There are two types of modern switching power supplies: one is DC switching power supply; the other is AC switching power supply. The main introduction here is only the DC switching power supply, whose function is to convert the original ecological power supply (rough power) with poor power quality, such as mains power supply or battery power supply, into a high-quality DC voltage (fine power) that meets the requirements of the equipment. 

Switching power supply is a power supply that uses modern power electronics technology to control the time ratio of switching transistors on and off to maintain a stable output voltage. Switching power supplies are generally controlled by pulse width modulation (PWM) IC and switching devices (MOSFET, BJT, etc.) The high frequency of the switching power supply is its development direction. The high frequency makes the switching power supply miniaturized and makes the switching power supply enter a wider range of applications, especially in the field of high-tech, which promotes the miniaturization of high-tech products. Lightweight.

In addition, the development and application of switching power supply are of great significance in saving energy, saving resources and protecting the environment. Especially the application in the high-tech field has promoted the development of switching power supply, which is developing towards the direction of lightness, smallness, thinness, low noise, high reliability and anti-interference with a growth rate of more than two digits every year.

Compared with switching power supply and linear power supply, the cost of both increases with the increase of output power, but the growth rate of both is different. The cost of linear power supply is higher than that of switching power supply at a certain output power point. With the development and innovation of power electronics technology, switching power supply technology is constantly innovating, and this cost reversal point is increasingly moving to the low output power end, which provides a wide development space for switching power supply. The high frequency of switching power supply is the direction of its development.