Does a Stepper Motor Need a Stepper Motor Driver?

The answer is yes, the stepper motor must use a drive in order to work properly. Then why does a stepper motor need a stepper motor driver?

The first reason is that the stepper motor needs a driver to regulate voltage and current.

First of all, let's understand the working principle and control of the stepper motor.

The basic working principle of the stepper motor is: energizing one or more stator phases, the current passing through the coil will generate a magnetic field, and the rotor will be aligned with the magnetic field; Applying voltage to different phases in turn, the rotor will rotate at a specific Angle and eventually reach the desired position.

The control of the stepper motor is that the motor coils need to be energized in a specific order to generate a magnetic field with which the rotor will be aligned. There are several types of devices that can provide the necessary voltage to the coil to allow the motor to operate properly (starting with those closer to the motor).

Transistor bridge: A device that physically controls the electrical connections of motor coils. The transistor can be thought of as an electronic circuit breaker. It closes when the coil is connected to the power supply, and the current passes through the coil. Each motor phase requires a transistor bridge.

Predriver: A device that controls transistor activation, which is controlled by the MCU to provide the required voltage and current.

MCU: A microcontroller unit, usually programmed by the motor user, that generates a specific signal for the pre-driver to obtain the desired motor behavior.

It can be seen that the correct voltage and current is crucial to the work of the motor, and the microcontroller is also essential to the motor, but the working voltage of many stepper motors is higher than the working voltage limit of the microcontroller. In addition, the current required by the stepper motor is also greater than the maximum current that a microcontroller or a microprocessor can handle.

If you want to control a stepper motor using a micro-controller, you have to deal with voltage and current first. This is why a driver is used, because an important feature of a stepper motor driver is that it can control the voltage at both ends of the winding and the current flowing through the winding, and it’s features are :

· Voltage control function : the driver can adjust the voltage on the winding, the torque and step speed generated depends only on the motor and load characteristics.

· Current control drivers are more advanced because they can regulate the current flowing through the active coil for better control of the torque generated and thus better control of the dynamic behavior of the overall system.

Another reason is that the stepper motor requires a driver to control the speed

The speed of the stepper motor is controlled by the electric pulse, but the frequency of the electric pulse is not the only factor affecting the speed of the stepper motor. The driver is the main part of controlling the stepper motor, and you can achieve more accurate control effect by adjusting the parameters of the driver. The specific principles are as follows:

1. Current control: the motor speed is proportional to the current, because the motor of the stepper motor needs to consume a certain amount of current to work normally, therefore, the driver needs to control the speed of the stepper motor by controlling the current.

2. Speed loop control: The speed loop control in the driver can adjust the output pulse frequency according to the speed of the motor, so as to realize the control of the speed of the stepper motor.

3. Acceleration control: The acceleration control in the driver can set different acceleration according to the motion requirements, so as to achieve a smoother and more accurate motion effect.

You can control the stepper motor speed by adjusting the drive parameters

The driver usually has several adjustable parameters, which can be adjusted to control the speed, acceleration and deceleration of the stepper motor. These parameters include but are not limited to the following:

1. Step motor phase current

Adjusting the phase current of the stepper motor can control the speed and torque of the stepper motor, and the specific value should be adjusted according to the motor and mechanical structure, work load and other actual conditions.

2. Break down steps

Subdividing the number of steps means that each step pulse is subdivided into several micro steps, which can control the stepper motor rotation with a higher resolution, so as to obtain a more fine motion effect. However, subdividing the number of steps reduces the maximum speed of the stepper motor.

3. Maximum speed

Maximum speed refers to the maximum rotation speed of the stepper motor, which can be adjusted by modifying parameters in the driver.

4. Acceleration and deceleration

Acceleration and deceleration is to control the acceleration and deceleration of the stepper motor when it starts and stops, and adjusting these parameters can make the stepper motor movement more stable.

In addition to general purpose drivers, in order to obtain higher control accuracy and motion stability, high precision drivers can also be used for control. High precision drives usually have the characteristics of higher subdivision steps, higher speed, and higher accuracy. However, high precision drives are relatively expensive.

Of course, there are many reasons why stepper motors need drivers. For example, stepper motor drivers can provide higher output power. The output power of the motor is related to its driver, and the driver can provide a higher output power to meet the needs of the motor.

Again, the driver of the stepper motor can provide accurate frequency control. Stepper motors can provide precise Angle control, but without accurate frequency control, stepper motors cannot operate properly.

In short, the stepper motor must use a driver in order to work properly. Stepper motor drivers can provide higher output power, more accurate output current voltage, frequency control, more precise position control, and higher efficiency. Therefore, the stepper motor must use a driver in order to work properly.

Article source: https://article-realm.com/article/Product-Reviews/48299-Does-a-Stepper-Motor-Need-a-Stepper-Motor-Driver.html