And the advantage of driving method and requirements of stepping motor and defect

Driving method

Stepper motor directly from the power frequency AC or DC power supply to work, butmust use special stepper motor driver, which is composed of a pulse generating and controlling unit, a power driving unit, a protection unit etc.. The drive unit and the step motor direct coupling, power interface can also be understood as a stepping motormicrocomputer controller.

The driving requirements

1, has high power and efficiency of rhyme.

Stepper motor driver, it is the control system sends out the pulse signal into angular displacement, the stepper motor control system or said: each send a pulse signal,through the driver makes the stepper motor to rotate a step angle. That is to say the stepper motor speed and pulse frequency is proportional to. So the control of stepperpulse frequency, can accurate speed control of motor; control the number of step pulse, can accurate positioning of the motor. There are a lot of stepper motor drive,select the drive should be based on the actual power requirements reasonable.

2, to provide fast current rise and fall speed, so that the current waveform as close as possible to the rectangle.

For the cut-off period has release current loop, in order to reduce the winding back EMF, accelerated current decay.

Advantages and disadvantages of

Advantage

1, because there is no brush, the reliability is high, so the service life of the motordepends only on the bearing life;

2, the motor rotation angle is proportional to the number of pulses;

3, because each precision in three percent to five percent, and the error accumulationwill not step to the next repetition has a good position accuracy and movement;

4, the motor stops with maximum torque (when winding excitation);

5, because the speed is proportional to the pulse frequency, so it has wide speed range.

6, good start stop and reverse response;

7, only the load directly connected to the rotating shaft of the motor can also beextremely low speed synchronous rotation;

In response to the 8, the motor only by digital input pulse is determined, thus we can use open-loop control, which makes the structure of the motor can be relatively simple and cost control;

Defect

1, it is difficult to operate at high speed;

2, if not properly controlled easy resonance;

3, over load may damage the synchronization, high speed operation will be issued when the vibration and noise.

4, it is difficult to obtain a large torque;

In 5, the volume and the weight has no advantage, low energy utilization rate;