Answer: D. Choose a suitable pulse distributor.
Answer analysis:
When discussing the main issues of using microcomputers to control stepper motors, we can examine each option one by one:
A. Generating pulse trains by software methods: This is a basic and important issue in controlling stepper motors. The working principle of stepper motors is to rotate step by step by receiving a series of pulse signals.
Therefore, how to accurately generate these pulse signals through software is the key to controlling stepper motors.
This includes determining the frequency, width, and number of pulses to ensure that the motor can operate as expected.
B. Direction control: Direction control is also a core issue in stepper motor control. Stepper motors can rotate clockwise or counterclockwise, depending on the order of input pulses. Therefore, how to control the direction of the motor by controlling the input order of pulses is an issue that must be considered when using microcomputers to control stepper motors.
C. Control program design: Control program design is another key issue in controlling stepper motors. This includes how to write programs to generate pulses, control direction, adjust speed, etc. An efficient and stable control program is the key to ensuring the normal operation of stepper motors.
D. Choose a suitable pulse distributor: Although the pulse distributor plays an important role in the stepper motor control system and is responsible for converting the control signal into the pulse sequence required by the stepper motor, it is not the main problem of using a microcomputer to control the stepper motor.
In modern microcomputer control systems, the function of pulse distribution can often be implemented by software or simplified by an integrated control chip. Therefore, choosing a pulse distributor is more of a technical selection or hardware design issue rather than a major issue in controlling the stepper motor.
In summary, the option that is not the main problem of using a microcomputer to control the stepper motor is D: "Choose a suitable pulse distributor".