Are there different types of stepper motor controllers?
In fact, not every stepper motor controller is the same. For one thing, a stepper motor controller can be either open loop or closed loop. The difference between the two is that an open loop system sends a consistent rate of power to the motor, assuming that the rotating field that the rotor follows is consistent. A closed loop system uses feedback to adjust power based on the kind of load the motor is bearing. In other words, in a closed loop system, information is looping back to the controller, which then makes the necessary adjustments. In an open loop system, no feedback is provided. Most motor applications work with an open loop system, because it is simpler and less expensive. Since these applications generally call for a motor that will behave consistently, no feedback is needed, so it would be wasteful to opt for a closed loop controller. However, if the motor behavior will need to vary for maximum effectiveness, a closed loop system will be necessary.
