Why is the first step always backward when the stepper motor is powered on, and the first step is fo

Generally, when the power is not on, the stepper motor is relaxed, not necessarily at which angle. The starting position after powering on is set by the software and hardware in the controller, of course, it cannot be guaranteed to be exactly the same as the original stop angle. So, when you first power it up, you always move it.

But this "move" is not always a "backstep". The "always backwards" you came across was a coincidence.

If the software is well designed, this phenomenon can be eliminated. The method is that before each power failure, the software records the current angle (phase) and saves it in "nonvolatile memory" (such as EEPROM), and reads the last saved phase when it is just powered on, and gives the initial driving electrical signal accordingly.

In this way, as long as there is no external force to toggle the angle of the motor during the power failure, it will not "move" when the power is turned on.

The main reasons: 1. The stepper motor is driven by the stepper driver, and the stepper driver is driven by the HZ waveform emitted by the single-chip microcomputer or PLC.

2. The waveform sent by PLC or single-chip microcomputer is not correct, and it may be a program (broken wave and lost wave).

3. There is a problem with the stepper driver or stepper motor (out of step).

The motor itself is a permanent magnet, and the electromagnetic force after the motor is powered on allows it to return to the nearest basic step position. This is possible both before and after.

Because the driver is DSP module, this is an inherent characteristic of digital stepper motor drivers. Normal.

The stepper motor sometimes does not return to its original position, and what is the reason for going forward a little after the shutdown is restarted.

More or less this phenomenon occurs, this is because the operating principle of the stepper motor is controlled by pulse signals. When the motor receives the pulse signal, it will rotate according to the number and direction of the pulses, and the angle of each rotation is fixed. However, sometimes due to mechanical problems, the motor may get stuck or blocked, making it impossible to return to its original position.

When the shutdown is restarted, the motor will continue to receive the previous pulse signal, but at this time the motor can no longer return to its original position, and can only continue to rotate from the previous position. In this case, it is most likely a problem with the mechanical equipment, and it is necessary to check whether the motor is hindered or if there are parts that cannot operate normally.

Dear I am happy to answer for you: Why is the bush buried stepper motor in place and still going Answer: Dear, you can consider whether it is a problem of phase order, it may be poor contact.

Or maybe there's something wrong with the drive itself. Your phenomenon is not like a disturbance, but if it is interfered, it is just that the speed is not normal. If it is controlled by a single-chip microcomputer, it is possible that the program of phase sequence distribution is not well written!

When starting or accelerating, if the pulse changes too fast, the rotor cannot follow the change of the electrical signal due to inertia, resulting in stalled or out-of-step, and when stopping or decelerating, overstepping may occur due to the same reason. In order to prevent stalling, out-of-step and overstepping, and increase the working frequency, it is necessary to control the speed of the stepper motor. The rotational speed of the stepper motor depends on the pulse frequency, the number of rotor teeth, and the number of beats.

Its angular velocity is proportional to the pulse frequency and is synchronized with the pulse in time. Therefore, when the number of rotor teeth and the number of running beats are constant, the required speed can be obtained by controlling the pulse frequency. Since the stepper motor is started with the help of its synchronous torque, in order not to lose step, the starting frequency is not high.