Lub luag haujlwm ntawm Terminal Desistors hauv kev txawj tes haujlwm
1. Tiv thaiv cov paib kev xav
Lub hauv paus ntsiab lus tseem ceeb: tuaj yeem siv hluav taws xob sib txawv, qhov twg qhov sib txawv ntawm cov tuaj yeem sib txawv ntawm tuaj yeem {}}}}} l sawv cev rau lub teeb liab xeev.
Txhawm rau kom paub meej tias lub teeb liab kev ncaj ncees ntawm lub tsheb npav, ob qho kawg ntawm lub tsheb npav yuav tsum tau nruab lub davhlauinal tsim nyog.
Kev sib raug zoo sib xws: tus yam ntxwv imporistance ntawm lub tsheb npav yog 120 ohms. Yuav kom ua tiav cov neeg yuam kev thiab tiv thaiv lub teeb liab xav, 120- Ohm terminal resectionor yuav tsum txuas nrog txhua qhov kawg ntawm lub tsheb npav.
Nyob rau hauv txoj kev no, tag nrho cov impedance ntawm lub tsheb npav yog khaws cia nyob ib ncig ntawm lub zog ntawm lub teeb liab thiab tiv thaiv lub teeb liab los ntawm kev coj tus nqi tsheb npav lossis kev sib txuas lus tsis raug.
2. Cov teeb liab kev ncaj ncees
Kev nqus cov teeb meem: Lub davhlau ya nyob tiv thaiv tsis tuaj yeem tiv thaiv cov paib kev cuam tshuam tab sis kuj zoo nqus lub teeb liab kom ntseeg tau tias muaj teeb meem uas ruaj ntseg ntawm lub tsheb npav. Thaum tsis muaj kev tiv thaiv lub davhlau ya dav hlau lossis cov teeb tsa lub davhlau ya nyob twg yog qhov tsis zoo, lub teeb liab yuav ua rau lub zog ncau, ua rau lub sijhawm thiab theem distortion ntawm cov ntaub ntawv thav duab.
Lub tsheb muaj peev xwm khiav ruaj khov: Qhov teeb meem teeb tsa kom raug rau cov teeb liab sib txawv uas tuaj yeem kis tau yog kis tau yog, uas yog qhov tseem ceeb rau lub kaw lus ruaj khov.
Kev teeb tsa ntawm terminal resistors
1. Reactor Tus Nqi Xaiv
Tus nqi txheem: Hauv ib txwm muaj network, tus qauv kev xaiv ntawm lub davhlau ya nyob twg yog 120 ohms (± 1% tseeb). Tus nqi no sib haum rau cov xeeb ceem ntawm lub tsheb npav, yog li 120- Oh} Ohm resist yuav tsum txuas nrog txhua qhov kawg ntawm lub tsheb npav.
Cov chaw nyob: cov davhlau ya nyob tiv thaiv kev yuav tsum tau muab tso rau ntawm lub cev thaum lub tsheb npav kom ua tiav cov teeb tsa kev ua kom haum thiab txo qis tsawg. Qhov no yog qhov tshwj xeeb tshaj yog rau cov tsheb npav ntev (ntau tshaj 10 metres) lossis kev sib txuas lus nrawm (xws li 1 Mbps).
2. Txhim Kho Txoj Kev
Ua-nyob rau hauv lub davhlau ya nyob: Qee cov khoom siv tau yog tsim nrog cov chaw tiv thaiv kev tawm tsam, uas yooj yim heev hauv qee cov ntsiab lus network yooj yim. Txawm li cas los xij, nyob rau hauv cov tes hauj lwm nyuaj, nws yuav tsim nyog rau manually los tsim kho sab nraud terminal resistors tiv thaiv kom ntseeg tau tias qhov tseeb txuam ntawm lub npav impedance.
Kev tswj hwm kev teeb tsa: Hauv cov kab ke tsis muaj kev tiv thaiv lub davhlau ya mus ntau feem ntau yuav tsum tau ua haujlwm rau lub cev sib tw ntawm lub cev muaj peev xwm caij npav. Nco ntsoov tias cov tsim tawm tau yooj yim sib txuas thiab raug txuas rau tuaj yeem {{h thiab tuaj yeem {2}} l.
Cov teeb meem thiab kev daws teeb meem
1. Nco los yog ntau lub davhlau nyob tiv taus
Ploj: yog tias lub davhlau ya nyob twg, tag nrho cov impedance ntawm lub tsheb npav yuav muaj ntau dua tus nqi yuav ua rau muaj tus nqi, uas yuav ua rau muaj kev sib txuas lus, tsis muaj kev sib txuas lus, lossis pob ntawv poob.
Ntau dhau: Yog tias lub npav muaj ntau lub davhlau ya nyob twg (piv txwv li cov imporestance cuam tshuam nrog kev ua yuam kev), ua rau cov phiajcim tsis sib haum thiab cuam tshuam rau kev sib txuas lus zoo.
2. Unmatched tsis kam nqi
Ntau dhau kev tiv thaiv: yog tias lub davhlau ya nyob twg tsis kam muaj nqis heev, teeb meem kev ua kom muaj teeb meem yuav ua rau muaj mob hnyav, ua rau muaj kev nce qib ntxiv.
Tsawg dhau qhov tsis kam: yog tias lub davhlau ya nyob twg tsis tshua muaj nuj nqis, lub teeb liab yuav muaj peev xwm ntau dhau lawm, ua rau nws tsis yooj yim sua kom tau txais cov teeb liab kom raug.
3. Cov hau kev daws teeb meem
Kev tshuaj xyuas lub cev: thawj tshawb xyuas seb puas muaj kev tiv thaiv lub davhlau nyob rau ntawm ob qho kawg ntawm lub npav thiab nco ntsoov tus nqi tiv taus yog 120 ohms. Yog hais tias cov deedors yog xoob lossis muaj kev tiv tauj tsis zoo, nws kuj tseem yuav ua rau tsis ua haujlwm.
Ntsuas tag nrho cov impedance: Siv tshuaj multometer pultimeter los yog impedance kws ntsuam xyuas kom ntsuas tag nrho cov impedance tus nqi ntawm ob qho kawg ntawm lub tsheb npav. Nyob rau hauv ib txwm muaj xwm txheej, nws yuav tsum muaj txog 60 ohms (ob 120 ohm resistors hauv parallel).
WaveFormat tsom xam: Siv ib qho oscilloscope los soj ntsuam cov teeb liab waveforms ntawm tuaj yeem {} _ l. Yog tias xav txog lossis cuam tshuam yog pom, nws yuav cuam tshuam nrog kev teeb tsa tsis raug ntawm lub davhlau ya nyob.
Kev Xeem Ntsuas Cov Teeb Meem: Khiav txoj kev ntsuas kev ncaj ncees hauv lub system los ntsuas seb puas muaj kev tiv thaiv kom raug los sis cov pob ntawv poob qis ntawm pob ntawv ntaub ntawv.
Lub ntsiab
Lub luag haujlwm ntawm lub davhlau ya nyob hauv lub nroog tuaj yeem tsis quav ntsej. Nws tsis tsuas yog ua kom muaj kev ncaj ncees ntawm lub teeb liab, tab sis kuj cuam tshuam ncaj qha rau kev ruaj ntseg thiab kev sib txuas lus zoo ntawm lub system.
Kev xaiv kom raug thiab teeb tsa lub davhlau ya dav hlau tiv taus thiab tshem tawm cov ua txhaum ntawm lub chaw tiv thaiv lub chaw tiv thaiv lub chaw ua haujlwm tseem ceeb ntawm lub tsheb hluav taws xob.
