What voltage should I input in DRV8825 driver?

Support Motor controllers/drivers and motors
1

Hello,

I am using several DRV8825 (in parallel), each one controlling one Nema stepper motor.
I plugged the circuit on my power supply (max. 30V - 10A), currently set on 20V constant voltage.
I understood how to control the current in the motors coils, turning the potentiometers screws.

I read that the DRV8825 can take between 8.2V and 45V. How should I decide which voltage I input in the driver (currently, 20V). I tested voltages from approximately 10V to 25V to see what changes, but I can’t figure it out clearly.
What does the input voltage change in the DRV8825 behaviour? Is it in my interest to increase or decrease this voltage applied to the drivers?

Thanks in advance

2

Higher voltages allow higher step rates, as the coil current increases more rapidly.

3

I moved your thread to the “Motor controller/drivers and motors” section of the forum since it seems more appropriate.

To get the rated specifications from your motor, you should use at least the voltage it is rated for. As Jim described, you can use even higher voltages to achieve faster step rates since the DRV8825 can limit the current. Please note that you should set the current limit on the DRV8825 to no higher than the rated current per phase of your stepper motor or 1.5A per phase (since that is the most our DRV8825 carrier can handle without additional cooling), whichever is lower.

Brandon

4

OK, thank you very much to both of you for your answers!

I read in my motors characteristics (Nema stepper 17HS19-2004S1) “Tension: 2.8V” so I understand I need to input at least 2.8V in it, but the DRV8825 minimum voltage is 8.2V so, anyway, I will have to input at least 8.2V.
I may not understand completely what you mean by “faster step rates”. Do you mean:

  • Will I achieve more torque?
  • More speed (ie. I would be able to set less delay between each step in my Python code)?

Thanks

5

The step rate determines the speed of the motor, so higher achievable step rates means higher speeds. It is possible that you might get slightly more torque while stepping before the motor skips, but the main benefit is the potential for higher speeds.

Brandon