Shenzhen core wholesale

    Magnetic core: apply glue to the middle part of the shaft core-magnetic block and shaft core are placed into the mold and compacted-put into the mold and magnetized-magnetic force detection (completed to be assembled)

    Magnetic core, also known as magnetic ring, refers to a sintered magnetic metal oxide composed of various iron oxide mixtures, and voice coils, basins, etc. are important parts of the speaker, which are widely used In the coils and transformers of various electronic equipment

    As the name implies, the magnetic core is of course used to conduct magnetism, such as low-frequency transformers/inductance cores in general power supplies, switches High-frequency magnetic cores in transformers/inductors in power supplies and high-frequency applications.

    His main role is in two aspects.

   ;  The use of magnetic cores can effectively shield EMI interference, isolate or filter out the high-frequency noise pulse interference of the power supply connection wire entering the equipment circuit, and it plays a pivotal role in dealing with harmonic interference.

     The use of magnetic cores

    The magnetic ring that we usually see at one or both ends of the power line or signal line of electronic equipment is a common mode choke. The common mode choke can form a large impedance to the common mode interference current, but has no effect on the differential mode signal (the working signal is a differential mode signal), so it is simple to use without considering the signal distortion. And the common mode choke does not need to be grounded and can be directly added to the cable. The number of turns of the magnetic ring will be the whole bundle

    magnetic core

    the cable is formed by passing through a ferrite magnetic ring A common mode choke coil is installed, and the cable can also be wound several turns on the magnetic ring as required. The more the number of turns, the better the suppression effect on lower frequency interference, and the weaker the suppression effect on higher frequency noise. In actual engineering, the number of turns of the magnetic ring should be adjusted according to the frequency characteristics of the interference current. Usually when the frequency band of the interference signal is wide, two magnetic rings can be put on the cable, each of which surrounds a different number of turns, so that both high-frequency interference and low-frequency interference can be suppressed at the same time. From the point of view of the mechanism of the common mode choke coil, the larger the impedance, the more obvious the interference suppression effect. The impedance of the common mode choke coil comes from the common mode inductance Lcm=jwLcm. It is not difficult to see from the formula that for a certain frequency of noise, the larger the inductance of the magnetic ring, the better. But the actual situation is not the case, because there are parasitic capacitances on the actual magnetic ring, which exists in parallel with the inductance. When encountering high-frequency interference signals, the capacitive reactance of the capacitor is small, which short-circuits the inductance of the magnetic ring, thereby making the common mode choke ineffective. According to the frequency characteristics of the interference signal, nickel-zinc ferrite or manganese-zinc ferrite can be selected. The high frequency characteristics of the former are better than the latter. The permeability of manganese-zinc ferrite is in the thousands to tens of thousands, while the magnetic permeability of nickel-zinc ferrite is in the hundreds to thousands. The higher the permeability of ferrite, the greater the impedance at low frequencies and the smaller the impedance at high frequencies. Therefore, when suppressing high-frequency interference, nickel-zinc ferrite should be used; otherwise, manganese-zinc ferrite should be used. Or put manganese-zinc and nickel-zinc ferrite on the same cable at the same time, so that the interference frequency band that can be suppressed is wider. The greater the difference between the inner and outer diameters of the magnetic ring and the greater the longitudinal height, the greater the impedance. However, the inner diameter of the magnetic ring must be tightly wrapped around the cable to avoid magnetic leakage. The installation position of the magnetic ring should be as close to the interference source as possible, that is, it should be close to the inlet and outlet of the cable.