Stepper motor many friends and PLC automation control in the practitioners know stepper motor, but there are also some PLC introductory students don't know why to want to add a step stepper motor drives, rather like general motors directly inserted into the power supply will be able to apply, step drive belt we know today. Stepping drive circular allocator is part can be divided into two parts, the other part is power amplifier. Circular allocator: if you receive three kinds of signal is respectively: the pulse signal, the direction of signal and off-line signal. Then the pulse signal distribution, to control the corresponding transistor power amplifier conduction, and then make the stepping motor coil electricity. From here we can see, the stepping motor to operate so must input pulse, if no pulse, stepper motor is fixed, so we need a driver for stepping motor in the winding electricity. Direction: to control AB power phase sequence, A minusB clockwise, B -Counterclockwise offline signals: A suspension of the stepper motor, AB coil electricity, A phase to the function of electricity let to the locked rotor, the rotor can't move, needs to strike at the rotor, demand for offline signals, make AB thoroughly power phase winding, rotor in A comfortable rolling condition. Stepper motor, stepper drives, and cohesion between PLC: stepper driver must first external 24 ~ 28 v dc power supply, one end to the stepper motor, the other end of the signal as the input signal is also control, step motor under external structure is to choose the photoelectric signal block, for example: PLC pulse signal to drive the internal, we only demand for PLC pulse Y0 constantly connected with the globe will be able to happen. When Y0 conduction of electric current to flow from the CP + inside, through the current limiting resistor, diode, through the CP - again, and then through the COM port back to the power of the negative side, thus form a loop. So the light emitting diode conduction, the transistor will be conducting a high level 1 occurs, if will occur as a low level 0. So when Y0 constantly connected and the globe, and by this circuit can send pulse from the external device in the drive. Then circular distributor received the pulse, the pulse signal distribution. Manipulation of the stepper motor windings of electrical. So the stepper motor in rotating time must have a pulse, if no pulse, the stepper motor is in suspended status. The same goes for the direction of signal and decoupling signal. Stepping drive about segmentation equipment step by step the set what is subdivided about the segment? Stepper motor control precision in order to progress, now stepping drive has the function of the segment, the so-called segment, is the step by using the method of drive circuit elongation decreases. For example the stepper driver set to 5 segments, assuming that the original step away from the Angle of 1. 8°Then set it to 5 after segmentation, step Angle is zero. 36°。 Also said is, step to walk the original set to segment after five steps ahead of demand. Set the segment to pay attention to matters: 1, the general situation, fine fraction can't set too much, because in the case of control pulse frequency constant, segmentation, the greater the motor rotate speed is slow, and the output of the motor torque. 2, driving a stepper motor pulse frequency can not too high, generally no more than 2 KHZ, otherwise the motor output torque decrease rapidly.
