With the rapid development of power electronic technology and switching industry, the relationship between power electronic equipment and people's work and life has become increasingly close, and electronic equipment is inseparable from reliable power supply. In the 1980s, computer power supply fully realized switching power supply, taking the lead in After completing the replacement of computer power supply, switching power supply entered various electronic and electrical equipment fields in the 1990s. Program-controlled switches, communications, electronic testing equipment power supplies, control equipment power supplies, etc. have been widely used switching power supplies, which has promoted switching power supply technology. of rapid development. 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 composed of pulse width modulation (PWM) control ICs and MOSFETs. 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. At a certain output power point, the cost of linear power supply is higher than that of switching power supply, and this cost reversal point. With the development and innovation of power electronic 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 its development direction. High frequency makes switching power supply miniaturized, and makes switching power supply enter a wider range of applications, especially in the field of high-tech, which promotes the miniaturization and lightness of high-tech products. change. In addition, the development and application of switching power supply are of great significance in saving energy, saving resources and protecting the environment.