Drive control system composition of the stepper motor
The use and control of the stepper motor must be a control system composed of ring pulse, power amplification, etc. The block diagram is as follows: The use and control of the stepper motor must be a control system composed of ring pulse, power amplification, etc.
The pulse signal is generally generated by the MCU or CPU, and the duty cycle of the general pulse signal is about 0.3-0.4, and the higher the motor speed, the greater the duty cycle.
2. Signal distribution
The induction type stepping motor is mainly based on two and four phase motors, two phase motor working mode has two phase four beats and two phase eight beats, the specific distribution is as follows: two phase four beats, step Angle is 1.8 degrees; Two phase eight beats, the step Angle is 0.9 degrees. The four-phase motor also has two working modes, the four-phase four-beat is AB-BC-CD-DA-AB, and the step Angle is 1.8 degrees; Four phases and eight beats are AB-B-BC-C-CD-AB,(step Angle is 0.9 degrees).
3, power amplification
Power amplification is the most important part of the drive system. The torque of a stepper motor at a given speed depends on its dynamic average current rather than its static current (and the current on the sample is static current). The greater the average current, the greater the motor torque, and to achieve the average current, it is necessary to drive
The system tries to overcome the back potential of the motor. Therefore, different occasions to take different driving methods, so far, the driving methods are generally the following: constant voltage, constant voltage series resistance, high and low voltage drive, constant current, fine fraction, etc.
Once the stepper motor is set, its performance depends on the drive power of the motor. The higher the speed of the stepper motor, the greater the torque, the greater the current of the motor, the higher the voltage of the drive power supply.
4. Subdivide the drive
Under the condition that the step Angle of the stepper motor cannot be used, A subdivision driver can be used to drive the stepper motor. The principle of the subdivision driver is to control the operation of the stepper motor by changing the size of the adjacent (A, B) current to change the Angle of the synthetic magnetic field.
