As a special type of motor used for control, stepper motors cannot be directly connected to DC or AC power supplies and must use a dedicated drive power supply (stepper motor driver). Before the development of microelectronics technology, especially computer technology, the controller (pulse signal generator) was entirely implemented in hardware. The control system used individual components or integrated circuits to form the control loop. This was not only complex to debug and install, consuming a large number of components, but also required a complete redesign of the circuit if the control scheme was changed after it was finalized. This necessitated the development of different drivers for different motors, resulting in high development difficulty and cost, and significant control challenges, thus limiting the widespread adoption of stepper motors.
Because a stepper motor is a device that converts electrical pulses into discrete mechanical motion, it possesses excellent data control characteristics. Therefore, computers have become an ideal driver for stepper motors. With the development of microelectronics and computer technology, a hardware-software integrated control method has become mainstream, where control pulses are generated by a program to drive the hardware circuit. Microcontrollers control stepper motors through software, better unlocking the motor's potential. Therefore, using microcontrollers to control stepper motors has become an inevitable trend and aligns with the digital age.
1. Determine the application scenario
First, you need to determine the application scenario for the stepper motor. Different application scenarios require different stepper motors. For example, if you need to control a large load, you need to choose a stepper motor with higher torque; if you need to control a high speed, you need to choose a stepper motor with higher speed. Therefore, you need to clarify your application scenario before selecting a stepper motor.
2. Determine the type of stepper motor.
Stepper motors can be divided into two types: single-phase stepper motors and two-phase stepper motors. A single-phase stepper motor has only one solenoid coil, making it simple to control, but it has lower torque; a two-phase stepper motor has two solenoid coils, resulting in higher torque, but its control is more complex. Therefore, before selecting a stepper motor, you need to determine which type you require.
3. Determine the step angle of the stepper motor.
Step angle refers to the angle of rotation of a stepper motor in each revolution. A smaller step angle results in higher control precision but slower speed; a larger step angle results in faster speed but lower control precision. Therefore, before selecting a stepper motor, it's necessary to determine the required step angle.
4. Determine the driving method for the stepper motor.
There are two types of stepper motor driving methods: full-step drive and micro-step drive. Full-step drive applies current directly to the motor, causing it to rotate at a single step angle. Micro-step drive divides the current into multiple smaller currents, causing the motor to rotate at tiny step angles. Micro-step drive improves the control precision of the stepper motor, but requires more complex drive circuitry. Therefore, before selecting a stepper motor, it's necessary to determine which type of drive you require.
5. Determine the voltage and current of the stepper motor.
The voltage and current of a stepper motor are crucial parameters affecting its performance. Higher voltage results in faster motor speeds, but requires a higher voltage drive circuit; higher current results in greater torque, but requires a larger current drive circuit. Therefore, before selecting a stepper motor, it's essential to determine the required voltage and current.
6. Determine the size and weight of the stepper motor.
The size and weight of the stepper motor are also factors to consider. Smaller stepper motors are easier to install in confined spaces; lighter stepper motors reduce the load on the equipment. Therefore, before selecting a stepper motor, you need to determine what size and weight you require.
In summary, choosing a stepper motor requires considering multiple factors, including the application scenario, the type of stepper motor, the step angle, the drive method, voltage and current, size, and weight. Only by selecting a stepper motor that suits your specific needs can you maximize its performance.
