Hi, I am trying to control the speed of a unipolar stepper motor using a potentiameter.
The specification of the stepper motor is as below.
-Operating voltage : DC 4V
I just need this stepper motor to turn one direction and hopfully, I need to increase or decrease its speed by adjusting a potentiameter.
I once arranged a stepper circuit using two ULN2003 chips to cope with the above stepper motor before. I used Darlington transistor array for a unipolar stepper motor in this tutorial.http://www.tigoe.net/pcomp/code/category/code/arduinowiring/51
Since the current of the stepper motor is almost 1A, I parrelelled two ULN2003 so that the chip could cope with the motor's current needs.
The circuit diagram of the stepper motor is this.http://www.flickr.com/photos/34955071@N02/3947745034/#sizes/o/
Could you advise me where and how can I put a potentiameter?