The switching regulator keeps the output voltage stable by controlling the transistor to switch between ON state and OFF state (switching action). When the transistor is completely ON, Vce (sat) <=1V, and the collector-emitter voltage Vce of the transistor is very small. At this time, even if the collector current Io flows through the transistor, it will not cause excessive power loss.

In addition, when the switching regulator is in the OFF state, there is no collector current, and of course, there is no power loss. This is the main reason for the small power loss of the switching regulator.

Switching regulators are supplied on demand and non-series regulators are always supplied.

The current output of the switching circuit is not DC, and it needs to be connected to the rectified smooth current behind it to convert the pulsating current into DC current