The stepping motor has a technical parameter: the no-load starting frequency, that is, the pulse frequency that the stepping motor can start normally under no-load conditions. If the pulse frequency is higher than this value, the stepping motor cannot start normally, and the stepping or blocking may occur. turn. In the case of load, the starting frequency should be lower.

       If the stepper motor driver is to be rotated at a high speed, the pulse frequency should have an acceleration process, that is, the starting frequency is low, and then rise to a desired high frequency at a certain acceleration (the stepping motor speed is increased from a low speed to a high speed).

       The error between the actual value of the stepping motor and the theoretical value per revolution of the step angle. Expressed as a percentage: error / step angle * 100%. The values of different running beats are different. The four-shot operation should be within 5%, and the eight-shot operation should be within 15%.

       The number of pulses or the conductive state required to complete a periodic change of the magnetic field is represented by n, or the number of pulses required for the motor to rotate through a pitch angle. Taking a four-phase stepping motor as an example, there is a four-phase four-shot operation mode, that is, AB- BC-CD-DA-AB, four-phase eight-shot operation mode is A-AB-B-BC-C-CD-D-DA-A.

       The locking torque of the stepping motor shaft under the action of rated static electricity and the motor does not rotate. This torque is a measure of the size of the stepper motor and has nothing to do with the drive voltage and drive power. Although the static torque is proportional to the number of electromagnetic excitation amps, and is related to the air gap between the fixed tooth rotors, it is not preferable to reduce the air gap excessively and increase the static ampere to increase the static torque, which will cause the motor to heat up and mechanical noise.

       Once the stepping motor is selected, the static torque of the stepping motor is determined, but the dynamic torque is not. The dynamic torque of the stepping motor depends on the average current (not the quiescent current) when the motor is running. The larger the average current, the stepper motor. The greater the output torque, the harder the frequency characteristics of the motor. In order to make the average current large and increase the driving voltage as much as possible, a stepper motor with a small inductance and a large current is used.