When stepper motor off power, creates current if i manually rotate the shaft

Support Motor controllers/drivers and motors
1

Hello everyone…

As the name of the topic describes, i realized at a curtain moment, that if my power is off and i manually rotate my steppers’ shaft it creates a current that flows back to the whole circuit.
I know that is normal, but can cause some kind of problem to my circuit?? Has the DRV8825 has some kind of protection for that occasion? If not what can i do to keep the whole circuit protected??
I use the stepper motor Pololu 1472 and a DRV8825 and i have a capacitor 100μF between Vmot and Ground the driver.

Thanks in advance, Angelina.

2

Hello, Angelina.

Back driving a stepper motor that will generate a voltage at the driver outputs, so it is possible that could damage the driver. However, it is pretty uncommon for us to hear about that actually causing problems, so unless you anticipate your motor being back driven at a really high velocity, or while attached to something with a lot of inertia, I do not think you have to be too worried about it. If you have an oscilloscope, you could measure the voltage on one motor output pin while back driving it to check.

- Patrick

3

Thanks a lot Patrick, for your answer and help.

Angelina.

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