Tej yam yooj yim amplifier transistors los ntawm txhais tes. Amplifier rau ib tug hluas transistor: lub tswvyim

Amplifier transistors, txawm nws twb ntev keeb kwm, yog ib tug nyiam kawm ntawm txoj kev tshawb no, beginners thiab venerable hams. Thiab qhov no yog to taub. Nws yog ib qho tseem ceeb ib feem ntawm feem ntau loj amateur xov tooj cua kiag li lawm: xov tooj cua receivers thiab amplifiers nyob rau hauv tsawg (sonic) zaus. Peb saib yuav ua li cas los tsim kom tau tej yam yooj yim amplifiers tsawg zaus transistors.

Lub zaus teb ntawm tus amplifier

Nyob rau hauv txhua TV los yog xov tooj cua, nyob rau hauv txhua txhua cov suab paj nruas chaw los yog amplifier transistor yuav nrhiav tau lub suab amplifiers (tsawg zaus - LF). Qhov txawv ntawm cov suab transistor amplifiers thiab lwm yam yog lawv zaus yam ntxwv.

Suab amplifier transistors muaj tiaj zaus teb nyob rau hauv lub zaus band los ntawm 15 Hz mus rau 20 kHz. Qhov no txhais tau tias tag nrho cov tswv yim Pib ntsais koj teeb nrog ib zaus li no ntau, lub amplifier converts (nce) kwv yees li sib npaug. Tus naj npawb hauv qab no qhia tau hais tias ib lub "nce amplifier Ku - Tswv yim zaus" nkhaus qhia tau hais tias ib qho zoo tagnrho zaus yam ntxwv rau ib tug suab amplifier.

Qhov no nkhaus yog yuav luag tiaj los ntawm 15 Hz mus rau 20 kHz. Qhov no txhais tau hais tias thov ib lub hwj chim yuav precisely tswv yim Pib ntsais koj teeb nrog frequencies ntawm 15 Hz thiab 20 kHz. Rau cov tswv yim Pib ntsais koj teeb nrog frequencies saum toj no 20 kHz thiab hauv qab no 15 Hz efficiency thiab zoo ntawm nws ua hauj lwm sai heev txo.

Hom zaus cov yam ntxwv ntawm cov amplifier yog txiav txim los ntawm lub tshuab hluav taws xob Cheebtsam (Ere) ntawm nws cov Circuit Court, feem ntau transistors lawv tus kheej. Suab amplifier transistors feem ntau tuaj txoos ua ke nyob rau hauv thiaj li hu ua tsawg thiab nruab nrab zaus transistor nrog ib tug tag nrho bandwidth ntawm cov tswv yim Pib ntsais koj teeb ntawm kaum thiab pua pua ntawm Hz mus rau 30 kHz.

kawm ua hauj lwm amplifier

Raws li nws yog lub npe hu, nyob ntawm seb cov neeg kawm ntawv ntawm saab laaj ntawm tam sim no txaus thaum lub sij hawm lub sij hawm nws los ntawm transistor amplifier theem (amplifier) paub qhov txawv nws lub lag luam raws li nram no cov chav kawm: "A", "B", "AB", "C", "D".

Nyob rau hauv lub lag luam tam sim no hauv chav kawm ntawv "A" ntws los ntawm ib tug cascade tshaj ib tug 100% tswv yim teeb liab lub sij hawm. cascade ua hauj lwm nyob rau hauv cov hoob kawm no tom ntej no qhia txog cov kev kos duab.

Nyob rau hauv lub chav kawm ntawv ntawm lub lag luam ntawm lub amplifier theem "AB" tam sim no tsev therethrough ntau tshaj 50% tab sis tsawg tshaj 100% ntawm cov tswv yim lub sij hawm (saib. Daim duab hauv qab no).

Nyob rau hauv ib chav kawm ntawv ntawm cascade "B" tam sim no tsev therethrough raws nraim 50% ntawm cov tswv yim teeb liab lub sij hawm, raws li qhov lus piv txwv nyob rau hauv daim duab.

Thiab thaum kawg nyob rau hauv lub chav kawm ntawv ntawm cascade "C" tam sim no ntws therethrough nyob hauv tsawg tshaj 50% ntawm cov tswv yim teeb liab lub sij hawm.

LF amplifier transistors: loj distortions nyob rau hauv lub chav kawm ntawv ua hauj lwm

Nyob rau hauv lub teb ntawm transistor amplifier kev khiav hauj lwm cov chav kawm ntawv "A" muaj ib tug uas tsis muaj theem ntawm harmonic distortion. Tab sis, yog hais tias lub teeb liab muaj ib tug voltage mem tes emissions, ua rau kev tsuas xyaus ntawm cov transistors, lub siab dua harmonics (mus txog rau 11 feeb) tshwm sim nyob ib ncig ntawm txhua "tsis tu ncua" harmonic tso zis. Qhov no ua rau tshwm sim ntawm lub thiaj li hu ua transistor, los yog ib tug nws yog xim hlau suab.

Yog hais tias hwj chim amplifiers LF transistors muaj unregulated lub hwj chim, lawv tso zis Pib ntsais koj teeb modulated nyob rau hauv amplitude nyob ze rau qhov mains zaus. Qhov no ua rau cov rigidity ntawm lub suab nyob rau sab laug ntawm ntug zaus teb. Ntau txoj kev rau cov stabilization ntawm lub voltage amplifier ua rau cov tsim ntau.

Raug efficiency ib tas hoob A amplifier tsis pub tshaj 20% vim lub lossi qhib transistor thiab ib tug tas mus khiav ntawm ib qhov tam sim no kev tivthaiv. Koj muaj peev xwm ua tau ib tug hauv chav kawm ntawv Ib tug laub-rub amplifier, lub efficiency yuav ua rau kom dog dig, tab sis ib nrab-yoj teeb liab yuav muaj ntau kauj. Neeg txhais lus ntawm cov theem ntawm lub chaw ua hauj lwm ntawm cov chav kawm ntawv "A" nyob rau hauv lub chav kawm ntawv ua hauj lwm "AB" nce fourfold harmonic distortion, tab sis tus ua hauj lwm zoo ntawm nws cov tswvyim nyob rau hauv cov ntaub ntawv no yog nce.

Nyob rau hauv amplifiers tib chav kawm ntawv "AB" thiab "B" distortions kom raws li lub teeb liab theem yuav txo tau. Involuntarily kerf xav tau ib tug louder amp mus ua kom tiav cov nov ntawm nqaij tawv ntawm lub hwj chim thiab muaj zog ntawm cov suab paj nruag, tab sis feem ntau nws tsis pab.

Intermediate chav kawm ntawv ua hauj lwm

Nyob rau hauv kev ua hauj lwm hauv chav kawm ntawv "A" muaj ib tug zoo ntawm - chav kawm ntawv "A +". Yog li, tsawg-voltage tswv yim transistors ntawm no hauv chav kawm ntawv amplifier ua hauj lwm nyob rau hauv chav kawm ntawv "A" thiab cov high-voltage tso zis transistors ntawm lub amplifier yog ua zoo tshaj thaum lawv lub tswv yim Pib ntsais koj teeb mus ib theem nyob rau hauv lub chav kawm ntawv "V" los yog "AB". Nqi ntawm xws cascades zoo dua ntshiab chav kawm ntawv "A", thaum nonlinear distortion tsawg (0.003%). Txawm li cas los, lawv kuj suab "nws yog xim hlau" vim lub xub ntiag ntawm ntau dua harmonics nyob rau hauv lub tso zis teeb liab.

Nyob rau hauv lwm chav kawm ntawv ntawm amplifiers - "AA" theem ntawm harmonic distortion yog txawm tsawg - txog 0,0005%, tab sis ntau harmonics yog tseem tam sim no.

Rov qab mus rau cov transistor amplifier ntawm cov chav kawm ntawv "A"?

Niaj hnub no, cov kws txawj nyob rau hauv lub teb ntawm high-zoo suab tu tub tu kiv tus thoob tswv yim ib tug rov qab mus rau lub raj amplifiers, txij thaum lub theem ntawm harmonic distortion thiab harmonics qhia los ntawm lawv mus rau hauv ib tug tso zis teeb liab, obviously qis dua cov transistors. Txawm li cas los, cov zoo yog offset los ntawm ib tug loj raws li qhov xav tau ntawm cov txuam transformer ntawm lub siab kuj raj tso zis theem thiab tsawg impedance suab hais lus. Txawm li cas los, tej yam yooj yim thiab lub hwj chim transistors yuav tau nrog ib tug transformer tso zis, raws li yuav tsum tau qhia rau hauv qab no.

Muaj kuj yog ib tug saib hais tias qhov kawg suab zoo yuav tsuas yog muab ib tug hybrid raj-transistor amplifier, tag nrho cov uas yog tib-cycle theem tsis them los ntawm lub zoo tswv yim , thiab ua hauj lwm nyob rau hauv ib chav kawm ntawv "A". Hais tias yog, ib tug repeater yog ib lub hwj chim amplifier rau ib tug hluas transistor. Lub Circuit Court zaum yuav muaj nws tshaj plaws attainable efficiency (nyob rau hauv lub chav kawm ntawv "A") yog tsis ntau tshaj li 50%. Tab sis tsis lub hwj chim los yog lub amplifier efficiency yog indicative ntawm qhov zoo tshaj ntawm lub suab tu tub tu kiv. Kev tseem ceeb hniav mus rau qhov zoo thiab linearity ntawm Ere nyob rau hauv lub Circuit Court.

Txij li thaum ib leeg-twb circuits yog xws li ib tug kev xav, peb xav txog hauv qab no lawv possibilities.

Ib leeg-tas amplifier rau ib tug hluas transistor

Scheme nws, tau nrog ib tug ntau emitter thiab RC-bonds rau lub tswv yim thiab tso zis Pib ntsais koj teeb rau cov chav kawm ntawv "A" yog li nram qab no.

Muaj yog muaj ib tug transistor Q1 npn qauv. Nws collector ntawm ib tug tam sim no txawj resistor R3 yog kev cob cog rua rau lub zoo davhlau ya nyob twg + Vcc, thiab ib tug emitter - mus -Vcc. Fais fab transistor pnp qauv yuav muaj tib lub Circuit Court, tab sis lub hwj huam mov terminals swapped.

C1 - thaiv cov hlab capacitor, whereby lub AC tswv yim teeb liab yog cais los ntawm lub DC voltage Vcc. Nyob rau hauv cov ntaub ntawv no, C1 tsis tiv thaiv kom txhob tso cai ntawm lub AC tswv yim tam sim no los ntawm lub hlws ris "hauv paus - Q1 transistor emitter." Resistors R1 thiab R2 ua ke nrog rau cov kev hloov kuj "E - B" tsim ib tug voltage divider Vcc mus xaiv tus khiav hauj lwm point ntawm lub transistor Q1 nyob rau hauv qhov zoo li qub hom. Raug rau no Circuit Court yog tus nqi ntawm R2 = 1 kohm, thiab txoj hauj lwm ntawm lub operating point - Vcc / 2. R3 yog lub load resistor thiab cov collector Circuit Court yog siv los tsim cov collector AC tso zis voltage.

Piv txwv tias yog hais tias Vcc = 20 V, R2 = 1 kohm, thiab tam sim no amplification tshaj h = 150. Tus voltage rau lub emitter ntawm xaiv Lwm = 9 V, thiab cov voltage nco thoob plaws lub hlws ris "E - B" yog lam xav sib npaug zos rau Vbe = 0,7 V. qhov no tus nqi sau raws nkaus Ii lub thiaj li hu ua silicon transistors. Yog hais tias peb pom tias cov amplifier rau germanium transistors, lub voltage nco nyob rau qhib kev hloov "E - B" yuav ua ncaj rau Vbe = 0,3 V.

emitter tam sim no yog kwv yees li sib npaug zos rau qhov tam sim no collector

Xws li = 9 B / 1 k = 9 ma ≈ IC.

Base tam sim no Ib = IC / h = 9 MA / 150 = 60 Ua.

Lub voltage nco thoob plaws lub resistor R1

V (R1) = Vcc - VB = Vcc - (Vbe + Lwm) = 20 V - 9.7 V = 10.3 V,

R1 = V (R1) / Ib = 10,3 V / 60 MA = 172 Ohm.

C2 yog yuav tsum tau mus tsim ib cov saw dua lub AC feem ntawm cov emitter (collector tam sim no ua tau). Yog hais tias nws tsis yog, ces tus resistor R2 yog xav txwv mus rau lub AC tivthaiv, yog li ntawd qhov kev kawm hwj chim bipolar transistor yuav muaj ib tug tsis tshua muaj tam sim no tau.

Nyob rau hauv peb suav peb lam xav tias IC = Ib h, qhov twg Ib - puag tam sim no ntws mus rau hauv nws los ntawm cov emitter thiab tshwm sim thaum ua ntawv thov mus rau lub kev tsis ncaj ncees hauv paus. Txawm li cas los, yeej ib txwm los ntawm lub puag (raws li nyob rau hauv lub xub ntiag ntawm xaav, thiab tsis muaj nws) hais ntau thiab ib tug to tam sim no ntawm Icb0 collector. Yog li ntawd, qhov tiag collector tam sim no yog IC = Ib h + Icb0 h, i.e. to tam sim no nyob rau hauv ib tug Circuit Court nrog lub MA amplified 150 lub sij hawm. Yog hais tias peb pom tias cov amplifier rau germanium transistors, qhov no fact yuav tsum raug coj mus rau hauv tus account nyob rau hauv cov lus teb. Lub fact tias cov germanium transistors muaj ib tug tseem ceeb Icb0 kev txiav txim ntawm ib tug ob peb microamps. Nyob rau hauv pob zeb ntais, nws peb kev txiav txim ntawm qhov ntau me me thiab (hais txog ob peb tam sim no), yog li ntawd lawv feem ntau tsis quav ntsej li nyob rau hauv cov lus teb.

Ib leeg-tas amplifier nrog hlis-transistor

Raws li cov kev amplifier FET, suav hais tias lub tswvyim nws muaj nws txoj kev counterpart ntawm cov amplifiers rau bipolar transistors. Yog li ntawd, peb xav txog yav dhau los analog circuits nrog ib qho emitter. Nws yog tsim los ntawm ib qho qhov twg los thiab RC-bonds rau lub tswv yim thiab tso zis Pib ntsais koj teeb rau cov chav kawm ntawv "A" thiab nws tau qhia rau hauv qab no.

Muaj C1 - ib tug thaiv cov hlab capacitor, whereby lub AC tswv yim teeb liab yog cais los ntawm lub DC voltage Vdd. Raws li yog lub npe hu, tej amplifier FET yuav tsum muaj ib tug qhov rooj tej zaum ntawm nws mis transistors hauv qab no lawv tej chaw. Nyob rau hauv no Circuit Court lub rooj vag yog grounded resistor R1, muaj feem ntau yog ib tug siab kuj (100 kOhm mus rau 1 MOhm), nws tsis yog shunted mus rau lub tswv yim lub teeb liab. Tus tam sim no los ntawm R1 yog yuav luag tsis dhau, li ntawd, lub rooj vag tej zaum thaum tsis muaj tswv yim teeb liab yog sib npaug zos rau cov av tej zaum. Lub peev xwm ntawm qhov chaw saum toj no hauv pem teb tej zaum vim cov voltage nco thoob plaws lub resistor R2. Yog li, lub rooj vag peev xwm yog qis dua qhov muaj peev xwm, uas yog tsim nyog rau ib txwm lag luam ntawm Q1. Lub capacitor C2 thiab lub resistor R3 muaj tib lub muaj nuj nqi raws li nyob rau hauv lub yav dhau los tswvyim. Vim qhov no Circuit Court nrog ib qho qhov twg los, ces lub tswv yim thiab tso zis Pib ntsais koj teeb yog theem txav los ntawm 180 °.

Amplifier nrog transformer tso zis

Ib tug thib peb yooj yim one-theem amplifier transistors qhia nyob rau hauv daim duab hauv qab no, yog tseem configured ntawm cov-emitter rau koj khiav lag luam nyob rau hauv lub chav kawm ntawv "A", tab sis nrog ib tug tsawg impedance hais lus nws yog kev cob cog rua ntawm ib txoj kev transformer.

Lub hom winding ntawm transformer T1 yog lub load ntawm lub collector ntawm transistor Q1 thiab Circuit Court muaj ib tug tso zis teeb liab. T1 hau ib zis teeb liab mus rau ib tug hais lus, thiab muab ua kom tiav kom sib haum tso zis transistor nrog tsawg kuj (txog ob peb ohms) impedance hais lus.

Voltage divider collector hwj chim qhov twg los Vcc sau resistors R1 thiab R3, muab cov kev xaiv ntawm cov kev khiav hauj lwm point ntawm lub transistor Q1 (lub kev tsis ncaj ncees voltage rau nws puag). Sij hawm ntawm qhov seem uas hais txog qhov amplifier yog tib yam li nyob rau hauv lub yav dhau los schemes.

Lub laub-rub suab amplifier

Laub rub amplifier LF ob transistors splits lub tswv yim lub teeb liab zaus los ntawm ob antiphase ib nrab-yoj, txhua tus uas yog kho kom zoo los ntawm nws tus kheej transistor theem. Tom qab ua tau zoo xws li ib tug ib nrab-yoj amplification ua ke rau hauv ib harmonic teeb liab, uas yog kis tau mus rau cov lus qhia system. Xws li ib tug tsawg zaus teeb liab hloov dua siab tshiab (splitting thiab re-phiajcim) lawm ua irreversible distortions nyob rau ntawd vim qhov txawv ntawm qhov zaus thiab dynamic thaj chaw ntawm lub ob transistor circuits. Cov distortions txo suab zoo nyob rau amplifier tso zis.

Push-pull amplifier kev khiav hauj lwm nyob rau hauv lub chav kawm ntawv "A" tsis zoo me nyuam lub complex suab Pib ntsais koj teeb, raws li ib tug qhov tam sim no tus nqi yog nce tsis tu ncua ntws mus rau hauv lawv lub xub pwg nyom. Qhov no leads mus rau ib Unbalance ntawm ib nrab tsis teeb liab, theem distortion thiab thaum kawg rau hauv lub poob ntawm intelligibility ntawm lub suab. Los ntawm cov cua kub, ob hwj chim transistors yog nce ob zaug nyob rau hauv cov uas tsis muaj distortion thiab cov subsonic zaus teeb liab. Txawm li cas los, lub ntsiab kom zoo dua ntawm lub laub-rub Circuit Court yog nws tau ua hauj lwm zoo thiab muaj zog tso zis ntau zog.

Laub rub hwj chim amplifier Circuit Court nrog transistors yog qhia nyob rau hauv Daim duab.

Qhov no amplifier ua hauj lwm nyob rau hauv chav kawm ntawv "A", tab sis yuav siv tau thiab cov chav kawm "AB", thiab txawm "B".

Transformerless hwj chim amplifier transistor

Transformers, dua li cov kev kawm nyob rau hauv lawv cov miniaturization yog tag nrho cov tib loj, hnyav thiab kim Ere. Yog li ntawd, nws twb pom ib tug txoj kev los mus tshem tawm cov transformer ntawm lub laub-rub Circuit Court los ntawm executing nws rau ob tug haib complementary transistors ntawm ntau hom (npn thiab pnp). Feem ntau cov niaj hnub hwj chim amplifiers siv txoj ntsiab cai no thiab yog tsim los ua hauj lwm nyob rau hauv chav kawm ntawv "B". Daim duab ntawm xws li ib tug hwj chim amplifier yog qhia hauv qab no.

Ob leeg nws transistor cov txheej txheem raws li ntau-collector (emitter follower). Yog li ntawd, rau hauv Circuit Court kis lub tswv yim voltage rau cov qhov tso zis tsis muaj amplification. Yog hais tias lub tswv yim teeb liab yog tsis tam sim no, ob qho tib si transistors yog nyob rau hauv tus ciam ntawm lub on-lub xeev, tab sis lawv yog muab tua.

Thaum lub harmonic teeb liab yog inputted, nws yuav qhib qhov zoo ib nrab-yoj TR1, tab sis xav tau kev pab pnp TR2 transistor siab nyob rau hauv cutoff hom. Yog li, tsuas yog tus zoo ib nrab-Nthwv dej no muaj amplified tam sim no tsev los ntawm lub load. Cov tsis zoo ib nrab-yoj tswv yim teeb liab qhib xwb muab kaw TR2 thiab TR1, yog li ntawd lub load hwj chim nkag mus hauv lub tsis zoo ib nrab-yoj tam sim no. Raws li ib tug tshwm sim, lub load yog tso tawm rau tag nrho cov hwj chim nce (vim tam sim no amplification) sinusoidal teeb liab.

Amplifier rau ib tug hluas transistor

Rau lub assimilation ntawm cov foregoing sib sau ua ke yooj yim amplifier transistors nrog lawv ob txhais tes thiab saib yuav ua li cas nws ua hauj lwm.

Nyob rau hauv muaj nyob rau hauv qhov yooj yim Circuit Court T. Yuav pub uas tsis muaj zog Circuit Court raws li ib tug load transistor BC107 hom T nrog headsets nrog ib tug tsis kam ntawm 2-3 ohms, ib tug tsis ncaj ncees voltage rau lub hauv paus yuav muab ib tug siab kuj nqi resistor R * 1 MOhm, lub decoupling capacitance electrolytic capacitor C ntawm 10 microfarads 100 microfarads yuav roj teeb 4.5V / 0.3 AA

Yog hais tias lub resistor R * yog tsis cob cog rua, tsis muaj lub hauv paus tam sim no Ib los yog IC ntawm qhov tam sim no collector. Yog hais tias lub resistor yog kev cob cog rua, cov voltage rau hauv lub hauv paus ntawm lub nce mus 0.7 V, thiab los ntawm nws ntws ib tug tam sim no Ib = 4 ma. Tus tam sim no nce ntawm transistor 250 yog sib npaug zos rau muab IC = 250Ib = 1 ma.

Coj ib tug neeg yooj yim amplifier transistors nrog lawv tus kheej txhais tes, peb muaj peev xwm tam sim no ua nws. Ntsaws rau hauv koj lub headphones thiab muab tso rau koj ntiv tes rau ntawm tus taw tes 1 ntawm lub Circuit Court. Koj yuav hnov ib lub suab nrov. Koj lub cev perceives tawg mains mov ntawm ib zaus ntawm 50 Hz. Lub suab nrov koj hnov los ntawm cov headphones, thiab qhov no tawg tsuas yog hwj chim transistor. Cia peb piav qhia txog tus txheej txheem no nyob rau hauv ntau yam. AC voltage nrog ib zaus ntawm 50 Hz yog kev cob cog rua rau lub hauv paus ntawm lub transistor ntawm ib tug capacitor C. Lub voltage rau lub hauv paus yog tam sim no sib npaug zos rau cov sum ntawm cov DC kev tsis ncaj ncees voltage (kwv yees li 0.7 V), los ntawm lub resistor R *, thiab ib tug AC voltage "los ntawm cov ntiv tes." Raws li ib tug tshwm sim, lub collector tam sim no tau txais los ntawm lub AC tivthaiv zaus ntawm 50 Hz. Qhov no alternating tam sim no yog siv los mus ua hauj lwm ceev cov lus qhia diaphragm yuj yees nrog tib zaus, uas txhais tau tias peb yuav tau hnov lub suab nrov ntawm 50 Hz tso zis.

Ua si 50 Hz suab nrov yog tsis heev exciting, li ntawd, yuav tsum tau txuas mus rau lub ntsiab lus 1 thiab 2, lub tsawg zaus teeb liab qhov chaw (CD-neeg uas ua ntawv los yog microphone) thiab enhanced hnov ​​hais lus los yog cov suab paj nruag.