The role of high-frequency transformers in switching power supplies
Switching transformer with its high conversion efficiency, small size, light weight and work in a wider range of voltages and many other advantages, in the mobile phone charger, battery car charger and a variety of household appliances will be used in the switching power supply, then in the switching power supply we will always see that there is a high-frequency transformer, today we will talk about this high-frequency transformer to talk about its role in the switching power supply.
Switching power supply principle of operation
We know that the switching power supply has a self-excited switching power supply and his excitation switching power supply two categories, and now we have his excitation switching power supply as an example to illustrate its working process, so that we can further illustrate the role of high-frequency transformer in the switching power supply. In his excitation switching power supply by an independent oscillator to generate control pulse signal to control the switching tube on and off, when the switching tube V is in the switching state, then in the high-frequency transformer on the primary winding will have an electric potential, so that it will be induced to the secondary winding, the secondary winding to do the electric potential through the VD2 diode on the electrolytic capacitors to be charged, the electrolytic capacitors play a filtering function, so that It will wait for a stable DC voltage on the load RL.
Switching power supply used in the role of high-frequency transformers
I think in the high-frequency transformer in the switching power supply has the following two main roles, the following we say respectively. The first point is that the use of high-frequency transformers in switching power supplies is to improve the conversion efficiency of the power supply. As the high-frequency transformer iron core is used in the silicon steel sheet core, this silicon steel sheet conductivity is very good, can greatly improve the resistivity and permeability, thus improving the conversion efficiency of the switching power supply, increase its output power.
The second point is to protect the back of the load and personal safety, played a role in safety isolation, but also purify the high-voltage power supply to prevent interference. We assume that the switching power supply in the work due to some reason caused by the output voltage is too high, so that the high voltage will be sent to the protection circuit, then the switching power supply in the protection circuit is opened to protect the mode, it will "order" the switching tube to stop working, but the switching tube stops working, the high-frequency transformer windings at the end of the first time no way! Generate electric potential, so that the secondary winding of the high-frequency transformer can not get the induction of electric potential, the output side of the voltage output, thus protecting the load from high-voltage damage. If you do not use high-frequency transformer once this phenomenon will be very dangerous, if the switching tube is punctured, high voltage output directly on the electrical appliances, directly burned electrical appliances, and even endanger the safety of human life.
