Hi,
I use your https://www.pololu.com/product/2133 stepper driver. What i need to so is holding the stepper at a certain position, so that the force of the driver is still active. Is this a danger for the driver of the motor, when i stay inside the recommended voltage and power-range? does the motor of the stepper get much warmer doing this? is there a recommendation, after which time i must rotate further? e.g. what will happen, if i hold the motor for half an hour?
All stepper motors have a current rating, which is the maximum allowed steady state current for each coil. It may instead give a voltage rating, which is equivalent to the current rating if you divide by the voltage rating by the winding resistance. One of the two maximum values is usually printed on the motor plate, but if not, you should look them up in the manufacturer’s data sheet for your motor.
If you do not exceed this rating the motor may get quite hot (even too hot to touch) but it will survive for very long periods.
Thank you, jim.
The datasheet for my stepper says its rated 6v. I am driving it with 12v on the driver. is that also ok in “holding mode”, as long as the driver output amperes meet the rated amount of the stepper?
Yes, if the motor is rated at a certain amperage, and you don’t exceed that amperage on average, then it should be safe. This means that the average voltage will be 6V, even though the max initial driving voltage is 12V; it’s often done to drive steppers with much higher voltage than “rated” so that they will provide more instantaneous torque, and then set the driver to control the max amount of current delivered so the motor doesn’t overheat.
Ohm’s Law is great for calculating things like this.
Again, to determine the winding amperage rating, divide 6V by the winding resistance. If the winding resistance is not stated, you should measure it with a multimeter.