01 ntawm 03
Kev Tackling Yog Ib Yam Kev Txim Siab Tshaj Plaws hauv Suab Electronics
Thaum kuv tabtom kawm txog kev tsim suab, ib qho ntawm cov ntsiab lus uas nyuaj tshaj plaws rau kuv tau tuav yog qhov tawm impedance. Kev tawm tswv yim impedance Kuv nkag siab instinctively, los ntawm tus piv txwv ntawm tus neeg hais lus . Tom qab tag nrho, tus neeg tsav tsheb hais lus muaj cov kauj hlau, thiab kuv paub tias lub xov tooj ntawm cov xaim hluav taws xob khiav tsis zoo. Tab sis tso tawm impedance? Vim li cas thiaj yuav ib lub zog los yog muaj teeb meem ua ntej tuaj yeem ua tus tso tawm ntawm nws cov zis, kuv xav tsis thoob? Tsis cia nws xav kom xa txhua yam volt thiab amp los xijpeem nws tsav?
Hauv kuv cov chats nrog nyeem thiab cov neeg txhawb siab los ntawm lub xyoo, kuv tuaj los paub kuv tsis yog tib tug uas tsis tau txais tag nrho lub tswv yim ntawm cov zis impedance. Yog li kuv xav tias nws yuav zoo ua tus primer ntawm tus kawm. Nyob rau hauv tsab xov xwm no, kuv yuav txiav txim siab nrog 3 yam sib txawv thiab ntau ntau zaus: preamps, amps thiab lub mloog pob ntseg.
Ua ntej, cia peb rov qab piav txog lub ntsiab lus ntawm impedance . Kev Tiv Thaiv yog cov ntaub ntawv uas muaj ib yam dab tsi txwv qhov khiav ntawm DC hluav taws xob. Impedance yog qhov tib qhov, tab sis nrog AC tsis DC. Feem ntau, lub impedance ntawm ib feem yuav hloov raws li lub zaus ntawm hluav taws xob teeb liab hloov. Piv txwv li, ib lub kauj me me ntawm hlau yuav muaj ze li ntawm xoom impedance ntawm 1 Hz tab sis siab impedance ntawm 100 kHz. Ib tug capacitor yuav muaj ze li ntawm infinite impedance ntawm 1 Hz tab sis yuav luag tsis muaj impedance ntawm 100 kHz.
Kev tawm impedance yog cov impedance ntawm lub preamp lossis amplifier cov khoom siv zis (feem ntau transistors, tiam sis tejzaum nws yog ib lub cav lossis raj) thiab cov zis txuas hluav taws xob ntawm kev tivthaiv. Qhov no muaj xws li sab hauv impedance ntawm tus ntaus nws tus kheej.
Vim Li Cas Koj Puas Xav Tau Kev Tawm Tsam Zog?
Li ntawd, vim li cas thiaj yuav muaj kev tivthaiv muaj kev tawm impedance? Rau feem ntau, nws yog los tiv thaiv nws tawm tsam kev puas tsuaj los ntawm kev kho mob luv luv.
Cov twj tso zis hluav taws xob nyob hauv tus nqi hluav taws xob tam sim no nws thiaj lis tau. Yog hais tias qhov tso tawm ntawm lub cuab yeej ua luv luv, nws tau raug hais kom xa ib qho loj npaum li cas ntawm tam sim no. Piv txwv, ib lub teeb tawm ntawm qhov teeb meem 2.83-volt yuav tsim ib qho tam sim no ntawm 0.35 amps thiab 1 watt ntawm fais fab mus rau ib qho kev hais lus 8-ohm. Tsis muaj teeb meem dab tsi. Tab sis yog ib lub xaim uas muaj 0.01 ohms impedance tau txuas nrog thoob lub zog ntawm cov zis, qhov teeb meem tseem ceeb ntawm 2.83-volt yuav tsim ib qhov tam sim no ntawm 282.7 amps thiab 800 watts ntawm lub hwj chim. Tias 's deb, deb ntau tshaj li cov zis pab tau. Tshwj tsis yog tias lub amp muaj qee yam ntawm kev tiv thaiv Circuit Court los yog ntaus ntawv, ces cov twj tso tawm yuav ua rau nws kub thiab yuav zaum raug kev puas siab puas ntsws. Thiab yog, nws yuav ntes tau hluav taws.
Muaj qee tus nqi ntawm impedance ua rau hauv cov zis, qhov feem ntau obviously muaj ntau dua kev tiv thaiv ntawm luv circuits, vim hais tias cov zis impedance yog ib txwm nyob hauv Circuit Court. Hais tias koj muaj ib lub pob ntseg pob ntseg nrog ib qho zis impedance ntawm 30 ohms, tsav ib nkawm 32-ohm headphones, thiab koj luv lub mloog pob ntseg qaum ntawm nws ua rau nws nrog ib tug txaj txiab. Koj mus ntawm ib qho tag nrho qhov system impedance ntawm 62 ohms mus rau tag nrho impedance ntawm tej zaum 30.01 ohms, uas tsis yog xws li ib tug loj kawg deal. Yeej tsis tshua muaj ntau tshaj li ntawm 8 ohms mus txog 0.01 ohms.
Yuav Tsum Ua Li Cas Tsi Lawm?
Ib txoj cai dav ntawm ntiv tes xoo hauv suab yog tias koj xav kom tso tawm qhov kev tawm dag zog ua kom tsawg kawg yog 10 zaug qis tshaj qhov kev cia siab tawm tias nws yuav pub mis. Li no, qhov kev tawm impedance tsis muaj kev cuam tshuam txog kev ua tau zoo ntawm qhov system. Yog tias qhov zis impedance ntau tshaj li 10 zaug ntawm qhov tawm tsam impedance uas nws yuav pub, koj tuaj yeem tau txais ob peb yam teeb meem.
Nrog rau txhua lub suab ntawm lub tshuab hluav taws xob, ib qho kev tawm ntau tshaj tawm hauv siab tuaj yeem tsim cov teebmeem filtering uas ua rau muaj kev txwv txawv txawv ntawm anomalies, thiab kuj ua rau cov tso zis ntau zog. Yog xav paub ntxiv txog cov phenomena, mus saib kuv cov khoom thib ib thiab zaum thib ob txog seb cov lus hais lus cables puas tuaj yeem ua rau lub suab zoo.
Cov amplifiers, muaj ib qho teeb meem ntxiv. Thaum lub amplifier txav tus hais lus cone rau pem hauv ntej los yog rov qab, tus neeg hais lus qhov rho tawm dej tawm lub khob rov qab mus rau nws qhov chaw ua haujlwm. Qhov kev ua no ua rau muaj qhov voltage uas yog ces muab pov tseg rov qab rau ntawm lub tshuab thev naus laus zis. Yog hais tias tus amplifier cov zis impedance tsis txaus, nws yuav ua kom luv luv tawm ntawd EMF rov qab thiab ua raws li tus nres ntawm lub khob hlias raws li nws springs rov qab. Yog hais tias tus zauv loj ntawm lub zeem muag impedance siab heev, nws yuav tsis muaj peev xwm nres lub khob sab nraud, thiab lub khob ncauj ntxeem yuav rov mus txog txij nkawm mus txog thaum txhuam lawm. Qhov no ua rau cov nyhuv ua suab nrov thiab ua daim ntawv tseem ceeb tom qab lawv tau nres.
Koj tuaj yeem pom qhov no nyob rau hauv kev ntxub dej cawv ntawm cov amplifiers. Qhov zoo tshaj yog txav mus rau qhov nruab nrab ntawm tus qhauj tawm (8 ohms) muab faib los ntawm qhov tso tawm impedance ntawm amp. Qhov ntau dua tus naj npawb, qhov zoo tshaj qhov kev cuam tshuam kev damping.
Amplifier Tso Tawm Zog
Vim peb nyob nraum tham txog amps, peb pib nrog tus qauv no, uas yog muaj nyob hauv daim duab saum toj no. Hais lus impedances feem ntau yog kwv yees li 6 mus rau 10 ohms, tab sis nws yog ib qho rau cov neeg hais lus yuav poob rau 3 ohms impedance ntawm qee zaus, thiab txawm tias 2 ohms hauv qee zaus. Yog hais tias koj khiav ob tus neeg hais lus nyob rau hauv parallel, raws li kev cai txhim kho feem ntau ua thaum tsim lub suab sib txuam nruab , uas txiav lub impedance hauv ib nrab, qab hau ib tug hais lus uas dips rau 2 ohms tom, hais, 100 Hz tam sim no dips rau 1 ohm ntawm qhov zaus thaum nws khub nrog lwm tus neeg hais lus ntawm tib hom. Qhov ntawd yog ib qho ntaub ntawv huab, ntawm chav kawm, tiam sis tus neeg tsim khoom tsim qauv yuav tsum suav cov huab mob loj heev lossis lawv yuav ntsib ib pawg loj ntawm cov amps tuaj kho.
Yog tias peb xam cov lus qhia tsawg kawg nkaus ntawm 1 ohm, uas txhais tau tias amp yuav tsum muaj qhov tso tawm impedance tsis tshaj li ntawm 0.1 ohm. Obviously, yog tsis muaj chav ntxiv txaus tsis kam mus no amp cov zis los muab cov khoom tso zis uas muaj kev tiv thaiv tiag tiag.
Yog li, tus amplifier yuav tsum ntiav ib co kev tiv thaiv Circuit Court. Qhov ntawd yuav yog ib yam uas ua raws nraim cov amp cov zis tawm tam sim no thiab disconnects cov zis yog hais tias qhov kos tam sim no yog siab dhau heev lawm. Los yog nws yuav yooj yim li ib qho hluav taws xob los yog hluav taws xob rau ntawm AC cov kab hluav taws xob los yog cov ntsia hlau ntawm lub hwj chim. Cov disconnect zog lub zog thaum qhov teeb meem tam sim no ntau tshaj qhov teeb meem ntawm amp.
Incidentally, yuav luag txhua lub raj xa hluav taws xob siv cov cav tsim tawm, thiab vim tias cov qhov hluav taws xob tso tawm tsuas yog cov xaim ntawm cov hlau xaim nyob ib ncig ntawm ib txheej hlau, lawv muaj ntau yam pauv ntawm lawv tus kheej, qee zaum ntau npaum li 0.5 ohm lossis ntau tshaj. Nyob hauv qhov tseeb, simulate lub suab ntawm lub raj hauv amp hauv nws cov Sunfire solid-state (transistor) amplifiers, famed designer Bob Carver ntxiv rau ib hom "tam sim no" uas muab tso rau 1-ohm resistor nyob rau hauv nrog cov twj tso zis. Tau kawg, qhov no tau ua txhaum 1-rau-10 qhov tsawg kawg nkaus ntawm cov khoom tawm tuaj rau kev xav tias qhov kev nkag siab ntawm qhov peb tau tham saum toj no, thiab yog li muaj qhov cuam tshuam ntau zaus ntawm cov lus hais txuas lus, tab sis qhov ntawd yog yam koj tau txais nrog ntau lub raj amps thiab nws yog raws nraim li cas Carver xav simulate.
02 ntawm 03
Preamp / Qhov Chaw Ntaus Tawm Tso Zis Impedance
Nrog lub preamp los yog qhov khoom siv (CD player, cable box, thiab lwm yam), raws li muaj hauv daim duab saum toj no, nws yog ib qho xwm txheej txawv. Hauv qhov no, koj tsis quav ntsej txog lub hwj chim los yog tam sim no. Txhua yam koj yuav tsum qhia txog lub teeb liab ntawm lub suab yog qhov voltage. Yog li, cov nqes hluav taws xob - lub hwj huam tuaj, tus txheej txheem ntawm lub preamp, los yog ib lub preamp, thaum muaj ib qho chaw siv khoom - tuaj yeem muaj kev tawm tswv yim siab. Ib qho tam sim no los ntawm txoj kab yog yuav luag tag nrho los ntawm qhov kev nkag siab siab impedance, tab sis qhov voltage tau los ntawm kev nplua xwb.
Rau feem ntau lub fais fab amps thiab preamps, ib qho kev tawm tsam impedance ntawm 10 mus rau 100 kilohms yog ntau. Engineers tau mus siab, tab sis lawv yuav tau txais ntau lub suab nrov ntawd. Incidentally, guitar amps feem ntau muaj peev xwm impedances ntawm 250 kilohms rau 1 megohm, vim electric guitar pickups feem ntau muaj tso tawm impedances xws li 3 mus 10 kilohms.
Short circuits muaj peev xwm ua tau nrog cov kab hauv theem, vim tias nws yooj yim heev rau qhov ob tus neeg liab qab ntawm RCA ntsaws tiv thaiv ib daim hlau uas luv lawv tawm. Yog li, tso tawm impedances ntawm 100 ohms los yog ntau dua hauv cov preamps thiab cov khoom siv. Kuv pom ob peb kab txawv, high-end Cheebtsam nrog cov kab tawm hauv qib uas muaj tsawg li 2 ohms, tab sis cov no yuav muaj cov khoom lag luam uas muaj hnyav dhau los lossis ib qho kev tivthaiv kom tiv thaiv kev puas tsuaj tawm. Muaj qee zaum, lawv muaj peev xwm muaj qhov sib txuas ua lag luam ntawm tus tso tawm mus rau DC voltage thiab tiv thaiv cov khoom siv hluav taws xob.
Phono preamps yog ib qho kev kawm sib txawv nkaus xwb. Thaum lawv feem ntau muaj cov kev tso tawm impedances zoo ib yam li cov neeg ntawm CD player, lawv cov tswv yim impedances ntau heev los ntawm cov neeg uas muaj kab-theem preamp. Tias 's ntau dhau mus rau hauv no. Tej zaum kuv yuav khawb rau hauv qhov kev kawm no hauv lwm tsab xov xwm.
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Lub mloog pob ntseg Amp Output Impedance
Kev cia siab nyob rau hauv tej chaw ntawm lub pob ntseg tau coj qhov kev weird theej, tsis yog-tus qauv system impedance ntawm kev kho lub ntsej muag lub pob ntseg rau lub tsom teeb. Tsis zoo li cov pa amps, lub mloog pob ntseg mloog amps tuaj rau ntau yam kev tawm dag zog. Cov khoom lag luam impedance feem ntau yog li ntawm 16 mus rau 70 ohms.
Nws tsis tshua zoo rau tus neeg tau txais kev tshem tawm thiab rov tham cov neeg sib tham thaum tus amp khiav, thiab kuj tsis tshua muaj cov lus qhia cables kom raug thaum ib tus amp khiav. Tiam sis nrog lub mloog pob ntseg, tej yam no tshwm sim txhua lub sijhawm. Tib neeg niaj hnub txuas los sis tshem tawm thaum lub mloog pob ntseg nrov. Headphone cables feem ntau puas ntsoog - tej zaum tsim lub luv Circuit Court - thaum lawv siv. Ntawm chav kawm, feem ntau lub mloog pob ntseg amps yog pheej yig twj, uas tuaj yeem muab ntxiv ib qho kev tiv thaiv kev tiv thaiv ncaj ncees-tsis txwv. Yog li feem ntau manufacturers tau yooj yim txoj kev tawm: Lawv nce cov zis impedance ntawm lub amplifier los ntawm kev ntxiv ib resistor (los yog puav ib capacitor).
Raws li koj tau pom hauv kuv lub pob ntseg ntawm tes (nce mus rau qhov thib ob teeb), siab tso tawm impedance muaj peev xwm muaj kev cuam tshuam loj heev rau cov lus teb ntawm lub mloog pob ntseg. Kuv ntsuas cov lus teb ntawm lub mloog pob ntseg ua ntej nrog lub suab paj nruas Fidelity lub mloog pob ntseg amp uas muaj 5-ohm tso tawm impedance, ces dua nrog ib qho ntxiv 70 ohms ntawm kev ua hauj lwm ntxiv rau tsim tawm tag nrho cov zis impedance ntawm 75 ohms.
Cov nyhuv uas muaj siab tso tawm impedance yuav txawv nrog lub impedance ntawm lub ntsej muag connected, thiab tshwj xeeb tshaj yog nrog cov kev hloov hauv lub pob ntseg ntawm lub pob ntseg ntawm txawv frequencies. Headphones uas muaj ntau lub suab voj voog - raws li feem ntau ntawm cov qauv hauv lub pob ntseg nrog cov neeg tsav tsheb uas muaj peev xwm ua tau - feem ntau yuav muaj cov kev hloov pauv ntawm cov lus teb thaum koj hloov ntawm tus amp nrog cov zis tawm impedance mus rau ib qho uas muaj cov zis impedance. Feem ntau, ib lub mloog pob ntseg uas muaj lub suab sib npaug zos thaum lub sij hawm siv nrog tsawg-impedance qhov chaw yuav muaj bassy, npau-sounding tshuav nyiaj thaum siv nrog qhov chaw siab-impedance.
Zoo hmoo, low output impedance yog muaj nyob rau hauv ntau lub high-end lub mloog pob ntseg amps (tshwj xeeb yog lub xeev-lub cev qauv), thiab txawm tias ib txhia me ntsis lub mloog pob ntseg amp chips ua rau hauv xws li iPhones. Muaj feem ntau tsis muaj txoj hau kev kom paub meej tias lub mloog pob ntseg yog siv rau kev siv lub siab los yog tsis tshua muaj tso tawm impedances, tab sis kuv xav los lo nrog tsawg tawm impedance rau vim li cas muab teev rau hauv tsab xov xwm no.
Kuv xav kom tsis txhob siv cov headphones nrog loj impedance viav vias uas yuav ua rau cov lus teb hloov thaum siv nrog lub mloog pob ntseg amps uas muaj siab tso tawm impedance (xws li hauv ib lub laptop Kuv tabtom ntaus ntawv no). Txawm li cas los xij, kuv pheej xav tias lub suab ntawm qhov zoo sib xws-hauv lub pob ntseg pob ntseg rau ib qho uas siv tsav tsav tsheb, yog li thaum kuv siv cov headphones nrog kuv lub laptop, kuv nquag txuas ib qho ntxiv amp lossis USB lub mloog pob ntseg amp / DAC.
Kuv paub tias qhov no yog ib lub ntsiab lus ntev ntev, tiam sis kev tso tawm impedance yog lub ntsiab lus nyuab. Tsaug rau kev coj tus kheej nrog kuv, thiab yog tias koj muaj lus nug lossis yog tias kuv tawm ib yam dab tsi, xa kuv tus e-mail thiab qhia rau kuv paub.