Complete Stepper Motor Control Using the UCN4202 (MEC165E)

This shield circuit is adapted from my book Robotics, Mechatronics and Artificial Intelligence (sold out) published in the United States. It can be used as a shield for stepper motors in mechatronics or robotics projects or as a building block for more simple projects.

The UCN4202 (Sprague) is another IC that contains all the functions required by a complete stepper motor control. This IC is used in a basic configuration as shown by Figure 1.

Stepper motors with up to 500 mA per winding can be controlled by this circuit, without the aid of any driver transistor stage. If the current requirements of the motors are higher, you can add one of the driver blocks shown at the beginning of this chapter.


Figure 1    stepper motor control using the UCN4202.
Figure 1 stepper motor control using the UCN4202.



This IC’s control inputs are as follows:

The direction determines if the motor runs forward or backward, according the logic level.

The trigger enable is where the control pulses are applied, determining the speed of the motor.

In the step enable, you can brake the motor, as in the output enable.