Sri Lanka the switching frequency of the AC-DC switching power supply module?(3)

module combination
(1) Parallel expansion. Connecting the output terminals of the same module in parallel can enhance the output capability, but the output voltage of the parallel modules should be adjusted to be consistent to ensure relative current sharing and avoid unnecessary oscillations. For modules with large current output, the lead resistance can also be carefully designed to achieve the effect of current sharing. The number of modules connected in parallel in this way should not exceed 2. At the same time, if one of the module outputs is faulty, the entire system will not work properly. The parallel expansion connection circuit RL is the load.

We know that the lower the switching frequency, the smaller the switching loss, but on the other hand, with the reduction of the switching frequency, the volume of the 48V input power supply equipment will be reduced to the maximum, which is not conducive to miniaturization. When the switching 48V input power supply is working, due to the switching of the switching device, the magnetic core will vibrate, and the frequency range that the human ear can hear is about 20~20000Hz. In order to avoid audible noise, we usually choose to stay away from the 20 frequency KHz.

2. Sri Lanka Disadvantages of choosing an AC-DC control IC with a switching frequency higher than 135K

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.