The main working principle of switching power supply
The main working principle of a switching power supply is that the MOS tubes of the upper and lower bridges are alternately connected. Firstly, current flows into the MOS tube of the upper bridge, and the storage function of the coil is used to gather electrical energy in the coil. Finally, the MOS tube of the upper bridge is turned off, and the MOS tube of the lower bridge is turned on. The coil and capacitor continue to supply external power. Then turn off the lower bridge MOS transistor, and then turn on the upper bridge to allow current to enter. This is repeated because the MOS transistor needs to be turned on and off in turn, so it is called a switching power supply.
However, linear power sources are different. Without the intervention of a switch, the water supply pipe is constantly discharging water, and if there is too much, it will leak out. This is what we often see in some linear power sources, where the Mos pipe generates a lot of heat, and all the unused electricity is converted into thermal energy. From this perspective, the conversion efficiency of linear power sources is very low, and when the heat is high, the lifespan of the components is bound to decrease, affecting the final use effect.
The main difference between switching power supplies and linear power supplies is their working mode.
The linear power supply power device works in a linear state, which means that it always works when used, resulting in low work efficiency, usually between 50 [%] and 60 [%]. It can also be said that it is a good linear power supply. The working mode of a linear power supply requires a voltage converter to convert it from high voltage to low voltage. Generally, it is a transformer, but there are also other types of KX power supplies that output DC voltage through rectification. In this way, his volume becomes large, bulky, inefficient, and generates a lot of heat. He also has his advantages: small ripple, good adjustment rate, and low external interference. Suitable for use in analog circuits, various amplifiers, etc.
Switching power supply. His power device works in a switching state (one on and one off, one on and one off, with a very fast frequency. Generally, the frequency of a flat panel switch power supply is between 100-200KHz, and that of a module power supply is between 300-500KHz). In this way, the loss is small, the efficiency is high, and there is also a requirement for the transformer to use materials with high magnetic permeability. There's a bit of ink on it. His transformer is just a word small, with an efficiency of 80% to 90%. It's said that the best VICOR module in the United States is as high as 99%. Switching power supplies have high efficiency and small size, but compared to linear power supplies, their ripple and voltage and current adjustment rate are discounted.
