How to tell if a stepper motor driver is good or bad

Without connecting any equipment and wires, put the stepper motor.

Each wire is separated, do not touch the line, rotate the shaft by hand, a good motor, it should only need a certain force, it can rotate smoothly, there is no card in the middle, if there is a certain position in the middle of the card or completely unable to rotate, indicating that the motor has been broken, it may be that the bearing is displaced, the internal rotor and stator are worn. The cause of damage should be caused by excessive external force. A multimeter can be used.

The amount of impedance of two "adjacent" phases.

should be equal to the coil impedance given by the product.

If the equipment detects idling, it should be able to reach the specified speed, and the noise should be stable at the general speed. Otherwise, load testing is required. The specific test parameters need to be combined with the load torque and the torque of the motor.

The larger the motor, the greater the force required to twist, and the general stepper motor cannot be twisted by manpower at all. (The more threads you twist together, the more force is required.) If it doesn't work, it means that the coil is broken.

On the equipment detection, when idling, it should be able to reach the specified speed, and at the general speed, the noise should be stable. Otherwise, load testing is required. The specific test parameters need to be combined with the load torque and the torque of the motor.

Second, the wires are screwed together, the larger the motor, the greater the force required to twist, and the general stepper motor cannot be twisted by manpower at all. (The more threads you twist together, the more force is required.) If it doesn't work, it means that the coil is broken.

For synchronous motors.

In addition to the above methods, it is necessary to carefully observe the rotor, which cannot be ignored. If there is a gap in the rotor, it is not bad and small, the nails can not be embedded, and the power performance is at least 8% off, at this time, it is very easy to lose the possibility of step, it is recommended to replace it; And servo motors.

Its Achilles' heel is that it cannot be knocked when loading and unloading, and it is easy to put the encoder inside.

Vibration breaks. The probability of the power coil of the servo motor burning out is quite low, the encoder and joint damage are common, and the common servo failure is the encoder failure.

First power on the drive, make sure the power indicator is normal? If it's not normal, the drive is bad; If the power indicator is normal, unplug the enable signal, twist the motor shaft by hand, whether the motor is forced, if not, the driver is bad; If the motor is forced, send a control pulse to the driver, whether the motor is running, if it is running, the driver is good; If it does not turn, determine whether the control signal level matches or not, if it does, the driver is bad; If it is not matched, adjust the control signal level, whether the motor is running or not, if it is running, the drive is good, otherwise it is bad.

The drive is powered on, if the power indicator is not on – the drive is broken;

Connect the motor, the driver is powered on, and the fault indicator light is on - the driver is broken;

Connect the motor, the driver is powered on, the motor is forced, but the motor does not rotate when the control signal is sent - the drive is broken;

Without the above several cases, there should be nothing wrong with the drive itself.

Stepper motor driver subdivision is a drive control technology developed in the mid-seventies that can significantly improve the overall performance of stepper motors.

It is by controlling the current in the windings of each phase, so that they rise or fall according to a certain law, that is, a plurality of stable intermediate current states are formed between the zero current and the maximum current, and there will also be a plurality of stable intermediate states in the direction of the corresponding resultant magnetic field vector, and rotate according to the subdivision step. The amplitude of the resultant magnetic field vector determines the magnitude of the rotational moment of the stepper motor, and the direction of the resultant magnetic field vector determines the magnitude of the step angle after subdivision. The subdivision drive technology further improves the angle accuracy and running smoothness of the stepper motor.

The driver and the controller are different functions of the driver, and the controller is specially designed to send pulse signals to the driver.

A stepper motor controller has a different role than a driver.

1. The stepper motor controller is an electronic product that can send out an average pulse signal, and after the signal it sends enters the stepper motor driver, it will be converted into a strong current signal required by the stepper motor to drive the stepper motor to run.

2. Stepper motor has a wide range of applications in the control system. It can convert pulse signals into angular displacement, and can be used as electromagnetic brake wheels, electromagnetic differentials, or angular displacement generators, etc. The driver says that it receives a pulse signal, and every time it receives a pulse, the stepper motor controller will drive the motor to turn at a fixed angle, which is due to this feature, the stepper motor will be widely used in various industries.

3. The stepper motor driver is an actuator that converts electrical impulses into angular displacement. When the stepper driver receives a pulse grip signal, it drives the stepper motor to rotate at a fixed angle in the set direction (called the "step angle"), and its rotation runs step by step at a fixed angle. The angular displacement can be controlled by controlling the number of pulses, so as to achieve the purpose of accurate positioning; At the same time, the speed and acceleration of the motor can be controlled by controlling the pulse frequency, so as to achieve the purpose of speed regulation and positioning.

The principle of a stepper motor driver, powered by a unipolar DC power supply. As long as the windings of each phase of the stepper motor are energized according to the appropriate timing, the stepper motor can be made to step and rotate.

In the case of not connecting any equipment and wires, separate each line of the stepper motor, do not touch the line, rotate the shaft by hand, a good motor, it should only need a certain force, it can rotate smoothly, there is no card in the middle, if there is a certain position in the middle of the card or completely unable to rotate, indicating that the motor has been broken, it may be that the bearing is displaced, the internal rotor and stator are worn. The cause of damage should be caused by excessive external force. The impedance of the two phases "adjacent" can be measured with a multimeter, which should be equal to the coil impedance given by the product.

When the equipment detects that it is idling, it should be able to reach the specified speed, and the noise emitted should be stable at the general speed. Otherwise, load testing is required. The specific test parameters need to be combined with the load torque and the torque of the motor.

The wires are screwed together, the larger the electric shortage machine, the greater the force required to twist, and the general stepper motor cannot be twisted by manpower at all. (The more threads you twist together, the more force is required.) If it doesn't work, it means that the coil is broken.

Differences:1The speed requirements are different. The stepping is suitable for low speed applications and small speed adjustment ranges. When the servo motor can control the speed, it is large.

2.Controllable reliability is different. Because the servo motor has a feedback signal, it is possible to achieve highly reliable control in the control system.

3.The output torque requirements are different. At present, at home and abroad, the maximum series of stepper motors is 130 frames. The maximum output static torque is 50 N. Rice. The servo motor can have more than 180 boxes and 60 Nm. The output torque above meters is optional.

First, the number of transistors is different.

1. The unipolar drive circuit uses four transistors to drive two sets of phases of a stepper motor.

2. The bipolar stepper motor uses eight transistors to drive two sets of phases.

Bipolar stepper motor drive circuits have twice as many transistors as unipolar drive circuits, with four low-end transistors typically driven directly by the microcontroller and higher-end transistors requiring a more expensive up-end drive circuit.

Second, the connection is different.

1. The motor structure of the unipolar drive circuit contains two sets of coils with intermediate taps, and the whole motor has a total of six wires connected to the outside world.

2. The bipolar drive circuit can drive the four-wire or six-wire stepper motor at the same time, although the four-wire motor can only use the bipolar drive circuit, it can greatly reduce the cost of mass production applications.

Third, the voltage is different.

1. The transistor of the bipolar drive circuit only needs to withstand the motor voltage.

2. The unipolar drive circuit needs a clamping circuit to drive.