1. Material selection is the basis
To achieve electromagnetic compatibility, the selection of materials is crucial. First of all, for the shell material, metal materials with good conductivity, such as aluminum, copper, etc., should be given priority. The metal shell can provide a continuous conductive path and play the role of electromagnetic shielding. For example, the aluminum shell not only has good conductivity, but also is relatively light, which is suitable for most automated machinery and equipment. In some cost-sensitive applications, galvanized steel sheets can also be used to enhance their conductivity through galvanizing. In addition to the metal material itself, attention should also be paid to the surface treatment of the material. For some metals that are easily oxidized, such as steel, proper anti-rust treatment can not only protect the material itself, but also maintain its good conductive properties, ensuring that the electromagnetic shielding effect is not damaged.
2. Structural design is the key
In terms of structural design, the sealing of the shell is a key factor in achieving electromagnetic compatibility. Any gap or hole may become a channel for electromagnetic leakage. Therefore, unnecessary openings should be minimized during design, and special treatment measures should be taken for interfaces and vents that must exist. For example, the ventilation holes can adopt a honeycomb structure, which can effectively prevent the leakage of electromagnetic radiation while ensuring air circulation, because when the size of the honeycomb hole is much smaller than the electromagnetic wavelength, it is like a cutoff waveguide, which plays the role of electromagnetic shielding. For the joints of the equipment, good contact should be ensured, and the gaps can be filled with conductive gaskets or electromagnetic sealants to make the shell form a complete electromagnetic shielding body.
3. The importance of grounding design
Good grounding is an important part of the Automation Machine Equipment Shell to achieve electromagnetic compatibility. Shell grounding can introduce the induced electromagnetic interference signal into the earth, thereby protecting the internal circuit of the equipment from interference. The grounding design must first ensure the low impedance of the grounding path, which can be achieved by using a short and thick grounding wire. When multiple devices are connected, a unified grounding system should be established to avoid electromagnetic interference caused by the grounding potential difference between different devices. In addition, the selection of the grounding connection point is also very important. It should be selected at a location with good conductivity of the shell, and the reliability of the grounding connection should be ensured. Check the grounding connection regularly for looseness or corrosion.
4. Collaborative design with internal circuits
The electromagnetic compatibility design of the Automation Machine Equipment Shell cannot be carried out in isolation, but also needs to be considered in coordination with the internal circuits. There is an electromagnetic coupling relationship between the shell and the internal circuit. Therefore, when designing the shell, it is necessary to have a clear understanding of the layout and wiring of the internal circuit. For example, for high-frequency circuits, they should be arranged as far away from the shell as possible to reduce the impact of electromagnetic radiation on the shell. At the same time, the shielding design of the internal circuit should also be combined with the electromagnetic shielding of the shell, such as using a metal shielding cover around the circuit board and connecting it well with the shell to form a multi-level electromagnetic shielding system, so as to more effectively achieve the electromagnetic compatibility of the equipment.
