一、Definition of stepper motor
A stepper motor, also known as step motor or stepping motor is an electrical motor that rotates in a series of small angular steps, instead of continuously. Stepper motors are a type of digital actuator. Like other electromagnetic actuators, they convert electric energy into mechanical position can be commanded to move and hold at one of these steps without any position sensor for feedback (an open-loop controller), as long as the motor is correctly sized to the application in respect to torque and speed..
二、Types of Stepper Motor
There are three main types of stepper motors, they are:
Permanent magnet stepper
Hybrid stepper
Variable reluctance stepper
1.Permanent magnet stepper：The rotor uses permanent magnets. The stator of this stepper motor is stamped into claw-shaped tooth poles, and the rotor uses radial multi-pole magnetize. This motor is low-cost.
working principle:The magnetic field generated by the coil current direction repels the rotor magnetic field, causing the motor to rotate forward/reverse.
2.Hybrid stepper:A hybrid stepper motor is a motor that integrates the features of a permanent magnet motor and an AC motor in one device, with the advantages of greater controllability, higher accuracy and lower noise.
working principle:Hybrid stepper motors rotate the rotor by continuously changing its magnetic field to achieve position changes. High-precision motion can be achieved, and hybrid stepper motors can be used in robots, wearable devices, medical devices and other fields.
3.Variable reluctance stepper:Variable reluctance stepper motor is an electric actuator with high precision and high efficiency. It is widely used in automation control systems.
working principle:The variable reluctance stepper motor uses the change of magnetic resistance to generate torque. It is a special stepper motor. Its rotor is equipped with multiple pole pairs, each of which is made of magnetic material. The coil on the stator generates a magnetic field through the current, and the direction and size of the magnetic field can be controlled by changing the direction and size of the current. When the magnetic field of the stator approaches or reaches the polar magnetic material, the material will be magnetized and become magnetically conductive, so that the rotor generates torque and the stepper motor will rotate.
