In the half-bridge topology, two large capacitors are used to divide the voltage to obtain the midpoint voltage. What is the purpose of this design and in what occasions is it used?

普拉卡图

In the half-bridge topology, two large capacitors are used to divide the voltage to obtain the midpoint voltage. What is the purpose of this design and in what occasions is it used? [Copy link]

As shown in the picture, what does this passage in the book mean?

A half bridge with two capacitors for voltage division?

Then you get a midpoint voltage of 1/2?

That’s all the description of capacitor voltage division in the book.

I don't quite understand it, so I would like to ask for help from the experts on the forum.

I would like to know where this circuit is used.

hp880229

There are two large capacitors inside the switching power supply, which convert DC to AC for the transformer.

maychang

This circuit is used in all situations where the AC mains is rectified by bridge to obtain DC to power the half-bridge. Therefore, almost all half-bridges are used in this way.

maychang

What is the purpose of this design?

This design can avoid the DC component appearing in the load (transformer) when the two arms of the half-bridge are slightly unbalanced (for example, the turn-off time is slightly different).

吾妻思萌

This is a good question. I don’t know either. I look forward to the teacher’s answer.

led2015

Perhaps it is to reduce the harmonic noise interference in the circuit and improve the stability and reliability of the circuit.

huo_hu

I think the turn-on voltage of the MOS tube above needs to be stable at the reference point