Hauv cov khoom siv Ethernet, thaum PHY nti txuas nrog RJ45, network transformer feem ntau yog ntxiv.Qee lub network transformer center kais grounding.Qee qhov txuas nrog cov khoom siv hluav taws xob, thiab cov nqi hluav taws xob tuaj yeem sib txawv, 3.3V, 2.5V, 1.8V.Yuav ua li cas txuas lub transformer intermediate kais (PHY kawg)?
A. Vim li cas qee cov kais dej nruab nrab txuas nrog lub hwj chim?Qee qhov grounding?
Qhov no feem ntau yog txiav txim los ntawm UTP tus tsav tsheb hom phy nti.Hom kev tsav tsheb tau muab faib ua kev tsav hluav taws xob thiab kev tsav tsheb tam sim no.Thaum tsav tsheb los ntawm qhov hluav taws xob, nws txuas nrog lub zog hluav taws xob;thaum tsav tsheb los ntawm tam sim no, nws txuas nrog capacitor rau hauv av.Yog li ntawd, txoj kev sib txuas ntawm qhov chaw kais yog ze ze rau UTP chaw nres nkoj tsav tsheb hom phy nti, nrog rau cov ntaub ntawv thiab cov qauv siv ntawm lub nti.
Nco tseg: yog tias qhov nruab nrab kais txuas txuas tsis raug, qhov chaw nres nkoj network yuav tsis ruaj khov heev lossis txawm tias thaiv.
B. Vim li cas qhov sib txawv voltages txuas nrog lub hwj chim mov?
Qhov no kuj tau txiav txim los ntawm UTP chaw nres nkoj theem teev nyob rau hauv PHY nti cov ntaub ntawv siv.Cov theem yuav tsum tau txuas mus rau qhov sib thooj voltage, uas yog, yog tias nws yog 1.8V, rub mus txog 1.8V, yog tias nws yog 3.3V, rub mus txog 3.3V.
Center tap effect:
1. Los ntawm kev muab ib qho qis impedance rov qab txoj kev ntawm hom suab nrov ntawm cov kab sib txawv, cov hom hom tam sim no thiab hom hom voltage ntawm lub cable raug txo;
2. Muab DC bias voltage lossis lub zog hluav taws xob rau qee qhov transceivers.
Kev sib xyaw ua ke RJ45 hom kev tiv thaiv tuaj yeem ua tau zoo dua, thiab kev cuam tshuam ntawm cov kab mob parasitic yog me me;Yog li ntawd, txawm hais tias tus nqi kuj yog qhov siab heev, nws kuj tseem nrov nrog cov engineers vim nws qhov kev sib koom ua ke siab, kev ua haujlwm me me, kev siv hom kev sib tsoo, cov kab mob parasitic thiab lwm yam zoo.
3. Lub luag haujlwm ntawm lub network transformer yog dab tsi?Peb tsis tuaj yeem nqa nws?
Raws li txoj cai, nws tuaj yeem txuas ncaj qha rau RJ45 yam tsis muaj lub network transformer, thiab nws tuaj yeem ua haujlwm ib txwm.Txawm li cas los xij, qhov kev ncua deb yuav raug txwv, thiab thaum txuas nrog rau qib sib txawv network interface, nws kuj yuav muaj kev cuam tshuam.Thiab sab nraud cuam tshuam rau lub nti kuj loj heev.Thaum txuas nrog lub network transformer, nws yog tsuas yog siv rau cov teeb liab theem coupling.1, Txhim kho lub teeb liab, kom qhov sib kis tau ntev dua;thib ob, ua kom cov nti kawg thiab kev sib cais sab nraud, txhim khu kev tiv thaiv kev cuam tshuam, thiab ua kom cov nti tiv thaiv (xws li xob laim);thib peb, thaum txuas nrog ntau theem (xws li qee qhov PHY nti yog 2.5V, qee qhov PHY nti yog 3.3V) ntawm qhov chaw nres nkoj network, yuav tsis cuam tshuam rau ib leeg cov khoom siv.
Feem ntau hais lus, network transformer muaj cov haujlwm ntawm cov teeb liab kis tau tus mob, impedance txuam, waveform kho, teeb liab clutter suppression thiab high voltage rho tawm.
Post lub sij hawm: Jan-12-2021