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

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 24V input power supply equipment will be reduced to the maximum, which is not conducive to miniaturization. When the switching 24V 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.

Power active filter is a new type of power electronic device that can dynamically suppress harmonics. It can overcome the shortcomings of traditional LC filters and is a promising harmonic suppression method. The filter consists of a bridge switching power converter and a specific control circuit. The difference from the traditional switching power supply is: (1) not only feedback the output voltage, but also feedback the average input current; (2) the current loop reference signal is the product of the voltage loop error signal and the full-wave rectified voltage sampling signal.

2. Turkmenistan 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 24V 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 24V input power supply is close to 150K, and the more difficult it is to deal with the conducted disturbance.