Stepper motor controllers are electrical circuits used to deliver information to the stepper driver, which controls the function of a stepper motor. The stepper motor controller may be incorporated into the design of the stepper driver. In some cases, stepper motor drivers are programmed with an initial set of commands that do not change. These drivers are a form of stand alone stepper motor controller. In other cases, the programming of the driver is altered by a separate stepper motor controller to produce various movements.
The stepper motor controller sends out a pulsed signal to the stepper drivers. The signal order can be input by an equipment operator, or it can be a programmed set of commands. This signal is interpreted into commands by the driver and relayed to the motor by energizing or de-energizing the windings.
The advantage of using stepper motor controllers, rather than stand alone drivers, is in the added control of the motor's functions. While basic stepper drivers control a limited amount of functions, stepper motor controllers are able to manage movements on a wider scale. Microstepping, multi-axis control, and other functions are possible with the use of stepper motor controllers. In addition to controlling the direction of movement, stepper motor controllers also register and manipulate the speed and exact distance of the movement.
In some cases, multi-axis controllers are used. This type of stepper motor controller enables the control of several stepper motors from one point. These advanced stepper motor controllers are used in applications where precise control of synchronized movements is required. With the ability to control the functions of several motors at once, these controllers can create the fluid movements needed for precision manufacturing equipment.
Stepper motors and drivers are available in both bipolar and unipolar motor configurations. When stepper motor controllers are used, the controllers must be matched to the appropriate motor and driver type. The key difference between the two types is the number of windings for each step.
A unipolar stepper motor has two windings for each step because the electric current only travels in one direction. This type of stepper motor requires the driver to activate pairs of windings, rather than a single winding per step. The bipolar stepper motor allows electric current to flow in both directions through a single winding in each step. The stepper motor drivers used for this type of motor only need to activate one winding for a single step. The stepper motor controller is responsible for signaling the driver to activate the windings that, in turn, create the desired movement.