Electronic – Controlling Stepper Motors

stepper motor

I am controlling two stepper motors in from a Genie Microcontroller and driving them by a ULN2803A. I want to know what is the shortest time i can change the phase. Is it dependent on the ULN2803A?
Thanks in Advance,
Dean

Best Answer

The maximum rate you can move a stepper motor is based on the shaft torque and coil current. Attempting to move too fast against too high a torque will cause the motor to become desynchronized with the step impulses and move unpredictably/uncontrollably.

Here's a generalized graph:

Stepper motor graph

The whole curve shifts up and down with current.

Most drivers' speed will be orders of magnitude faster than any motor, the few exceptions are things with a bunch of protection/intelligence (of which the Darlington driver you linked has neither)