What is switching power supply?

With the development and innovation of power electronics skills, switching power supply skills are also constantly innovating. Nowadays, switching power supply is widely used in almost all electronic equipment with the characteristics of small size, light weight and high power. It is an indispensable power supply method for the rapid development of electronic information industry.

Switching power supply is a power supply that uses modern power electronics skills to control the timing ratio of switch tube registration and shutdown, and maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET.

The switching power supply is relative to the linear power supply. Its input directly rectifies the alternating current into direct current, and then, under the action of the high-frequency vibration circuit, uses the switch tube to control the current on and off, forming a high-frequency pulse current. With the help of inductance (high-frequency transformer), it can output stable low-voltage direct current.

Because the magnetic core size of the transformer is inversely proportional to the square of the switching power supply operating frequency, the higher the frequency, the smaller the iron core. In this way, the transformer can be greatly reduced, and the weight and volume of the power supply can be reduced. And because it directly controls DC, the power of this power supply is much higher than that of linear power supply. This saves power, so it is favored by people. But it also has defects, that is, the circuit is complex, maintenance is difficult, and the pollution to the circuit is serious. The power supply has a large noise and is not suitable for some low-noise circuits.