Lub shielded thaiv system yog los ntawm cov teb chaws Europe. Nws yog cov hlau thaiv txheej ntxiv rau sab nraud ntawm cov kab hluav taws xob zoo tib yam uas tsis muaj kev tiv thaiv. Kev xav, nqus thiab cov nyhuv ntawm daim tawv nqaij ntawm cov hlau thaiv txheej yog siv los tiv thaiv electromagnetic cuam tshuam thiab hluav taws xob hluav taws xob. Lub shielding system tau siv dav siv txoj hauv kev sib npaug ntawm cov khub twisted thiab cov nyhuv thaiv ntawm cov txheej thaiv, yog li nws muaj cov yam ntxwv zoo electromagnetic compatibility (EMC).
Electromagnetic compatibility (EMC) txhais tau hais tias cov khoom siv hluav taws xob lossis cov tshuab hauv network muaj qee lub peev xwm los tiv thaiv electromagnetic cuam tshuam, thiab tib lub sijhawm tsis tuaj yeem tsim hluav taws xob ntau dhau. Hais tias yog, nws yuav tsum tau hais tias lub cuab yeej los yog network system yuav ua hauj lwm ib txwm nyob rau hauv ib tug kuj hnyav electromagnetic ib puag ncig, thiab nyob rau tib lub sij hawm tsis tuaj yeem tawg cov hluav taws xob ntau dhau los cuam tshuam nrog kev ua haujlwm ib txwm muaj ntawm lwm cov khoom siv thiab cov tes hauj lwm.
The balanced characteristics of U/UTP (unshielded) cables are not only determined by the quality of the components themselves (eg twisted pairs), but are also affected by the surrounding environment. Because metal around U/UTP (unshielded), hidden "ground", pulling during construction, bending, etc. will destroy its balance characteristics, thereby reducing EMC performance.
Yog li, tsuas muaj ib qho kev daws teeb meem kom tau txais cov yam ntxwv sib npaug: hauv av txhua lub cores nrog ib txheej ntxiv ntawm aluminium ntawv ci. Aluminium ntawv nyiaj ntxiv kev tiv thaiv rau qhov tsis yooj yim twisted -pair cores, thaum tsim ib qho chaw sib npaug rau U/UTP (unshielded) cables. Yog li tsim dab tsi peb tam sim no hu ua lub thaiv kab thaiv.
Lub hauv paus ntsiab lus ntawm shielding cable yog qhov sib txawv ntawm qhov sib npaug ntawm kev tshem tawm txoj cai ntawm tus khub twisted. Lub shielded cable yog ntxiv ib los yog ob txheej ntawm txhuas ntawv ci nyob rau sab nraum ntawm plaub khub ntawm twisted khub, thiab siv cov hlau los xav txog, nqus thiab daim tawv nqaij cov ntsiab lus ntawm electromagnetic vuag (qhov no yog -hu ua qauv) . Cov nyhuv ntawm daim tawv nqaij txhais tau hais tias qhov kev faib tawm ntawm tam sim no hauv tus neeg xyuas pib hla -section feem ntau yuav muab faib rau ntawm tus neeg xyuas pib raws li qhov zaus nce. Electromagnetic cuam tshuam nkag mus rau hauv lub cable, tab sis kuj tiv thaiv cov teeb liab sab hauv los ntawm kev tawg tawm, cuam tshuam nrog kev ua haujlwm ntawm lwm yam khoom siv.
Experiments show that electromagnetic waves with frequencies exceeding 5MHz can only pass through 38μm thick aluminum foil. If the thickness of the shielding layer exceeds 38 μm, the frequency of electromagnetic interference that can enter the cable through the shielding layer is mainly below 5MHz. For low-frequency interference below 5MHz, the balance principle of twisted pair can be applied to effectively cancel.
According to the earliest definition of wiring, it is divided into two types: unshielded cable-UTP and shielded cable-STP. Later, with the development of technology and different craftsmanship, many different types of shielding were derived. F/UTP Foil Screened Cable Single-layer aluminum foil shielding structure 2． Foil and Braid Screened Cable Double-layer shielding structure of aluminum foil and copper braid a) SF/UTP aluminum foil and copper braid wrapped on the outer layer of four pairs of wires at the same time b) S/FTP (PIMF) wire pair single pair of aluminum foil shielding plus The copper braided mesh PIMF =Pair in Metal Foil wrapped on the outer layer of the four pairs of wires.
The shielded cable's resistance to external interference is mainly reflected in: the integrity of signal transmission can be guaranteed by the shielding system. The shielded wiring system can prevent the transmitted data from being affected by external electromagnetic interference and radio frequency interference. Electromagnetic Interference (EMI) is mainly low frequency interference. Motors, fluorescent lamps and power lines are common sources of EMI. Radio frequency interference (RFI) is high frequency interference, mainly radio frequency interference, including radio, television broadcast, radar and other wireless communications.
Rau kev tiv thaiv electromagnetic cuam tshuam, braided shielding yog qhov kev xaiv zoo tshaj plaws, uas yog, hlau mesh shielding, vim nws tsis tshua muaj kev tiv thaiv. Rau kev cuam tshuam hauv xov tooj cua, cov ntawv hlau hlau thaiv yog qhov ua tau zoo tshaj plaws, vim tias qhov sib txawv tsim los ntawm cov hlau mesh shield tso cai rau siab -frequency signals nkag mus thiab tawm dawb. Rau qhov sib xyaw ua haujlwm ntawm qhov siab thiab qis zaus, kev sib xyaw ua ke ntawm cov ntawv ci hlau txheej thiab hlau mesh yuav tsum tau txais, uas yog, ob npaug - txheej shielded cable hauv daim ntawv ntawm S / FTP, uas tuaj yeem ua rau cov hlau mesh shielding haum rau kev cuam tshuam nyob rau hauv qhov tsawg zaus ntau, thiab cov ntawv hlau hlau shielding Haum rau kev cuam tshuam nyob rau hauv ntau zaus.
The single-layer thickness of the aluminum foil shielding layer in the IBM ACS shielded cable reaches 50-62 μm, which has a more complete shielding effect. At the same time, because only a single layer of shielding is used, it will be simpler for construction, easy to install, and not easy to cause artificial damage during the construction process, and the thickness of the aluminum foil can withstand greater destructive force. This can provide users with higher quality transmission performance.
