What is the principle of PWM technology?

[Kendra]

The basic principle of PWM is: the control method involves managing the switching of inverter circuit devices to generate a series of equal-amplitude pulses at the output. These pulses are used to replace sine waves or other desired waveforms. In other words, multiple pulses are generated within half a cycle of the output waveform, making the equivalent voltage of these pulses resemble a sine wave, resulting in a smooth output with minimal low-order harmonics. By modulating the width of these pulses according to specific rules, both the output voltage magnitude and frequency of the inverter circuit can be adjusted. Below is a detailed introduction to PWM: 1. Concept of PWM: PWM stands for Pulse Width Modulation, which is an analog control method. It modulates the bias of the transistor base or MOS gate according to changes in the corresponding load, thereby altering the conduction time of the transistor or MOS tube, thus changing the output of the switching power supply. 2. Advantages of PWM: The signals from the processor to the controlled system remain in digital form, eliminating the need for digital-to-analog conversion. This is because keeping the signal in digital form minimizes the impact of noise, enhancing noise resistance.