First of all, the switching power supply is a power supply. It is a switching device. You don't know how to compare it with other switches we usually say. Of course, the function of the switching device is roughly the same as that of a general switch. The switching power supply can be divided into an AC input switching power supply and a DC input switching power supply. We usually refer to the switching input power of AC input, which turns the AC into DC input power frequency AC, and becomes DC through the rectifier circuit. After high frequency inverter, it gets high frequency AC, transforms through the transformer, rectifies, and outputs pulsating DC. The DC output is small through the filter output. This is the principle of a general switching power supply.