The rectifier smoothing circuit of the switching regulator has capacitor input type and choke input type, which need to be flexibly applied according to the circuit mode of the switching regulator.

The step-down chopper switching regulator uses choke input type, and the boost chopper and reverse chopper switching regulator uses capacitor input type.

Supply on demand (adjusting the switching ratio of the transistor) to obtain arbitrary DC and a stable output voltage.

A switching regulator that normally feeds alternating current directly into a power supply without passing through a power transformer is called a linearly adjustable power supply or off-line converter.

Linear switching regulator structure, a. self-excitation b. Separate excitation.

Self-excited, continuous oscillation generated by switching transistor and output transformer. The circuit structure is simple, only suitable for low power output equipment.

Another type of excitation, the control circuit has an oscillator, the circuit structure is complex but the characteristics are good, suitable for high-power equipment.

The linear switching regulator includes an output transformer, and the input and output must be isolated to avoid induced voltage.

In general, the switching frequency of the switching transistor is set outside the human hearing frequency, which is more than 20KHz.