Uni-polar stepper motor

This post is only useful to know the basics of uni-polar stepper motor. This is very useful basics of uni-polar stepper motor when it is interfaced with micro-controller. And this post only shows the how to control Uni-polar stepper motor logically. If you want to know about step angle of the stepper motor and formula Click this link.

                      Stepper motor having two types one is uni-polar and second one is bi-polar stepper motor. Here I explain about Uni-polar stepper motor. Below diagram  shows the difference between these two stepper motor.

                                   

As you seen in above diagram Uni-polar stepper motor having five terminals namely A, B(A'), C(B), D(B') and final one is connected to Ground terminals. When your connected to micro-controller these four terminals(A, B, C, D) are controlled logically and you get different Step Angles using different logic's. It seems like this

As you seen above figure A, B, C, D terminals are controlled logically by using Micro-controllers.

If logic-0 or logic-1 is applied to all four terminals then angle made by the stepper motor is 0 (Zero) deg. Similarly some logic's are their as shown in below table.

This different logic's will help to get different step angles, when stepper motor is interfacing with micro-controller this logic's are very helpful to get different step angles. I will show you in next post how to interfacing stepper motor with micro-controller using above logic's.