Switching power supply output voltage has three ways of working: direct output voltage way, average output voltage way, and amplitude output voltage way. The first one is mostly used in DC/AC inverter power supply, or DC/DC voltage conversion; the last two are mostly used in switching voltage regulator power supply. Next will introduce two kinds of switching power supply output voltage transformation.
Here is the content:
DC/DC conversion
AC/DC conversion
DC/DC conversion
The DC/DC conversion in switching power supply is to transform the fixed DC voltage into a variable DC voltage, also known as DC chopper. There are two working modes of chopper, one is the pulse width modulation mode Ts unchanged, change TON (general), the other is the frequency modulation mode, ton unchanged, change Ts (easy to produce interference). Its circuits can be divided into the following categories:
Buck circuit - buck chopper, its output average voltage U0 is less than the input voltage Ui, the polarity is the same.
Boost circuit - boost chopper, the output average voltage U0 is greater than the input voltage Ui, the polarity is the same.
Cuk circuit - buck or boost chopper, whose output average voltage U0 is greater or less than the input voltage Ui, with opposite polarity and capacitive transmission.
AC/DC Conversion
The AC/DC conversion in the switching power supply can transform AC into DC, and the power flow can be bidirectional. The power flow from the source to the load is called "rectification", and the power flow from the load back to the source is called "active inverter". The input AC of AC/DC converter is 50/60Hz, and because it must be rectified and filtered, a relatively large filter capacitor is necessary. At the same time, due to the limitations of safety standards and EMC instructions, THE AC input side must add EMC filtering and use components that meet safety standards, thus limiting the miniaturization of AC/DC power supply volume. In addition, because of the internal high frequency, high voltage, high current switch action, it makes it more difficult to solve EMC problems. This also put forward a high requirement for the internal high-density installation circuit design. For the same reason, the high voltage and high current switch increase the working loss of power supply and limit the process of AC/DC converter modularization. Therefore, the power supply system optimization design method must be adopted to make its working efficiency reach a certain degree of satisfaction.
AC/DC converters can be classified according to the wiring of the circuit, half-wave circuit, full-wave circuit. The number of phases of the power supply can be divided into, single-phase, three-phase, multi-phase. According to the circuit, the working quadrant can be divided into one quadrant, two-quadrant, three quadrants, four-quadrant.
DC/DC conversion and AC/DC conversion is an essential tool in switching power supply. And it is the responsibility of every manufacturer to produce switching power supplies that meet the standards to ensure the safety of electricity and the healthy development of the market. Zhejiang Ximeng Electronic Technology Co., Ltd. has conducted several tests on the soft wires for connection before leaving the factory, and the quality pass rate is guaranteed. If you are in the switching power supply business, you can consider our cost-effective products.
