What is the specific principle of adding two resistors and two transistors in the resistance buck circuit in the figure?

These two transistors seem to be 400V-resistant tubes. The purpose here is first-level buck and first-level voltage regulation. One piece of this triode, used in 220Vac circuit, has the risk of withstand voltage.

    When the circuit satisfies several conditions, it can be used - 0 load, two 47K has a certain risk. At full load, two 56Ks have a greater risk of breakdown (two 15Ks in series or three in series with appropriate resistance) should be used. The specific safety range needs to be calculated.

This is not a resistance-capacitance buck. The resistance-capacitance buck capacitor is connected inside. The feeling is to use a triode to build a high-voltage LDO.

Two and 56K share a part of the power, and then use two transistors to share the power and share 5V. Why do you use a transistor to share the power without a resistor? Because the transistor has a current expansion effect, the load capacity of the output 5V voltage is enhanced .