Switching converter and switching power supply concepts

The power supply is the core of all equipment, and its importance is like the heart of the human body, but the power supply has many forms. The parameters of the power supply generally include voltage, power, load current, noise, and changes in various parameters under dynamic load conditions

, etc. Under the same parameter, there are indicators such as weight, volume, efficiency, and reliability. Therefore, there are extremely many forms of power supply. Ordinary electricity (mains electricity) needs to be converted before it can become what our various devices need, for example: AC becomes DC, high voltage becomes low voltage, low frequency becomes high frequency, etc. In fact, the conversion process is that we obtain the power form we need through certain means.

According to the industry's name, AC-DC (AC converted to DC, AC is AC, DC is DC) is called rectification, including rectification and offline conversion; DC-AC is called inversion, AC-AC is called AC-AC frequency conversion (accompanied by voltage conversion), and DC-DC is called DC-DC conversion. We can use a variety of methods to achieve the purpose of conversion. Currently, semiconductor devices are mainly used to achieve conversion. Generally speaking, any circuit that uses semiconductor power devices as switches to convert one form of power into another is called a switching converter circuit. As long as the automatic closed-loop stable output and protection function are used during conversion, it is called a switching power supply. The main component of a switching power supply is a DC-DC converter, which is the core of the conversion and is related to the frequency. The frequency achieved by DC-DC conversion is the highest.

We often hear about offline switching converters. In fact, it is AC-DC conversion. Some people also call it a switching rectifier, but it is not a simple rectification, but a DC-DC conversion after rectification. Therefore, offline does not mean that the converter has no relationship with the mains line, but it is called offline because of the high-frequency transformer isolation in the converter.