Why does the torque decrease as the speed increases?
    Because when the stepper motor rotates, the inductance between the various windings of the motor becomes an electromotive force in the opposite direction, once the frequency of this electromotive force is getting higher and higher, the speed of the motor will increase, but the phase current will also decrease correspondingly, and the natural torque will decrease.
    Stepper motor can operate normally at low speed, but if the speed is too high, there will be no way to start and noise.
    This stepper motor is also for the industry to read the technical parameters:
    1 no-load start frequency, in short, is the stepper motor in the case of nothing to start the pulse frequency, if the pulse frequency exceeds this frequency, the stepper motor can not start normally, and there will be lost step and blocked phenomenon.
    2. In the case of load: when starting, the starting frequency will have an acceleration process, if the starting frequency is relatively low, there will be an acceleration process only to raise the speed to the speed we need, which is 3.0 times the pulse of the no-load starting motor.