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e motor output torque continue to decay . The dynamic torque motor run time depends on the motor phase current at rated current and voltage, phase current increases, the motor output torque at low speeds, the greater the higher the voltage , the greater the torque at high speed .

                             
Indicates that the voltage or current value becomes large, the torque trend . Also, please note that the same motor torque-frequency characteristic curve under a different drive, there will be differences in the representation , so the selection should be left margin .

Motor resonance point : stepper motor resonance region are relatively fixed , 2,4 -phase hybrid stepping motor resonance region is generally between 180 ~ 250pps ( step angle of 1.8 degrees ) . The higher the motor drive voltage , motor current increases, the lighter the load , the motor size is smaller, the resonance offset upward . To make the motor output torque, without losing step and make the system noise reduction , generally operating point should shift more resonance region . Note: The breakdown will change the position of the resonance region .

Lost step ( step- ) : the controller to the motor made a n pulses , the stepper motor does not turn the n-th step angle . Generally when the motor torque is too small, too large acceleration , high speed , friction, and so will lose steps uneven phenomenon .

Stepper motor type: stepper motors include stepping motor response (VR), permanent magnet stepper motor (PM), hybrid stepper motors (HB) and so on.
Permanent magnet stepper motor is generally two -phase, torque and smaller, step angle of 7.5 degrees or 15 degrees ;

Reaction is generally three-phase stepper motor can achieve high torque output , step angle of 1.5 degrees , but the noise and vibration are great. Reaction stepping motor rotor magnetic circuits made of a soft magnetic material , multi-phase exciting winding on the stator , the use of magnetic torque generated by changes in conductivity ;

Hybrid stepper motor is a permanent magnet and integrated reactive advantages designed stepper motor. It is divided into two phases and five phases : two -phase step angle of 1.8 degrees, while the five -phase step angle of 0.72 degrees . Currently, the two -phase hybrid stepping motor most commonly used.

The polarity of the stepper motor : stepping motor of the motor and the unipolar bipolar motor . Figure 2.2 (a) shows a bipolar motor , a current flows in the coil 2 Timing of AA (-) → BB (-) → A (-) A → B (-) B; the unipolar motor coil the current flow direction is fixed , as shown in 2.2 (b) shows the timing of the energization VA → VC → VB → VD. Unipolar motor bipolar drive motor driver than simple, unipolar motor output torque is small.

Stepper motor control can be used as a special motor , using its no accumulation of error ( accuracy of 100% ) , which is widely used in various open-loop control .

1 General stepper motor step angle accuracy of 3 - 5% , and not cumulative .

2 stepper motor surface maximum temperature allowed . First, the stepper motor causes the motor temperature is too high magnetic demagnetization , resulting in loss of torque down even further , so the motor surface temperature should be the maxi本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。