Umgomo oyisisekelo wokufanisa i-impedance
1. isifunda sokumelana okumsulwa
Ku-physics yesikole samabanga aphansi, ugesi utshele inkinga enjalo: ukumelana kwemishini kagesi engu-R, exhunywe kumandla kagesi ka-E, ukumelana kwangaphakathi kwephakethe lebhethri le-r, ngaphansi kwaziphi izimo amandla okukhipha amandla amakhulu kunawo wonke?Uma ukumelana kwangaphandle kufana nokumelana kwangaphakathi, ukuphuma kwamandla okunikezwa kwamandla kumjikelezo wangaphandle kukhulu kunawo wonke, okuwukulinganisa kwamandla wesekethe okuqinile.Uma esikhundleni sesifunda se-AC, okufanayo kufanele futhi kuhlangabezane nemibandela ye-R = r circuit ukuze ifane.
2. ukusabela kwesifunda
I-Impedance circuit iyinkimbinkimbi kunomjikelezo ohlanzekile wokumelana, ngaphezu kokumelana nesifunda kukhona ama-capacitors nama-inductors.Izingxenye, futhi zisebenza kumasekhethi e-AC anemvamisa ephansi noma enemvamisa ephezulu.Kumasekhethi e-AC, ukumelana, amandla kanye ne-inductance yokuvimbela kwamanje okushintshayo kubizwa ngokuthi i-impedance, eboniswa uhlamvu u-Z. Kulokhu, umphumela ovimbelayo we-capacitance kanye ne-inductance ku-alternating current ubizwa ngokuthi i-capacitive reactance kanye ne-inductive reactance futhi ngokulandelanayo.Inani le-capacitive reactance kanye ne-inductive reactance ihlobene nemvamisa ye-alternating current esetshenziswayo ngaphezu kosayizi we-capacitance kanye ne-inductance ngokwayo.Kuyaphawuleka ukuthi, kumjikelezo wokusabela, inani lokumelana R, ukusabela kwe-inductive kanye ne-capacitive reactance ephindwe kabili akukwazi ukwengezwa nge-arithmetic elula, kodwa indlela evame ukusetshenziswa ye-impedance triangulation ukuze kubalwe.Ngakho-ke, isifunda se-impedance ukuze sifinyelele ukufanisa kunamasekhethi aphikisayo kuphela ukuze abe yinkimbinkimbi kakhulu, ngaphezu kwamasekethe okokufaka nokuphumayo ezidingweni zengxenye yokumelana ayalingana, kodwa futhi kudinga ingxenye yokusabela yobukhulu obulinganayo kanye nesibonakaliso sokuphambene (ukufanisa i-conjugate );noma ingxenye ephikisayo kanye nezingxenye zokusabela ziyalingana (okungabonisi ukufanisa).Lapha kubhekiselwa ku-X yokusabela, okungukuthi, i-XL eguquguqukayo kanye nomehluko we-capacitive reactance XC (kumasekhethi ochungechunge kuphela, uma isekethe ehambisanayo iyinkimbinkimbi kakhulu ukubala).Ukuhlangabezana nezimo ezingenhla kubizwa ngokuthi ukufanisa kwe-impedance, umthwalo ongathola amandla aphezulu.
Isihluthulelo sokufanisa i-impedance yi-impedance ephumayo yesiteji sangaphambili ilingana nokuvinjelwa kokufaka kwesiteji sangemuva.I-impedance yokufaka kanye ne-impedance yokukhipha isetshenziswa kabanzi kumasekethe e-elekthronikhi kuwo wonke amazinga, zonke izinhlobo zamathuluzi okulinganisa nazo zonke izinhlobo zezingxenye ze-elekthronikhi.Ngakho-ke yini i-impedance yokufaka kanye ne-impedance yokuphuma?I-impedance yokufaka i-impedance yesifunda emthonjeni wesignali.Njengoba kuboniswe ku-Figure 3 amplifier, i-impedance yayo yokufaka ukukhipha umthombo wesignali E kanye nokumelana kwangaphakathi r, kusukela ku-AB kuphelela ku-impedance efanayo.Inani layo lingu-Z = UI / I1, okungukuthi, isilinganiso se-voltage yokufaka kanye nokufakwayo kwamanje.Ngomthombo wesignali, i-amplifier iba umthwalo wayo.Ngokwezinombolo, inani elilinganayo lomthwalo we-amplifier inani le-impedance yokufaka.Usayizi we-impedance yokufaka awufani kumasekhethi ahlukene.
Isibonelo, ukuphakama kwe-impedance yokufaka (okubizwa ngokuthi i-voltage sensitivity) ye-voltage block ye-multimeter, i-shunt encane kusekethe ngaphansi kokuhlolwa kanye nephutha lokulinganisa libe lincane.I-impedance yokufaka ephansi yebhulokhi yamanje, i-voltage encane yokuhlukaniswa kwesifunda esingaphansi kokuhlolwa, futhi ngaleyo ndlela iyancipha iphutha lokulinganisa.Kuma-amplifiers amandla, lapho i-impedance yokuphuma komthombo wesignali ilingana ne-impedance yokufaka yesekethe ye-amplifier, kubizwa ngokuthi ukufanisa i-impedance, bese isifunda se-amplifier singathola amandla amakhulu ekuphumeni.I-impedance yokuphumayo ukuvinjelwa kwesekethe ngokumelene nomthwalo.Njengomfanekiso wesi-4, ukunikezwa kwamandla kohlangothi olufakiwe lwesekethe kufushane, uhlangothi olukhiphayo lomthwalo luyasuswa, ukuvinjelwa okulinganayo okuvela ohlangothini oluphumayo lwe-CD kubizwa ngokuthi i-impedance yokuphuma.Uma i-impedance yokulayisha ingalingani nomphumela wokuphumayo, obizwa ngokuthi i-impedance mismatch, umthwalo awukwazi ukuthola umkhawulo wamandla okukhiphayo.Isilinganiso se-voltage ephumayo engu-U2 kanye ne-I2 ephumayo yamanje ibizwa ngokuthi i-impedance yokuphumayo.Usayizi we-impedance wokukhipha uncike kumasekhethi ahlukene anezidingo ezahlukene.
Isibonelo, umthombo we-voltage udinga i-impedance ephansi yokukhipha, kuyilapho umthombo wamanje udinga i-impedance ephezulu yokukhipha.Ngomjikelezo we-amplifier, inani le-impedance yokuphumayo libonisa amandla ayo okuthwala umthwalo.Ngokuvamile, i-impedance encane yokukhipha iphumela kumthamo omkhulu wokuthwala umthwalo.Uma i-impedance yokukhipha ingakwazi ukufaniswa nomthwalo, i-transformer noma isifunda senethiwekhi singangezwa ukuze kuzuzwe umdlalo.Isibonelo, i-amplifier ye-transistor ngokuvamile ixhunywe ku-transistor okukhiphayo phakathi kwe-amplifier nesipika, futhi i-impedance yokuphuma kwe-amplifier ifaniswe ne-impedance eyinhloko ye-transformer, futhi i-impedance yesibili ye-transformer ifaniswe ne-impedance isikhulumi.I-impedance yesibili ye-transformer ifaniswe nokuvinjelwa kwesipikha.I-transformer iguqula isilinganiso se-impedance ngokusebenzisa isilinganiso sokujika sama-windings ayisisekelo kanye nesesibili.Emijikelezweni yangempela ye-elekthronikhi, evame ukuhlangana nomthombo wesignali kanye nesifunda se-amplifier noma isifunda se-amplifier kanye ne-impedance yomthwalo ayilingani nesimo, ngakho-ke ayikwazi ukuxhunywa ngokuqondile.Isixazululo ukwengeza isifunda esifanayo noma inethiwekhi phakathi kwabo.Okokugcina, kufanele kuqashelwe ukuthi ukufaniswa kwe-impedance kusebenza kuphela kumasekhethi kagesi.Ngenxa yokuthi amandla amasiginali adluliswa kumasekhethi e-elekthronikhi abuthakathaka ngokwemvelo, ukufanisa kuyadingeka ukuze kwandiswe amandla okukhiphayo.Kumasekhethi kagesi, ukufanisa ngokuvamile akucatshangelwa, njengoba kungaholela ekuphumeni okukhulu kwamanje kanye nokulimala komshini.
Ukusetshenziswa kwe-Impedans Matching
Kumasiginali avamile wemvamisa ephezulu, njengamasiginali wewashi, amasiginali webhasi, futhi kufika kumakhulu ambalwa amamegabhayithi amasignali e-DDR, njll., i-transceiver inductive yedivayisi evamile kanye ne-capacitive impedance incane ngokuqhathaniswa, ukumelana okuhlobene (okungukuthi, ingxenye yangempela the impedance) okunganakwa, futhi kuleli qophelo, ukufanisa i-impedance kudinga kuphela ukucabangela ingxenye yangempela ye-ingaba.
Emkhakheni wefrikhwensi yomsakazo, amadivaysi amaningi anjengezimpondo, ama-amplifiers, njll., i-impedance yawo yokufaka nokuphumayo ayiyona into yangempela (ayikona ukumelana okumsulwa), futhi ingxenye yayo ecatshangelwayo (i-capacitive noma inductive) inkulu kangangokuthi ayikwazi ukushaywa indiva. , khona-ke kufanele sisebenzise indlela yokufanisa i-conjugate.
Isikhathi sokuthumela: Aug-17-2023