With the development of power connector filtering technology, the filtering technology is highly effective in suppressing electromagnetic interference, especially for EMI signal of switching power supply, which can play a good role in interference conduction and interference radiation. Differential mode interference signals and common mode interference signals can represent all the conduction interference signals on the power supply.
The former mainly refers to the interference signal transmitted between two wires, which belongs to symmetry interference and is characterized by low frequency, small interference amplitude and small generated electromagnetic interference. The latter mainly refers to the transmission of interference signals between the wire and the enclosure (land), which belongs to asymmetric interference, and is characterized by high frequency, large interference amplitude and large generated electromagnetic interference.
Based on the above analysis, EMI signal can be controlled below the limit level specified by EMI standards to achieve the purpose of reducing conduction interference. In addition to effective suppression of interference sources, EMI filters installed in the input and output circuits of the switching power supply are also an important way to suppress electromagnetic interference. The common operating frequency of electronic devices is usually between 10MHz and 50MHz. Many of EMC standard of the lowest conduction interference level limit of 10 MHZ, for high frequency switch power supply EMI signal, as long as the choice of network structure is relatively simple EMI filter or decoupling EMI filter circuit is relatively simple, not only can achieve the purpose of reduce the intensity of high-frequency common-mode current, also can satisfy the filtering effect of EMC regulations.
The design principle of filter electrical connector is based on the above principle. There exists the problem of mutual interference between electrical equipment and power supply and between various electrical equipment, and the filter electrical connector is an ideal choice to reduce the interference. Since each pin of the filter connector has a low-pass filter, each pin can effectively filter the common mode current. In addition, the filter electrical connector also has good compatibility, its interface size and shape size and ordinary electrical connector the same, so, they can be directly replaced.
In addition, the use of filter power connector also has a good economy, which is mainly because the filter power connector only needs to be installed in the port of the shielded case. After it eliminates the interference current in the cable, the conductor will no longer feel the interference signal, so it has a more stable performance than the shielded cable. The filter electrical connector does not have high requirements for the end connection of the cable, so it does not need to use high-quality shielded cable at all, which further reflects its better economy.
Post time: Oct-19-2019