Solving The Electromagnetic Compatibility Of The Power Adapter

The interference of the power adapter is a common problem, we can solve it from the electromagnetic compatibility of the power adapter. The solution is mainly divided into three aspects: reducing the interference signal generated by the interference source, cutting off the propagation path of the interference signal, and enhancing the anti-interference ability of the interfered body.

For the external interference to the power adapter, such as the harmonic current of power supply cable, the conduction interference of power supply cable, the radiation interference of electromagnetic field, etc., only can be solved by reducing interference. On the one hand, it can enhance the design of the input/output filter circuit, improve the performance of the active power factor compensation (APFC) circuit, reduce the voltage and current rate of change of the switch tube, rectifier, and freewheeling diode, and adopt various soft switch circuit topology and control methods., etc.; on the other hand, strengthen the shielding effect of the case, improve the leakage of the gap of the case, and have a good grounding treatment.

In terms of the transmission path, it can appropriately increase TUS with high anti-interference ability, high-frequency capacitors, ferrite beads and other components to improve the anti-interference ability of small-signal circuits, add appropriate insulation and withstand voltage treatment to the small-signal circuits closed to the case, etc.,. The radiator of the power device and the electromagnetic shielding layer of the main transformer should be properly grounded; the large-area grounding between the control units should be shielded with a grounding plate; on the rack of the rectifier, The electromagnetic coupling and the layout of the ground wire of the whole machine should be considered between the rectifiers to improve the stability of the internal work of the power adapter.