Pwm motor speed control principle, single chip PWM motor speed control program
For the motor speed adjustment, we use pulse width modulation (PWM) method. When controlling the motor, the power supply does not continuously supply power to the motor, but provides power in the form of square wave pulses at a specific frequency. Square wave signals with different duty cycles can regulate the motor. This is because the motor is actually a large inductor, which has the ability to block the input current and voltage abrupt change, so the pulse input signal is evenly distributed to the action time. In this way, changing the duty ratio of the input square wave on the initial energy terminals PE2 and PD5 can change the magnitude of the voltage applied across the motor, thereby changing the rotational speed.
PWM control technology has become the most widely used control method of power electronics technology because of its simple control, flexibility and good dynamic response. It is also a research hotspot. Since the development of science and technology today has no boundaries between disciplines, combining modern control theory or implementing resonant-free switching technology will become one of the main directions for the development of PWM control technology. It modulates the bias of the transistor base or the gate of the MOS transistor according to the change of the corresponding load to realize the change of the on-time of the transistor or the MOS transistor, thereby realizing the change of the output of the switching regulator power supply. This way, the output voltage of the power supply can be kept constant when the operating conditions change. It is a very effective technique for controlling the analog circuit by using the digital signal of the microprocessor.
