Ireland the switching frequency of the AC-DC switching power supply module?(4)

When testing electronic and electrical equipment, the electronic and electrical equipment shall be tested for conducted interference voltage emission at its 48V input power supply terminal. Although the test frequency bands of different standards are different, the test frequency bands of most products are 150K~30M. It can be seen from the lower limit of the test frequency that the operating frequency of the switching 48V input power supply is close to 150K, and the more difficult it is to deal with the conducted disturbance.

3. What special applications are required for the power switching frequency?

In some special cases, the circuit operation is more sensitive to the switching noise of the 48V input power supply. Such as power carrier, wireless communication, wireless identification, etc. The 48V input power supply requirements for power carrier applications are as follows.

At the same time, the design of the high-frequency switching transformer winding in the module switching power supply is also very important. The winding of the high-frequency switching transformer not only affects the copper loss, but also relates to the coupling between the high-frequency switching transformer windings, and also affects the iron loss of the high-frequency switching transformer. Influence, the design and manufacture of high-frequency switching transformers have a great impact on the performance of the module switching power supply

At present, the power carrier is mainly used for intelligent carrier in the home, remote meter reading system, and remote street lamp control system. The use range of the carrier frequency of power lines in my country is 9KHz ~ 500KHz, and the carrier bandwidth is 4KHz. The development of power carrier is very limited due to the change of power line impedance and the interference of power line noise. In order to increase the communication distance of the power carrier, we must move away from the power switching frequency of the circuit carrier unit. The carrier frequencies currently used in China are 115KHz and 132KHz. In this case, the switching frequency is around 60KHz for the 48V input power supply.