Hi, I just got two TB67S249FTG to drive two MS17HDBP4100 stepper motors from Moons.
They are NEMA 17, bipolar, 4 wires (don’t know if the coils are in parallel or series), Rated Current 1A, Holding Torque 0.82Nm, Resistance 5.6Ohms, Inductance 14.6mH and I only want to run them full step (DMODE 2 connected to the 5V of my Adafruit SAMD51 board using AccellStepper library).
The thing is that I have a sort of disturbing hissing noise when current go thru the coils (even without the motor moving) unless I put the board on standby. It’s very annoying since I wanted to use the config for a project in a quiet environment (something moving very slowly thru the day).
The only thing that changes the sound is when I raised the current limit. I need to be at VREF 800mV for the motors and the pitch changes if I modify that and actually stops if I go highter than 1.2V (or something like that) which is too high for the motors.
I tried the three different power supply (12V 5A, 12V 3A and a 19.5V 6.7A) with two different 100uF capacitors with the same result. They are not fancy power supplies though. Should I try a fancy one? Any suggestions?
Let me know if this is a common issue and if you think a solution involving some things to add to my circuit that could help or any other thing that I could try.
Best regards.
Romain
Hi, Romain.
Usually, the decay mode used by the stepper driver has a big influence on the audible noise the system makes. However, the TB67S249FTG has an Advanced Dynamic Mixed Decay feature that it uses to automatically select decay modes, and while we find that it usually works well, the driver doesn’t provide a way to manually select a decay mode to try to minimize the noise.
You mentioned that raising the current limit changes the sound; is it an option for you to lower the current limit? If you are not pushing the limits of the motor’s torque and speed capabilities, you might be able to reduce the current, which should decrease the noise.
If you have our full TB67S249FTG carrier (not the compact carrier), you might additionally consider trying different settings for the TB67S249FTG’s Active Gain Control feature, which allows it to dynamically reduce the current limit until the driver senses an increased load. In particular, you could try connecting the FLIM pin to GND, which disables the lower frequency limit for AGC and allows it to reduce the current limit while the driver is not stepping. (See the product page and the TB67S249FTG datasheet for more information.)
It’s possible that using different power supply voltages might influence the noise, but I am not sure that a higher or lower voltage would definitely reduce the noise, so it is likely something you would have to experiment with. Other than that, there might not be much else that you can try other than using a different stepper driver to see if it sounds different.
Kevin
Hi Kevin, thank you for your fast answer.
My problem is that the sound comes actually when I lower VREF bellow 1.2V (for all values bellow that). However, higher than 1.2V means a current limit of more than 1.5A which is too high for my motors and lower than that it does the sound.
Do you think the TB67S279FTG could be a better option since I wouldn’t have to lower the current limit as much?
Best regards.
Romain
I suspect the actual current limit is what matters, not what the VREF voltage is, so I don’t expect using the TB67S279FTG to make much difference in your setup. If you are open to trying a bigger board, the TB67S128FTG has a few selectable decay modes that might help with the noise.
Kevin
I’m about to order two of them, hopefully that will work.
I would appreciate if it was possible to have access to a coupon or a free delivery.
Do you have an idea on how and who to ask for?
Best regards and thanks again for the help.
Romain
We have an introductory special discount for the TB67S128FTG, and it looks like there are still some uses of that coupon code left. You can find the code on our Specials page.
Kevin
Thanks again, I got three. If that doesn’t work for this project, I’ll find another one for them.
Best regards.
Romain