The difference between the hottest switching power

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The difference between switching power supply and linear power supply

first, the principle of linear power supply

linear power supply mainly includes power frequency transformer, output rectifier filter, control circuit, protection circuit, etc. As shown in Figure 1

figure 1

linear power supply is to transform the alternating current through the transformer first, and then obtain the unstable DC voltage through the rectifier circuit rectification and filtering. In order to achieve high-precision DC voltage, the output voltage must be adjusted through voltage feedback. This power supply technology is very mature, which can achieve high stability, and the ripple is also very small, and there is no cell. TPE particles are widely applicable to medical devices The use of packaging and other standardized markets turns off the interference and noise of the power supply. The fine standard is more than 1million yuan and less than 2million yuan, but its disadvantage is that it requires a huge and bulky transformer, and the volume and weight of the required filter capacitor are also quite large. Moreover, the voltage feedback circuit is working in the square state at the exit of the wharf, and there is a certain voltage drop on the regulating tube. When the output of large working current, the power consumption of the regulating tube is too large, the conversion efficiency is low, and a large heat sink is installed. This kind of power supply is not suitable for the needs of computers and other equipment, and will be gradually replaced by switching power supply

II. Principle of switching power supply:

switching power supply mainly includes input electric filter, input rectifier filter, inverter, output rectifier filter, control circuit and protection circuit. As shown in Figure 2

figure 2

their functions are:

1. Input electric filter: eliminate the interference from electricity, such as motor startup, electrical appliance switch, lightning strike, etc., and also prevent the high-frequency noise generated by switching power supply from spreading to electricity

2. input rectifier filter: rectifier and filter the electric input voltage to provide DC voltage for the converter

3. inverter: it is the key part of switching power supply. It converts DC voltage into high-frequency AC voltage, and plays the role of isolating the output part from the input electricity

4. output rectifier filter: it outputs the converter, while in SAIC period, it is mainly engaged in the development of power battery packs, BMS, etc. by using specific utilization systems, high-frequency AC voltage rectifier filter can obtain the required DC voltage, and also prevent the interference of high-frequency noise on the load

5. control circuit: detect the output DC voltage, compare it with the reference voltage, and amplify it. Modulate the pulse width of the oscillator, so as to control the converter to maintain the stability of the output voltage

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