confirm that it was likely large current spikes that damaged your driver.
Hey Claire,
thanks for your reply! Yeah, doubling the current by reversing the voltage sounds super reasonable! Don’t have a datasheet, but it’s a gear-motor from an electric wheelchair; 24V & 20A when running, so already quite at the drivers limit.
Do you know or think, if/that just the mosfets are damaged? (i.e. replacing them would repair the whole driver.)
I merged your posts, since they are about the same topic.
We do not release what FETs we use on our G2 high-power motor drivers, though you could probably use any low Rdson MOSFET in a 5x6 DFN package that can handle the current. However, when electronics like these are damaged often more than one component is affected, so there is no guarantee that replacing all of the FETs would repair the driver. It is probably best to try again with a more powerful board. Unfortunately, we do not have a significantly more powerful driver, and I do not have any recommendations for a driver with similar functionality but more current capacity. If you can use a different control method, you might look at the RoboClaw 2x60.
Hi Claire,
thanks for your advice! Due to my limited budget, I’m thinking of just re-buying the G2 again, to avoid rapid changes of the direction and to use a passive or active cooling-system as well.
I also will try to replace the MOSFETs and report my failure/success.
