Working mode of stepper motor driver

1. The whole step drive

In the whole step operation, the same kind of stepping motor can be equipped with either the whole/half step driver or the subdivision driver, but the operation effect is different. The stepper motor driver circularly excites the two coils of the two-phase stepper motor according to the pulse/direction instruction (i.e., charging the coils to set current). Each pulse of this driving mode will move the motor by a basic step angle, i.e., 1.80 degrees (there are 200 step angles in one circle of the standard two-phase motor).

2. Half step drive

During single-phase excitation, the motor shaft stops at the whole step position. If the driver receives the next pulse and keeps the other phase in the excitation state one after another, the motor shaft will move by half a step angle and stop between two adjacent whole step positions. In this way, the two-phase coil is subjected to single phase cyclically, and then the two-phase excitation stepping motor will rotate in a half-step mode of 0.90 degrees per pulse. Compared with the whole step mode, the half-step mode has the advantages of double precision and less vibration in low-speed operation, so the half-step mode is generally selected when the whole/half-step driver is actually used.

3. Subdivision drive

Subdivision drive mode has two advantages: minimal vibration at low speed and high positioning accuracy. Subdivision drives are widely used in stepping applications that sometimes need to run at low speed (that is, the motor shaft sometimes works below 60rpm) or the positioning accuracy is less than 0.90 degrees.
Its basic principle is to precisely control the current of two coils of the motor according to sine and cosine steps, so that the distance of one step angle can be divided into several subdivision steps.