Thursday, July 18, 2024

Introduction to the functions and troubleshooting of closed-loop stepper motor drivers


A closed-loop stepper motor driver is a motor driver that integrates multiple functions such as speed regulation, positioning, increasing output torque, and reducing mechanical noise. It is mainly used in equipment and occasions that require high-precision positioning, stability, and reliability. This article will start from the principle and function of the closed-loop stepper motor driver and introduce its characteristics and solutions to common faults in detail.

2.Characteristics of closed-loop stepper motor drivers

1.High precision: The closed-loop stepper motor driver can provide high-precision motion control and can achieve operation with small steps, with the minimum step reaching 0.001mm.

2.High speed: The maximum speed of the closed-loop stepper motor driver can generally reach 1000r/min, and its speed and torque output are related to the load and voltage of the motor.

3.Low noise: The output torque of the closed-loop stepper motor driver is stable, the operation is smooth, and the mechanical noise can be reduced.

4.Low vibration: The change of the output signal of the closed-loop stepper motor driver can make the control system respond more quickly, thereby reducing vibration and jitter and improving the control accuracy of the motor.

5.High reliability: The closed-loop stepper motor driver adopts a closed-loop control system, which can achieve precise position control and improve the reliability of the system.

3.Common faults and treatment methods

1.Emergency stop fault: When the controller stops suddenly, the motor driver will rotate too fast. The treatment method for this fault is to restart the controller for debugging and check whether the wiring of the motor driver is normal. If the wiring is confirmed to be correct and the fault still exists, the motor driver needs to be replaced.

2.Parameter setting error: When the parameters of the motor driver are set incorrectly, abnormal or unsmooth movement will occur. For this fault, the solution is to carefully check whether the equipment parameter settings are correct and make corresponding adjustments.

3.Excessive noise: When the motor is running and there is a fault of excessive noise, it is necessary to check whether the motor has foreign matter or wear and tear, and adjust and replace the parts with poor contact.

4.Unable to move: When the motor cannot move normally, it is necessary to check whether the power supply of the controller is stable, whether the control circuit is faulty, and to check and repair the problems one by one.

5.Failed to return to zero: When the motor cannot return to zero, it is necessary to check whether the connection between the motor and the sensor is normal, whether the parameter settings are correct, etc., and make corresponding adjustments.


The above is a detailed explanation of the function introduction and troubleshooting of the closed-loop stepper motor driver in this article. The closed-loop stepper motor driver has a wide range of applications, but it also has many fault phenomena. Therefore, the ability to repair and troubleshoot is also very important. Readers can have a deeper understanding of the driver through the study of this article and be able to better deal with faults.

Thursday, July 11, 2024

The difference between two-phase stepper motors and four-phase stepper motors

1.Working principle

1.Two-phase stepper motors

Two-phase stepper motors refer to motors whose drive circuits have only two inputs, each of which controls a coil. When this motor rotates, one coil is activated first to generate a magnetic field, and then the other coil is activated to generate a magnetic field, thereby driving the motor to rotate. Two-phase stepper motors are usually simpler and easier to control, but because there are only two inputs, the step angle cannot be subdivided.

2.Four-phase stepper motors

Four-phase stepper motors refer to motors whose drive circuits have four inputs, each of which controls a coil. When this motor rotates, two coils are activated first to generate a magnetic field, and then the other two coils are activated to generate a magnetic field, thereby driving the motor to rotate. Since four-phase stepper motors have four inputs, they can be divided into smaller step angles, which are more precise than two-phase stepper motors.

2.Control method

1.Two-phase stepper motors

Since two-phase stepper motors have only two control inputs, their drive circuits are relatively simple, and only one H-bridge drive circuit is needed to control their operation. Among them, the H-bridge drive circuit is a circuit used to control the direction and size of the current, which consists of four switches. The size and order of the control current can determine the direction and speed of the motor rotation.

2.Four-phase stepper motor

Since the four-phase stepper motor has four inputs, it requires a more complex control circuit. It can be driven by an external controller such as a stepper motor controller or a microcontroller. In addition, since the four-phase stepper motor can be divided into smaller step angles, the requirements for the drive circuit are higher than those for the two-phase stepper motor.

3.Output efficiency

There are also differences in output efficiency between two-phase stepper motors and four-phase stepper motors. Since the step angle of the two-phase stepper motor is relatively large and the rotation speed is relatively slow, it is suitable for low-speed and low-precision applications. The four-phase stepper motor has a finer step angle and a faster rotation speed, which is suitable for high-speed and high-precision applications.

4.Application field

Two-phase stepper motors are mainly used to control low-speed and low-precision applications. If high-speed and high-precision control is required, four-phase stepper motors are usually used. Common applications include: electronic scales, printers, scanners, etc.


Although two-phase stepper motors and four-phase stepper motors both belong to the category of stepper motors, they have some differences in working principle, control method, output efficiency, etc. Understanding these differences can help readers better choose the type of motor suitable for their application field.

Thursday, July 4, 2024

How to realize speed regulation of three-phase stepper motor

1.Overview of three-phase stepper motor

The three-phase stepper motor is an actuator that converts electrical pulse signals into angular displacement. It has the advantages of simple structure, convenient control, high precision, and no cumulative error. It is widely used in automation equipment such as CNC machine tools, robots, printers, scanners, etc.

2.Speed ​​regulation principle of three-phase stepper motor

Speed ​​regulation refers to changing the speed of the motor to meet different working requirements. The speed regulation of three-phase stepper motors is mainly achieved in the following two ways:

1.Pulse frequency speed regulation: By changing the pulse frequency input to the motor driver, the speed of the motor can be changed. The higher the pulse frequency, the faster the motor speed.

2.Current control speed regulation: By adjusting the current in the motor winding, the torque of the motor can be changed, thereby affecting the speed. The larger the current, the greater the torque and the faster the speed.

3.Speed ​​regulation method of three-phase stepper motor

1.Microstep control: By subdividing the step angle of the motor, more precise control can be achieved. For example, subdividing the step angle of 1.8 degrees into 0.9 degrees can improve control accuracy and smoothness.

2.PWM control: Use pulse width modulation (PWM) technology to adjust the current size in the motor winding to achieve smooth speed regulation.

3.Vector control: By controlling the direction and size of the motor's magnetic field, efficient and accurate speed regulation is achieved.

4.Current chopping control: By adjusting the on and off time of the current, the motor speed is controlled.

5.Hybrid control: Combine the above control methods to achieve better speed regulation performance.

4.Implementation steps of three-phase stepper motor speed regulation

1.Determine the speed regulation requirements: According to the application scenario, determine the required speed regulation range and accuracy.

2.Select a suitable driver: According to the motor parameters and speed regulation requirements, select a suitable stepper motor driver.

3.Design control circuit: Design a suitable control circuit to achieve control of the motor driver.

4.Write a control program: According to the control requirements, write a control program to achieve precise control of the motor.

5.Debug and optimize: Through actual operation, debug and optimize the control parameters to achieve the best speed regulation effect.

Three-phase stepper motor speed regulation technology has a wide range of applications and prospects in the field of automation. By choosing the appropriate speed regulation method and control strategy, the motor can be precisely controlled to meet the needs of different scenarios. With the continuous advancement of control technology, the speed regulation performance of three-phase stepper motors will be further improved, providing a stronger driving force for the development of automation equipment.

Friday, June 28, 2024

Unipolar Stepper Motor vs Bipolar Stepper Motor

1.Unipolar stepper motor


Unipolar stepper motors usually consist of two coils, each of which can control the direction of current to cause the motor to rotate. Unipolar stepper motors use a single drive signal to control the operation of two phases of the motor, so that the motor rotates at a certain step angle. The working principle is relatively simple. The phase is controlled by a single signal, so that the two coils are activated one after another to achieve rotation.

2.Advantages and Disadvantages

The advantages of unipolar stepper motors are that the control is simple and easy to implement, the cost is low, and the application fields with low precision are becoming more and more common. The disadvantage is that the torque is difficult to control and problems such as vibration and noise are prone to occur.

3.Applicable scenarios

Unipolar stepper motors are suitable for applications where torque requirements are not high, speed requirements are not high, and noise requirements are low. Such as consumer electronics, toys, clocks, etc.

2.Bipolar stepper motor


Bipolar stepper motors usually consist of four coils, each of which can make the motor rotate by adjusting the magnitude and direction of the current. The difference between a bipolar stepper motor and a unipolar stepper motor is that it requires two phases of drive signals to control. The two phases control the four coils of the motor respectively, allowing the motor to rotate at a finer step angle.

2.Advantages and Disadvantages

The advantage of the bipolar stepper motor is that it can control the step angle more accurately, the speed is relatively stable, and it has high torque. The disadvantage is that the control is more complicated and requires more complex drive circuits and control systems. Compared with unipolar stepper motors, the cost is higher.

3.Applicable scenarios

Bipolar stepper motors are suitable for scenarios that require high accuracy and speed, such as digital cameras, printers, scanners, etc.

In summary, different types of stepper motors can be selected depending on the application requirements. In practical applications, factors such as the motor's power, speed range, and load characteristics also need to be considered. Careful consideration is required when selecting a stepper motor. 


Monday, June 24, 2024

Structure and maintenance of Worm Gearbox

 1. Introduction

Worm Gearbox is a power transmission mechanism that uses a gear speed converter to reduce the number of revolutions of the motor to the desired number of revolutions and obtain a larger torque. In the mechanism used to transmit power and motion, the application range of reducers is quite wide. Its traces can be seen in the transmission systems of various machines, from ships, cars, locomotives for transportation, heavy machinery for construction, processing machinery and automated production equipment used in the machinery industry, to common household appliances and clocks in daily life. Its application ranges from large power transmission work to small loads and precise angle transmission. In industrial applications, reducers have the functions of reducing speed and increasing torque. Therefore, they are widely used in speed and torque conversion equipment.


2. Basic structure
The basic structure is mainly composed of transmission parts worm gear, shaft, bearing, box and its accessories. It can be divided into three basic structural parts: box, worm gear, bearing and shaft combination. The housing is the base of all accessories in the worm gear reducer. It is an important accessory that supports and fixes the shaft system components, ensures the correct relative position of the transmission accessories, and supports the load acting on the reducer. The main function of the worm gear is to transmit the movement and power between the two staggered shafts, and the main function of the bearing and shaft is to transmit power, operate and improve efficiency

3. Features
1. Compact mechanical structure, light volume and appearance, small and efficient;
2. Good heat exchange performance and fast heat dissipation;
3. Easy installation, flexible and light, superior performance, easy maintenance and repair;
4. Smooth operation, low noise, and durable;
5. Strong usability, high safety and reliability

4. Use and maintenance
1. Please do not apply pressure to the output components and housing of the reducer during installation. Please meet the corresponding requirements of coaxiality and verticality between the machine and the reducer when connecting.
2. The lubricating oil should be replaced after the reducer runs for 400 hours, and the subsequent oil change cycle is about 4000 hours.
3. Sufficient lubricating oil should be retained in the reducer housing and checked regularly.
4. Keep the reducer clean and remove dust and dirt in time to facilitate heat dissipation.


Sunday, June 16, 2024

What's suitable inertia ratio of the servo motor?

Inertia ratio is a crucial parameter when selecting a servo motor. It determines the motor's response speed and control accuracy. However, finding the right inertia ratio is not a simple task. We will take you to explore the appropriate range of servo motor inertia ratio and provide you with some guidelines for selection.

1.What is inertia ratio?

The inertia ratio is the ratio of the motor's rotational inertia to the load's rotational inertia. Generally, the smaller the inertia ratio, the faster the motor's response speed, but the accuracy may be reduced; the larger the inertia ratio, the higher the motor's control accuracy, but the response speed may be slower.

2.Consider load characteristics:

When selecting the inertia ratio of a servo motor, the characteristics of the load must be considered. For high-inertia loads, such as large robotic arms or mechanical transmission systems, choosing a smaller motor inertia ratio can improve the system's response speed, but still maintain sufficient control accuracy.

3.Consider acceleration and speed requirements:

Consider the acceleration and speed requirements of the system. High acceleration and speed requirements usually require a smaller inertia ratio to ensure that the motor can respond quickly to changes in the system.

4.Controller performance:

The performance of the controller is also a key factor affecting the selection of servo motors. High-performance controllers can better handle larger inertia ratios, providing higher control accuracy and stability.

5.Comprehensive considerations:

The optimal inertia ratio usually requires a balance between the motor and the load. Consider the load characteristics, acceleration, speed requirements, and controller performance, and select an inertia ratio that balances the system between speed, accuracy, and stability.


When selecting the inertia ratio of a servo motor, in-depth analysis and comprehensive considerations must be performed. Considering the load characteristics, acceleration, and speed requirements, selecting an appropriate inertia ratio can ensure that the system can operate stably and efficiently under various working conditions.

Wednesday, June 12, 2024

Technical parameters and applications of Nema17 stepper motor

NEMA17 stepper motors are widely used in various applications that require precise motion control. This motor is favored for its small size, high performance, long durability, low noise and high efficiency. The base size of NEMA17 stepper motors is 42mm, and a variety of body thickness, lead screw and screw stroke are available for customers to choose freely to meet different application requirements.

1.In terms of technical parameters, NEMA17 stepper motors usually have bipolar holding torque. For example, the M1173020 NEMA17 stepper motor provided by LAM Technologies has a bipolar holding torque of 0.28 Nm (39 oz-in), a moment of inertia of 34 g cm² (0.186 oz-in²), a length of 34 mm (1.34 inches), a weight of 240 g (8.47 oz), and a flange size of NEMA 17 inches 42.3x42.3mm (1.67 x 1.67 inches).

2.In terms of application areas, NEMA17 stepper motors are widely used in medical equipment, semiconductor processing, valve control, X-Y worktables, handheld instruments, or anywhere precise linear motion is required. These motors provide small linear motion solutions for a variety of motion control applications.

3.In terms of manufacturers, Italy's LAM Technologies is a manufacturer that has been in the market for more than 20 years and has a dominant position in the field of motion control. The NEMA17 series of products they provide include stepper motors, stepper drivers, power supplies, and kits to meet the needs of different customers.

4.In terms of other features, the HT17-278 series NEMA17-sized high-torque 2-phase hybrid stepper motors provided by AMP in the United States have high-torque design, standard NEMA 17 size, dual-axis version, UL certification of the motor, encoder options, etc.

In summary, NEMA17 stepper motors have become the first choice for many precision motion control systems due to their superior performance and wide range of applications.

Introduction to the functions and troubleshooting of closed-loop stepper motor drivers

1.Overview A closed-loop stepper motor driver is a motor driver that integrates multiple functions such as speed regulation, positioning, i...