Stepper Motor Basics Pegasus Web Server （步进电机基本飞马Web服务器）.pdfVIP

Stepper Motor and Its Driver Reference of EAS 5407 Mechatronics Design Project Spring 2003 I. Stepper Motor Basics A stepper motor is an electro mechanical device, which converts electrical pulses into discrete mechanical movements. The shaft or spindle of a stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence. The sequence of the applied pulses is directly related to the direction of motor shafts rotation. The speed of the motor shafts rotation is directly related to the frequency of the input pulses and the length of rotation of input pulses applied. 1. Stepper Motor Advantages and Disadvantages Advantages 1. The rotation angle of the motor is proportional to the input pulse. 2. The motor has full torque at stand still (if the winding are energized) 3. Precise positioning and repeatability of movement since good stepper motor s have an accuracy of 3 –5% of a step and this error is non cumulative from one step to the next. 4. Excellent response to starting stopping reversing. 5. Very reliable since there are no contact brushes in the motor. Therefore the life to the motor is simply dependant on the life of the bearing. 6. The motors response to digital input pulses provides open-loop control, making the motor simpler and less costly to control. 7. It is possible to achieve very low speed synchronous rotation with a load that is directly coupled to the shaft. 8. A wide range of rotational speed is proportional to the frequency of the input pulses. Disadvantages 1. Resonance can occur if not properly controlled. 2. Not easy to operate at extremely high speeds. 2. Open Loop Operation One of the most significant advantages of a stepper motor is its ability to be acc