1. Noise generated by switching power supply during use. Switching power supply will change the current, resistance and other factors in the process of use, resulting in changes in the internal situation of switching power supply, which generally has the characteristics of fast and rapid, so it is easy to produce noise and affect the surrounding environment.
2. Noise generated by internal component loss of switching power supply. Due to frequent operation, the internal components of switching power supply have certain losses, so when the internal components of switching power supply have losses, it will directly cause noise.
3. Noise caused by natural factors. Current has strong physical properties and is easily influenced by external natural factors during operation. For example, in the process of using switching power supply in thunderstorm days, it is easy to produce a lot of noise.
4. Noise caused by circuit reasons. Switching power supply controls the whole circuit system, and the circuit system will also react to the switching power supply under certain conditions, which will have an impact on the switching power supply. In the actual operation process, the noise of switching power supply is often caused by the problems of circuit system.