motor controller Electric pulse transformation
The stepper motor driver is an actuator that converts electrical pulses into angular displacements. When the stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle in the set direction (called "step Angle "), its rotation is a step by step to run a fixed angle; can control the number of pulses to control the amount of 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 speed and positioning purposes. In the case of
Stepper motor drive principle, the use of unipolar DC power supply. As long as the stepper motor phase winding in accordance with the appropriate timing power, you can make stepper motor step rotation. Four-phase stepper motor step diagram at the beginning, the switch SB connected to the power supply, SA, SC, SD off, B phase magnetic pole and rotor 0, 3 teeth aligned at the same time, the rotor 1 and 4 teeth and C, D-phase winding pole produces misaligned teeth, 2,5 teeth and D, A-phase winding magnetic pole to produce staggered teeth. When the switch SC is connected to the power supply, when the SB, SA and SD are disconnected, the rotor is rotated due to the magnetic field lines of the C-phase winding and the magnetic field lines between the 1 and 4 teeth, and the poles of the 1, 4 and C-phase windings are aligned The And 0, 3 teeth and A, B phase winding produce staggered teeth, 2,5 teeth and A, D phase winding magnetic pole to produce staggered teeth. And so on, A, B, C, D four-phase winding power supply, the rotor will be along the A, B, C, D direction of rotation.
Four-phase stepper motor in accordance with the different order of power can be divided into single four beat, double four beat, eight beat three kinds of work. Single four-shot and double four-step pitch equal, but a single four-shot rotation torque is small. Eight steps of the work of the step angle is a single four and double four shot half, so the eight-shot work can not only maintain a high torque and can improve the control accuracy. Single four-shot, double-four-beat and eight-shot mode of operation power supply timing and waveform respectively Stepping motor operation to have an electronic device to drive, this device is the stepper motor driver, it will control the system issued by the pulse signal amplification To drive the stepper motor. The speed of the stepper motor is proportional to the frequency of the pulse signal. The frequency of the stepping pulse signal can control the speed of the motor and control the number of stepping pulses to precisely locate the motor. Stepper motor drive control system consists of the following three parts: step controller, drive and stepper motor.
The step controller is implemented by the microcontroller, which drives the pulses output by the microcontroller to drive the stepper motor. The general block diagram of the single-chip control stepper motor is shown in the figure. Can not use DC or AC frequency direct drive stepper motor, you must use a dedicated stepper motor drive circuit, or with a separate component of the dedicated circuit. The The drive is equivalent to the combination of the switch unit. Through the host computer pulse signal sequence to the motor phase sequence power to make the motor rotation.