Anti-interference circular and introduce principle of | | | action set _ ndfeb strong magnet manufacturers
Electromagnetic compatibility (anti-interference circular definition
For EMC, is refers to an electronic equipment is neither interfere with other equipment, at the same time, it is not affected by other equipment.
Electromagnetic compatibility and the security of the familiar, is one of the most important indicators of product quality.
Involve the personal and property safety and electromagnetic compatibility is related to personal and environmental protection.
Anti-interference principle and function of circular and digital devices with a cylindrical transmission lines.
Magnetic ring is circular, anti-interference, or absorb copper, ferrite beads.
Why to set up the anti-interference magnetic ring?
Computer case motherboard, CPU, power supply, and within the IDE cable are working in the high frequency condition, in case there is a lot of space due to stray electromagnetic interference signal, and the intensity of the signal is outside the case several times to dozens times!
No circular and USB cable in this space without shielding measures, the USB cable will become very good antenna, receiving all kinds of clutter in the surrounding environment of high frequency signals, and the signal superimposed on the original transmission signal, even change the original transmission of useful signal, it's easy to have a problem.
In order to improve the transmission rate and stability, and to reduce the transmission lines when transmitting data to other devices, such as the interference of sound card, electrostatic shielding layer is designed.
The shielding layer is made up of a thin metal foil or more strands of fine woven wire mesh, application of the surface of the electrostatic field effect.
Is the data transmission line on the appearance of bread a layer of metal film, and the shielding layer and chassis grounding, can well the data line and space interference signal isolation!
Absorption of the circular, also called ferrite beads, when used in the separation of removable magnetic ring, it is commonly used in electronic circuit anti-interference components, have very good inhibitory effect to high frequency noise, the use of ferrite materials (general
Copper under different frequencies have different impedance characteristics, generally in the low frequency impedance is very small, when the signal frequency impedance rise sharply increases the circular performance.
Through the normal useful signal is very good, and can restrain the high frequency interference signal through very good, and low cost.
Ferrite anti-interference anti-jamming core ferrite core characteristics is developed in recent years, the cheap and fine interference suppression devices, its effect is equivalent to a low-pass filter, better solve the power cord, the high frequency interference suppression and connector line problem, and is simple to use, convenient, effective, take up the space is not large, and a series of advantages, to suppress electromagnetic interference with ferrite anti-jamming core (
Is a simple and effective method in the economy, has been widely used in a variety of military or civilian, such as computers, electronic devices.
Ferrite is a kind of using high magnetic conductivity material permeability close one or more other magnesium, zinc, nickel and other metal burn together and become, in 2000 ℃ at low frequencies, the sensibility of ferrite anti-jamming core presents very low impedance value, does not affect the useful signal transmission on the data line or telecom.
At high frequencies, and starting from about 10 MHZ, impedance increases, the inductance component remains very small, the resistive component increases quickly, when there is high frequency energy through the magnetic materials, resistive component would have to convert that energy into heat energy dissipation.
Thus constitutes a low-pass filter, the attenuation of high frequency noise signals have big, but useful for low frequency signal of impedance can be ignored, does not affect the normal work of the circuit.
EMI absorption ring/bead is a kind of made of ferrite components, is a kind of absorption loss type component.
Its features are: absorption of high frequency signal and the absorption of energy is converted into heat dissipation, thus suppressing high frequency interference signals along a wire transfer, the purpose of the equivalent impedance of the resistance component is a function of frequency, changes with frequency.
EMI absorption ring/bead effective frequency band of 2 1000 MHZ, best performance spectrum is 5 200 MHZ, in the spectrum absorption impedance to maintain as a constant.
EMI absorption ring/bead when the choice must pay attention to: through the current size is proportional to the element size, both disorders, easy cause saturation, reduce the device performance, the effective method to avoid saturation is the power of the two wires (
Positive, negative or fire, earth)
At the same time through a circular.
Copper in use is also a good way is to get through the copper wire repeated string a few times, then can be improved through the loop area, increase the equivalent length of absorption, and make full use of the magnetic ring with hysteresis characteristics, improve the low-level features.
Its manufacturing process and mechanical properties are similar to those of ceramics.
Its electromagnetic properties and add in the process of metal composition and sintering time, temperature and gas composition.
Packing type magnetic ring, as far as possible choose smaller inner diameter, length of long circular and, at the same time, the circular must cover the cable tightly, namely the circular diameter is to work closely with the outer diameter of the cable size.