EN
With the continuous progress of science and technology, electronic products have been brought forth, thus promoting the widespread use of electronic weighing scales. In terms of quality issues, the abnormalities of electronic weighing scales caused by interference and grounding cannot be ignored, as these abnormalities lead to damage to electronic components due to lightning strikes, drift in display readings due to poor grounding, and even equipment damage. In order to thoroughly solve the above problems, it is necessary to conduct research and analysis on interference factors.
In the case of power supply interference, surges typically occur, such as induction charges on the power line caused by lightning, leading to blown fuses, damaged printed circuit boards, and damaged bridge rectifiers. A complete grounding system can protect against the interference of the power supply. If the grounding system is normal, the losses caused by grounding faults will be greatly reduced, as these faults are suppressed and eliminated by the grounding system.
Under the interference of AC power, components and microprocessors can be damaged. Generally, for AC power supply, the voltage is often less than 0.2V, while being connected to the ground wire at the ground stake. The best way to solve AC power interference is to ground treatment or use a voltage source with filtering function.
The reason for induction interference is that the inductor disrupts the magnetic field. This interference typically appears in the form of sharp high voltages, which are much higher than the original voltage and can cause various faults and permanent damage to the equipment. In general, this voltage mainly manifests as capacitive coupling, inductive coupling, and electromagnetic field radiation. The form of interference circuit is mainly common mode. The main measure to solve electric field coupling interference is shielding. During the shielding process of electric field coupling interference, the shielding layer of the wire should not be used as a ground wire. This is because the magnetic field will be formed in the shielding layer under the influence of ground loop current, causing interference to the shielded wire. A commonly used treatment method is to single-point ground the shielding layer, and ground at any one end. By using shielding to suppress the interference of the magnetic field, they have been shielded with magnetic materials due to production process constraints.
Under the influence of radio frequency, the display of the electronic weight may show inaccurate readings. In this case, it is necessary to check the grounding equipment, inspect the length of the grounding wire, verify the shieldness of the grounding wire, and check if the filter is working properly.
Interference caused by static electricity is more destructive compared to interference caused by radio frequency. When the electronic weight equipment is moistened, static interference is more common. Sensors and sensitive components are usually affected by static interference, leading to damage, equipment shutdown, and chaotic display. Common methods to overcome this interference include equipment grounding, signal line shielding, and other measures.
Increase the distance between grounding devices. If the DC ground and lightning protection ground do not share the grounding body, the distance between them should be more than 5 meters.
In order to reduce mutual interference, increase the difference in burial depth of grounding bodies. Increasing the burial depth to reduce grounding resistance is too costly. In general, increasing the length of the grounding body appropriately also yields ideal results.
The higher the electrical conductivity of the shielding material, the more the interference from the other side can be greatly reduced. Additionally, the thicker the shielding object, the better the shielding effect it achieves.
To reduce interference, the grounding wire should be kept away from the neutral point grounding wire system of lightning protection or power grid. If the grounding wire is long, it should not be parallel to high-power power lines, nor closely adhered to them.
