Selection of parameters required for safety capacitors in switching power supplies

I believe everyone is very familiar with the safety capacitors in switching power supplies, and safety capacitors are still the guardian god! Why do you say this? Compared with ordinary capacitors, safety capacitors do not cause human injury after failure, and there is a guaranteed capacitor. Therefore, safety capacitors are favored by everyone.

In switching power supplies, safety capacitors are used for common-mode filtering. It is connected between L and ground or N and ground. It filters out common mode signals from L to ground or N to ground. Y capacitors are usually used symmetrically. Bypass; decoupling; filtering; energy storage. According to the operating frequency of the switching power supply, the electromagnetic interference generated by the common mode and differential mode can be suppressed, and the common mode and differential mode suppression inductance parameters can be used to calculate the safety capacitance.

The quality of safety capacitor parameters in switching power supplies is generally as large as possible. If fixed frequency harmonics are removed, f = L / 2π * C can be used for calculation. You can choose the appropriate safety capacitor according to the above. Or go to a regular capacitor manufacturer to provide model selection. If you have technical questions, please contact us, we will try our best to solve it for you.