Stepper motor (screw stepper motor) is an open-loop control element that converts the electrical pulse signal into angular displacement or linear displacement. In the case of non-overload, the speed of the motor and the stopping position depend only on the frequency and number of pulses of the pulse signal, and are not affected by load changes, that is, to add a pulse signal to the motor, the motor turns a step Angle. The existence of this linear relationship, coupled with the stepper motor only periodic error without cumulative error and so on. It makes it very simple to control with stepper motor in speed, position and other control fields.

Although the stepper motor (screw stepper motor) has been widely used, the stepper motor can not be used as an ordinary DC motor, and the AC motor is used in a conventional manner. It must be composed of double ring pulse signal, power drive circuit and other control system can be used. Therefore, it is not easy to use a good stepper motor, which involves many professional knowledge such as machinery, motors, electronics and computers.

At present, the production of stepper motor (screw stepper motor) manufacturers are indeed many, but with professional and technical personnel, can develop themselves, the development of manufacturers is very few, most of the manufacturers only one or twenty people, even the most basic equipment is not available. It's just a kind of blind imitation. This causes a lot of trouble in product selection and use. In light of the above, we decided to take a wide range of inductor stepper motors as an example. The basic working principle is described. Hope to be helpful to the majority of users in the selection, use, and improvement of the whole machine.

Stepper motor (screw stepper motor) dynamic indicators and terms:

1, step Angle accuracy:

The error between the actual value and the theoretical value of each step Angle of the stepper motor. Expressed as a percentage: error/step Angle *100%. The value of different running beats is different, and the four-beat running time should be within 5%, and the eight-beat running time should be within 15%.

2, out of step:

The number of steps when the motor is running is not equal to the theoretical number of steps. Call it out of step.

3, offset Angle:

The rotor tooth axis offset the stator tooth axis Angle, the motor operation must have an offset Angle, the error caused by the offset Angle, the use of subdivision drive can not be solved.

4. Maximum no-load starting frequency:

The maximum frequency at which the motor can be started directly without load in a certain drive form, voltage and rated current.

5, the maximum no-load operating frequency:

Motor in a certain drive form, voltage and rated current, the highest speed frequency of the motor without load.