A:Switching power supply is a type of power supply that utilizes modern power electronics technology to control the time ratio of switch on and off, and maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET. Compared to linear power supplies, the cost of both increases with the increase of output power, but their growth rates vary. The cost of a linear power supply is actually higher than that of a switching power supply at a certain output power point, which is called the cost reversal point. With the development and innovation of power electronics technology, switching power supply technology is also constantly innovating, and this cost reversal point is increasingly moving towards the low output power end, providing broad development space for switching power supply.