What is a stepper motor and what's its purpose?
Step type stepper motor stepper motor according to the electromagnetic design is generally divided into: permanent magnet (PM), reactive (VR) and mixed type (HB), at the same time, the design according to the different excitation coil, the stepper motor can be divided into two phases, three-phase and five phase transmission; according to the design method, step motor and rotary stepper, linear stepper, and with gearbox with gear branch.Permanent magnet stepping is generally two-phase, torque and volume of small, step angle is generally 7.5 degrees or 15 degrees.Hybrid stepping is the advantage of mixing permanent magnet and reaction. It is divided into two phases, four phases and five phases: the two phase step angle is usually 1.8 degrees, and the five phase step angle is usually 0.72 degrees. This stepper motor is most widely used.
Number of pulses can be controlled by controlling the angular displacement, so as to achieve the purpose of accurate positioning; at the same time, you can control the pulse frequency to control the motor rotation speed and acceleration, so as to achieve the purpose of speed. Therefore, stepping motor is considered when accurate positioning or speed control is needed.
Stepper motor is a special motor as control, it is the rotation of the fixed point (called the step angle) operation step by step, which is characterized by no accumulated error, so it is widely used in a variety of open-loop control. Stepping motor is a kind of actuator that transforms electric pulse into angular displacement. Generally speaking, when the stepper driver receives a pulse signal, it drives the stepper motor to set a fixed angle (that is, step angle) in the set direction.
The phase number of the stepping motor refers to the number of coils in the motor. There are two phase, three phase, four phase and five phase stepping motors commonly used at present. The motor phase number is different, and the step angle is different. The phase angle of the two-phase motor is 1.8 degrees, the three-phase is 1.5 degrees, and the five phase is 0.72 degrees. In the absence of subdivision drive, the user mainly depends on the choice of different number of stepper motors to meet the requirements of step angle. If you use a subdivision drive, the number of phases becomes meaningless and the user can change the step angle just by changing the fine fraction on the drive.
