Analysis of acdc power supply module and dcdc power supply module

acdc power moduleCompared with the dcdc power supply module, the larger power is generally the switching power supply mode, so the general input even reading is a wider power supply range, and the size of the transformer will be smaller and the efficiency will be higher.

ACDC conversion is to convert AC to DC, and its power flow can be bidirectional. The power flow is from the power source, and the load is called "rectification". The power returned from the load to the power source is called "active inverter". The AC/DC converter input is 50/60Hz alternating current, because it must be rectified and filtered, so a relatively large filter capacitor is indispensable. At the same time, due to safety standards (such as UI, CCE, etc.) and EMC directives Restrictions (such as IEC, FCC, CSA), the AC input side must add EMC rate wave power and use components that meet safety standards, which limits the miniaturization of the AC/DC power supply. In addition, due to the internal high-frequency, high-voltage, and high-current switching actions, it is more difficult to solve the EMC problem, which also puts forward high requirements for the design of internal high-density mounting circuits. For the same reason, high-voltage, high-current switching increases the loss of a lot of power supplies, limiting high requirements. For the same reason, high-voltage, high-current switching increases the operating loss of many power supplies, which limits the process of modularization of AC/DC converters. Therefore, power system optimization methods must be adopted to achieve a certain degree of satisfaction with the efficiency of the power supply system.

The dcdc transformation is to transform a fixed direct current voltage into a variable direct current voltage, also known as a direct current transient wave. There are two working modes of the temporary wave device, one is the pulse width modulation mode Ts unchanged, changing ton (general); the other is the frequency modulation mode, ton unchanged. Changing Ts (prone to interference), the specific circuits are as follows:

(1) BUCK circuit is a step-down temporary wave device, the average output voltage Vo is less than the input voltage Vt, the polarity is the same.

(2) BUCK circuit is a voltage temporary wave device, its output average voltage v0 is greater than or less than the input voltage, the polarity is the same.

(3) BUCK circuit a voltage or boost temporary wave device, the average output voltage Vo is greater than or less than the input voltage v0, the polarity is opposite, inductive transmission.

(4) BUCK circuit is a step-down or step-up transformer, the average output voltage v0 of which is greater than or less than the input voltage U, the polarity is reversed, and the capacitor transfers.