Error between actual value and theoretical value of step angle of stepping motor
The error between the actual value and the theoretical value of the step angle of the stepping motor and the error between the actual value and the theoretical value of the step angle of the stepping motor will affect the normal operation of the stepping motor. The no-load starting frequency in the stepping motor, that is, the pulse frequency that the stepping motor can start normally under no-load condition. If the pulse frequency is higher than this value, the motor cannot start normally, and step loss or locked rotation may occur.
In case of load, the starting frequency should be lower.
If the stepper motor driver is to rotate at high speed, the pulse frequency should have an acceleration process, I . e. the starting frequency is low, and then it should rise to the desired high frequency (Motor speed rises from low speed to high speed).
The error between the actual value and the theoretical value of each step angle of the stepping motor.
Expressed in percentage: error/step angle * 100%.
Different running beats have different values. Four beats should be within 5% and eight beats should be within 15%.
The number of pulses or the conductive state required to complete the periodic change of a magnetic field is represented by n, or refers to the number of pulses required for the motor to rotate a pitch angle. Taking a four-phase motor as an example, there is a four-phase four-beat operation mode, namely AB-BC-CD-DA-AB, four-phase eight-beat operation mode is A-AB-B-BC-C-CD-D-DA-A. The two-phase and three-phase ones are not listed here.
When the stepping motor does not rotate under the action of rated static electricity, the locking torque of the rotating shaft of the motor.
This torque is the standard to measure the volume of the motor and has nothing to do with the driving voltage, driving power supply, etc. Although the static torque is proportional to the number of ampere turns of electromagnetic excitation and to the air gap between fixed-tooth rotors, however, it is not advisable to increase the static torque by excessively reducing the air gap and increasing the excitation ampere turns, which will cause the heating and mechanical noise of the motor. Once the motor is selected, the static torque of the motor will be determined, however, the dynamic torque is not the same. The dynamic torque of the motor depends on the average current (Not Static current)
, The greater the average current, the greater the output torque of the motor, that is, the harder the frequency characteristic of the motor.
In order to make the average current large, the driving voltage should be increased as much as possible, and a motor with small inductance and large current should be adopted.
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