drv8825 operating voltage vs a4988

Anybody with experience of using the drv8825 outside of a ramps/reprap setup? I have a stepper driver board to drive micro steppers running at 6v . The stepstick work seamlessly but i had some drv8825 boards and tried them and they wont work. I checked the datasheet and it said the operating voltage of the drv8825 is 8.5-25v and of the stepstick is 8-25v . The only difference is that the drv8825 creates its own logic voltage internally. Could that be a issue to run at 6v ?

Yes, that could well be an issue. I advise against running either board at below its minimum rated voltage, because the chips in those boards need that minimum voltage to guarantee correct operatio

Bear in mind that both the boards you refer to are constant-current drivers, so you can turn the voltage up to 8.5V or more without damaging your steppers provided that you set the driver current to within the rating of the micro steppers. You might need to change the values of the sense resistors on the board to get the current range to go low enough for your motors.

Another possibility is to run the boards at (say) 9V and connect a resistor in series with each stepper motor winding to reduce the voltage appearing across the winding to 6V.

Can you provide a link to the datasheet for the motors?

Edited 1 time(s). Last edit at 12/19/2014 04:32AM by dc42.

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Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].