Serbia the switching frequency of the AC-DC switching power supply module?(2)

Serbia Choosing the switching frequency of the Marine boost power supply does not mean choosing the switching frequency of the Marine boost power supply with a good switching frequency, but the choice is suitable for your own use. Most of the current market is like this. The frequency of the AC-DC switching Marine boost power supply module is between 50K and 135K, and this frequency range can meet most applications. Let's discuss it. Some of the problems that AC-DC encounters when choosing switching frequency:

(2) Parallel connection of redundant hot backup. Connecting the output terminals of the same module through diodes in parallel can enhance the output capability and improve the reliability of the power supply system. In principle, if it cooperates with the corresponding output alarm circuit, put the module on the busbar that can be removed, so that the faulty module can be replaced in time. There is no limit to the number of modules connected in parallel in this way. D is generally a Schottky diode.
(3) Series expansion. Connecting the output terminals of the same module in series can double the output voltage and increase the power accordingly, and the series output terminals must be connected with diodes for protection.

1. Why generally do not choose a switching frequency lower than 50K

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 Marine boost power supply equipment will be reduced to the maximum, which is not conducive to miniaturization. When the switching Marine boost 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.