Switching power supply leakage current standard

The leakage current standard of switching power supply requires a withstand voltage tester. The leakage current value measured by the withstand voltage tester minus the current value of the switching power supply's capacitance to ground is the leakage current of the switching power supply. Or disconnect the switching power supply to the ground capacitance, the leakage current value measured by the withstand voltage tester is the leakage current value that needs to be measured.

What is leakage current

In household appliances, leakage current refers to the safe current between the electrical part of operation and the insulated metal. The leakage current of electrical appliances used for 220V AC is 0.75MA. Very tiny. Connect one end of the AC Haoan meter to the power supply. After removing the ground wire, connect the other end of the AC Haoan meter to the metal room.

What to do if the switching power supply leakage

What to do with the leakage of the switching power supply? The primary high voltage of the switching power supply is isolated by a high-frequency transformer, and theoretically there is no leakage at the output. However, the metal shell of the high-frequency switch is easy to induce voltage, which gives people the feeling of leakage. Generally eliminated by grounding. How to deal with the leakage of the switching power supply? There are individual prevention and control switching power supplies on the market. The high-voltage part of the first-time process is poor. Some solder joints are isolated from the metal shell by insulating paper, which is very dangerous. (AC220V becomes DC300V through low-frequency rectifier bridge and capacitor filtering, and then through high-frequency switch tube and high-frequency isolation transformer to generate alternating current. The secondary end of the high-frequency isolation transformer induces alternating low voltage, which becomes low-voltage direct current through high-frequency rectification and filtering. )

What to do if the switching power supply leaks, it is best to ground the shell. Or on occasions where the requirements are not high, remove the capacitor connected to the housing, and the capacitor connected to the high-voltage part and the low-voltage part.