The feedback coil is used to sample the voltage, thus controlling the pulse width and stabilizing the output voltage.
Switching power supply, also known as switching power supply and switching converter, is a high-frequency electric energy conversion device. Switching power supply is a kind of power supply which uses modern power electronics technology to control the time ratio of switching tube on and off and maintain stable output voltage. Switching power supply generally consists of pulse width modulation (PWM) control IC and MOSFET. Compared with linear power supply, the cost of switching power supply and linear power supply increases with the increase of output power, but the growth rate is different. At a certain output power point, the cost of linear power supply is higher than that of switching power supply, which is called cost inversion point. With the development and innovation of power electronics technology, switching power supply technology is also constantly innovating. Switching power supply is widely used in almost all electronic equipment because of its small size, light weight and high efficiency, and it is an indispensable power supply mode for the rapid development of electronic information industry today.