The mode of stepping motor driver, stepping motor and stepping motor driver form a stepping motor drive system.
The performance of the stepping motor drive system depends not only on the performance of the stepping motor itself, but also on the advantages and disadvantages of the stepping motor driver.
The research on stepper motor driver is almost synchronized with the research on stepper motor.
There are three basic stepping motor driving modes for stepping motor drivers: whole step, half step and subdivision.
The main difference lies in the control accuracy of motor coil current (Excitation mode).
1. Whole-step Drive. In the whole-step operation, the same stepping motor can be equipped with either whole/half-step drive or subdivision drive, but the operation effect is different.
The stepper motor driver circulates the two coils of the two-phase stepper motor according to the pulse/direction command (Setting current for coil charging)
, Each pulse of this driving mode will move the motor by a basic step angle, I . e. 1. 80 degrees (
The standard two-phase motor has a total of 200 step angles in one circle).
Mode 2 of stepper motor driver, half-step drive, when single-phase excitation, the motor rotating shaft stops at the whole step position, after the driver receives the next pulse, if the other phase is magnetized and kept in the excitation state, the motor shaft will move half of the step angle and stop in the middle of the two adjacent full step positions.
In this way, the two-phase coil is cyclically single-phase and then the two-phase excitation stepping motor will be 0. 90 degree half step rotation.
All full/half-step drivers supplied by Shanshe motor can perform full-step and half-step drives, which are selected by the dial position of the driver dial switch.
Compared with the whole-step mode, the half-step mode has the advantages of double precision and less vibration during low-speed operation, so the half-step mode is generally used when the whole/half-step driver is actually used.
3. Subdivision Drive. Subdivision drive mode has two advantages: low speed vibration, minimal vibration and high positioning accuracy. For sometimes low speed operation (
That is, the motor shaft sometimes works below 60 rpm)Or the positioning accuracy requirement is less than 0.
In the 90-degree stepping application, the subdivision stepping motor driver is widely used.
The basic principle is to carry out precise current control on the two coils of the motor according to sine and cosine steps respectively, so that the distance of a step angle is divided into several fine steps.
For example, the driving mode of 16 subdivision can make the stepping motor with 200 standard steps per turn achieve the operation accuracy of 200*16 = 3200 steps per turn (That is, 0. 1125 °).
In general: in the state of full-step operation, for each input pulse, the angular displacement of the motor shaft is a step moment angle. In the state of half-step operation, for each input pulse, the angular displacement of the motor shaft is half a step moment angle.
It is better not to use the stepping motor in the whole step state, which has large vibration.
TAG stepper motor driver