Detailed working principle of switching power supply
As the name implies, switching power supply is to use electronic switching devices to realize switching on and switching of electronic switching devices through the control circuit to achieve voltage regulation and automatic stabilization. Compared with traditional power supplies, switching power supplies have lower cost and output power Higher, so the switching power supply has a broader market development prospect, and is deeply loved by the majority of friends. How much do you know about the working principle of the switching power supply? Next, I will explain the relevant content of the working principle of the switching power supply in detail.
Analysis of working principle of switching power supply
For those who love power supply physics, in fact, they still have a good understanding of the working principle of switching power supplies. In linear power supplies, power transistors are working, and in linear power supplies, it is PWM switching power supplies that cause closure or disconnection. In the two states of disconnection, plus the voltage of the power transistor is relatively small, a large current will be produced. When the switching power supply is turned off, it is reversed, the voltage is large, and the current will be special. Small, and the controller that controls the working principle of the switching power supply is to better maintain stability and bring safety to people's living environment.
Switching Power Supply Working Conditions
In addition to the working principle of the switching power supply described above, the working principle of the switching power supply also has certain working conditions when it is running. For example, the switch is not in a linear state when it is working, but under the operation of electronic appliances. In addition, when DC and switching power supply are working, they are DC, not AC; the high frequency of the last switching power supply, under the working state of electronic appliances, is high frequency, not close to the low frequency state of work! In the working principle of switching power supply, these working conditions are certain.
Main features of switching power supply
The birth of every product has its own main characteristics, even the switching power supply is the same. So what are the main features of the switching power supply in addition to the above different working principles of the switching power supply? First of all, from the appearance, it is lighter in weight and smaller in size. Because no power frequency transformer is used, the weight and volume of the switching power supply are only It is about 20% to 30% of the linear power supply; in addition, there is another very important feature. From the working principle of the switching power supply, it has high efficiency and low energy consumption. In the closed and disconnected state, the conversion efficiency is very high, generally around 60% to 70%, and under the linear power supply state, it is around 30% to 40%.
In the current market, this kind of high-frequency switching power supply adopting a closed loop system can also be divided into two types according to the structure: the power supply with active PFC design and the power supply with passive PFC design. Because the power supply of active PFC design is more expensive than that of passive PFC design, we can simply think that the power supply of active PFC design is a relatively high-end power supply, while the power supply of passive PFC design is a relatively low-end power supply . Below we will mainly explain the working principle of active PFC switching power supply.
Active PFC switching power supply: Active PFC circuits usually use two power MOSFET switches. These switching tubes are generally placed on the heat sink on the primary side. For ease of understanding, we use letters to mark each MOSFET switch tube: S stands for Source (Source), D stands for Drain (Drain), and G stands for Gate (Gate).
Active PFC switching power supply: PFC diode is a power diode, which usually adopts the packaging technology similar to that of power transistor. . The inductance in the PFC circuit is the largest inductance in the power supply; the filter capacitor on the primary side is the largest electrolytic capacitor in the primary side of the active PFC power supply. Active PFC control circuits are usually based on an IC integrated circuit.
Through Xiaobian's introduction to the working principle of switching power supply, do you have more understanding and understanding of the working principle of switching power supply? Switching power supply is mainly divided into two types: active and passive. The working principle of switching power supply, if we master the working principle of switching power supply, it is very important for the application in our life. The application field of switching power supply in today's electronic information industry is very wide, and the working principle of switching power supply is over. I hope everyone can have more harvest.
