Stepper Motor Automatic control system
Stepper motor as an implementation of components, mechanical and electrical integration is one of the key products, widely used in a variety of automated control systems. With the development of microelectronics and computer technology, stepper motor demand is increasing, in all national economic areas have applied.
A stepper motor is an actuator that converts electrical pulses into angular displacements. It is popular to say that when the stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle (ie, the step angle) in the set direction. Can control the number of pulses to control the angular displacement, so as to achieve the purpose of accurate positioning; at the same time by controlling the pulse frequency to control the motor speed and acceleration, so as to achieve the purpose of speed. Reaction step is generally two-phase, torque and volume is small, the stepping angle is generally 7.5 degrees or 1.5 degrees; permanent magnet step is generally three-phase, can achieve large torque output, step angle is generally 1.5 Degrees, but the noise and vibration are great. In Europe and the United States and other developed countries 80 years have been eliminated; hybrid step is mixed with permanent magnet and the advantages of the reaction. It is divided into two-phase, three-phase and five-phase: two-phase stepping angle is generally 1.8 degrees and five-step stepping angle is generally 0.72 degrees, hybrid stepper motor with the number of (number of conduction windings) Step angle reduction, accuracy, this stepper motor is the most widely used. Stepper motors are commonly used in digital control systems with high accuracy and reliable operation. Such as the use of position detection and speed feedback, can also achieve closed-loop control. Stepper motors are now widely used in digital control systems, such as digital-to-analog conversion devices, CNC machine tools, computer peripherals, automatic recorders, watches and clocks, and other applications in industrial automation production lines, printing equipment. Stepper motor is a kind of induction motor, its working principle is the use of electronic circuits, the DC into a time-sharing multi-phase timing control current, with this current for the stepper motor power supply, stepper motor to work properly, the drive It is a multi-phase timing controller for stepper motor time-sharing. Although stepper motors have been widely used, stepper motors do not function like conventional DC motors. AC motor in the conventional use, it must be double-ring pulse signal, power drive circuit and other components can be used to control the system. So it is not easy to use stepper motor, it involves the mechanical, electrical, electronics and computer and many other professional knowledge. Stepper motor, which is controlled by the DC pulse, generally speaking, the power is relatively small, for the accuracy of the requirements of the open-loop automatic control system, it has a drawback is easy to get out of step. Servo motor is divided into two categories of AC and DC, power relative to teach large, high precision; the main difference between the two is to see whether the end of the motor photoelectric encoder. The servo motor relies on the photoelectric encoder to feed back the position signal. By the way, the closed-loop control can be divided into half-closed and closed-loop, but the semi-closed-loop device is commonly used, and only a very precise device is used.