Lub tshuab hluav taws xob transistor, txawm hais tias nws twb muaj keeb kwm ntev lawm, tseem yog ib qho kev nyiam ntawm kev kawm rau ob qho tib si pib thiab cov qub tub rog amateurs. Thiab qhov no yog to taub. Nws yog ib qho tseem ceeb ntawm cov khoom siv hauv xov tooj cua nrov tshaj plaws: xov tooj cua receivers thiab low (sound) zaus amplifiers. Peb yuav saib seb qhov yooj yim tshaj plaws low-frequency transistor amplifiers tsim.
Amp zaus teb
Hauv txhua lub xov tooj cua lossis xov tooj cua, hauv txhua lub chaw suab paj nruag lossis lub suab nrov nrov, koj tuaj yeem nrhiav transistor suab amplifiers (tsawg zaus - LF). Qhov txawv ntawm lub suab transistor amplifiers thiab lwm yam nyob rau hauv lawv zaus teb.
Lub transistor audio amplifier muaj cov lus teb tsis sib xws hauv cov zaus zaus ntawm 15 Hz txog 20 kHz. Qhov no txhais tau hais tias tag nrho cov input signals nrog ib tug zaus nyob rau hauv no ntau yam yog hloov dua siab tshiab (amplified) los ntawm lub amplifier.txog ib yam. Daim duab hauv qab no qhia txog qhov zoo tshaj plaws zaus teb nkhaus rau lub suab amplifier hauv kev tswj xyuas "amplifier nce Ku - input signal zaus".
Qhov nkhaus no yuav luag tiaj tus ntawm 15Hz txog 20kHz. Qhov no txhais tau hais tias xws li amplifier yuav tsum tau siv tshwj xeeb rau input signals nrog zaus ntawm 15 Hz thiab 20 kHz. Rau input signals nrog frequencies saum 20 kHz los yog qis dua 15 Hz, nws efficiency thiab kev ua tau zoo deteriorate sai.
Hom zaus teb ntawm lub amplifier yog txiav txim siab los ntawm cov hluav taws xob xov tooj cua (ERE) ntawm nws lub voj voog, thiab qhov tseem ceeb tshaj plaws los ntawm cov transistors lawv tus kheej. Lub suab amplifier raws li cov transistors feem ntau yog sib sau ua ke ntawm qhov hu ua low- thiab nruab nrab zaus transistors nrog tag nrho bandwidth ntawm cov tswv yim tawm tswv yim los ntawm kaum thiab pua pua Hz txog 30 kHz.
Amplifier class
Raws li koj paub, nyob ntawm qib ntawm kev txuas ntxiv ntawm cov dej ntws tam sim no thoob plaws hauv nws lub sijhawm dhau los ntawm transistor amplifying theem (amplifier), cov chav kawm hauv qab no ntawm nws txoj haujlwm tau txawv: "A", "B", "AB", "C", "D".
Nyob rau hauv chav kawm ntawm kev ua haujlwm, tam sim no "A" ntws los ntawm theem rau 100% ntawm lub sijhawm teeb liab tawm tswv yim. Lub cascade nyob rau hauv chav kawm no yog qhia hauv daim duab hauv qab no.
Nyob hauv chav kawm "AB" amplifier theem, tam sim no ntws los ntawm nws ntau dua 50%, tab sis tsawg dua 100% ntawm lub sijhawm ntawm lub teeb liab tawm tswv yim (saib daim duab hauv qab no).
Nyob rau hauv chav kawm ntawm kev ua haujlwm ntawm theem "B", qhov tam sim no ntws los ntawm nws raws nraim 50% ntawm lub sijhawm ntawm lub teeb liab tawm tswv yim, raws li tau piav qhia hauv daim duab.
Thaum kawg, hauv "C" theem ua haujlwm chav kawm, qhov tam sim no ntws los ntawm nws tsawg dua 50% ntawm lub sijhawm teeb tsa lub tswv yim.
LF-transistor amplifier: distortion hauv cov chav kawm tseem ceeb ntawm kev ua haujlwm
Hauv thaj chaw ua haujlwm, chav kawm "A" transistor amplifier muaj qib qis ntawm qhov tsis sib xws. Tab sis yog hais tias lub teeb liab muaj impulse surges nyob rau hauv voltage, ua rau saturation ntawm lub transistors, ces siab dua harmonics (txog 11th) tshwm sim nyob ib ncig ntawm txhua "standard" harmonic ntawm cov zis teeb liab. Qhov no ua rau qhov tshwm sim ntawm lub suab hu ua transistorized lossis metallic suab.
Yog tias lub hwj chim qis qis ntawm cov transistors muaj lub zog tsis ruaj khov, ces lawv cov teeb liab tso tawm tau hloov kho hauv amplitude ze ntawm lub mains zaus. Qhov no ua rau hnyav ntawm lub suab ntawm sab laug ntug ntawm cov lus teb zaus. Ntau yam kev ruaj ntseg hluav taws xob ua rau tus tsim ntawm lub amplifier complex.
Kev ua tau zoo ntawm ib leeg-kawg Class A amplifier tsis pub tshaj 20% vim yog lub transistor ib txwm muaj thiab qhov tsis tu ncua ntawm DC tivthaiv. Koj tuaj yeem ua rau chav kawm A amplifier thawb-rub, qhov ua tau zoo yuav nce me ntsis, tab sis ib nrab nthwv dej ntawm lub teeb liab yuav dhau los ua asymmetric. Kev hloov pauv ntawm cov cascade los ntawm chav ua haujlwm "A" mus rau chav ua haujlwm "AB" quadruples lub nonlinear distortion, txawm hais tias qhov ua tau zoo ntawm nws lub voj voog nce.
Bamplifiers ntawm chav kawm "AB" thiab "B" distortion nce raws li lub teeb liab theem txo. Koj tsis yeem xav tig lub suab nrov nrov rau qhov kev xav ntawm lub zog thiab lub zog ntawm lub suab paj nruag, tab sis feem ntau qhov no tsis pab ntau.
chav kawm haujlwm nruab nrab
chav haujlwm "A" muaj qhov hloov pauv - chav kawm "A+". Nyob rau hauv cov ntaub ntawv no, lub low-voltage input transistors ntawm amplifier chav kawm ntawv no ua hauj lwm nyob rau hauv chav kawm ntawv "A", thiab high-voltage output transistors ntawm lub amplifier, thaum lawv input signals tshaj ib theem, mus rau hauv chav kawm ntawv "B" los yog "AB". Kev ua tau zoo ntawm cov cascades zoo dua li hauv chav kawm dawb "A", thiab qhov tsis yog-linear distortion tsawg (txog 0.003%). Txawm li cas los xij, lawv kuj suab "hloov" vim tias muaj kev sib haum xeeb siab dua hauv cov teeb liab tso zis.
Amplifiers ntawm lwm chav kawm - "AA" muaj txawm tias qis dua ntawm qhov tsis yog-linear distortion - txog 0.0005%, tab sis siab dua harmonics kuj tseem muaj.
Rov qab mus rau Chav A transistor amplifier?
Hnub no, ntau tus kws tshaj lij hauv kev ua haujlwm ntawm cov suab nrov zoo tshaj tawm tus neeg tawm suab rov qab mus rau lub raj amplifiers, txij li theem ntawm kev tsis sib haum xeeb thiab kev sib raug zoo siab dua tau qhia los ntawm lawv rau hauv cov teeb liab tso tawm yog pom tseeb qis dua li ntawm transistors.. Txawm li cas los xij, cov txiaj ntsig zoo no feem ntau cuam tshuam los ntawm qhov xav tau ntawm kev sib hloov pauv ntawm lub siab-impedance raj tso zis theem thiab cov neeg hais lus qis impedance. Txawm li cas los xij, ib qho yooj yim transistorized amplifier tuaj yeem ua nrog lub tshuab hluav taws xob tso tawm raws li qhia hauv qab no.
Tseem muaj lub ntsiab lus pom tias tsuas yog hybrid tube-transistor amplifier tuaj yeem muab lub suab zoo kawg nkaus, txhua theem ntawm ib leeg-kawg, tsis suav nrog kev tawm tswv yim tsis zoo thiab ua haujlwm hauv chav kawm "A". Ntawd yog, xws li lub zog ua raws li lub suab nrov ntawm ib qho transistor. Nws cov tswv yim tuaj yeem muaj qhov ua tau zoo tshaj plaws (hauv chav kawm "A") tsis ntau tshaj 50%. Tab sis tsis yog lub hwj chim los yog qhov ua tau zoo ntawm lub amplifier yog qhov qhia txog qhov zoo ntawm lub suab tsim tawm. Nyob rau tib lub sij hawm, qhov zoo thiab linearity ntawm cov yam ntxwv ntawm tag nrho cov EREs nyob rau hauv lub Circuit Court yog ib qho tseem ceeb tshwj xeeb.
Raws li ib-kawg circuits tau txais qhov kev xav no, peb yuav saib lawv cov kev xaiv hauv qab no.
Single-ended single-transistor amplifier
Nws lub voj voog, ua nrog ib qho emitter thiab R-C kev sib txuas rau kev tawm tswv yim thiab tso tawm cov cim rau kev ua haujlwm hauv chav kawm "A", yog qhia hauv daim duab hauv qab no.
Nws qhia txog n-p-n transistor Q1. Nws cov khoom siv txuas nrog + Vcc zoo davhlau ya nyob twg ntawm qhov tam sim no-txheej resistor R3, thiab nws cov emitter txuas nrog -Vcc. Lub p-n-p transistor amplifier yuav muaj tib lub voj voog, tab sis cov khoom siv hluav taws xob yuav raug thim rov qab.
C1 yog ib qho kev txiav tawm uas cais cov AC input qhov chaw los ntawm DC voltage qhov chaw Vcc. Nyob rau tib lub sijhawm, C1 tsis tiv thaiv kev hla ntawm kev hloov pauv tam sim no los ntawm lub hauv paus-emitter hlws ris ntawm transistor Q1. Resistor R1 thiab R2 ua ke nrog kev ua haujlwmKev hloov pauv "E - B" tsim qhov voltage divider Vcc los xaiv qhov chaw ua haujlwm ntawm transistor Q1 hauv hom zoo li qub. Hom rau qhov Circuit Court no yog tus nqi ntawm R2=1 kOhm, thiab txoj haujlwm ntawm qhov chaw ua haujlwm yog Vcc / 2. R3 yog cov khoom siv hluav taws xob hluav taws xob hluav taws xob thiab siv los tsim cov hluav taws xob sib txawv ntawm cov zis hluav taws xob ntawm cov khoom siv.
Xav tias Vcc=20 V, R2=1 kOhm, thiab tam sim no nce h=150. Peb xaiv qhov hluav taws xob ntawm lub emitter Ve=9 V, thiab qhov hluav taws xob poob ntawm kev hloov "A - B" yog coj sib npaug rau Vbe=0.7 V. Tus nqi no sib haum mus rau qhov hu ua silicon transistor. Yog tias peb tab tom xav txog lub tshuab hluav taws xob raws li germanium transistors, ces qhov hluav taws xob poob thoob plaws qhov qhib kev sib tshuam "E - B" yuav yog Vbe=0.3 V.
Emitter tam sim no, kwv yees sib npaug rau cov khoom tam sim no
Ie=9 V / 1 kΩ=9 mA ≈ Ic.
Base current Ib=Ic/h=9mA/150=60uA.
Voltage poob hla resistor R1
V(R1)=Vcc - Vb=Vcc - (Vbe + Ve)=20V - 9.7V=10.3V
R1=V(R1)/Ib=10, 3 V/60 uA=172 kOhm.
C2 yog xav tau los tsim ib lub voj voog rau kev nkag mus ntawm cov khoom sib txawv ntawm cov emitter tam sim no (qhov tseeb yog cov khoom siv tam sim no). Yog tias nws tsis nyob ntawd, ces tus resistor R2 yuav txwv tsis pub muaj qhov sib txawv ntawm qhov sib txawv, kom lub tshuab hluav taws xob bipolar hauv nqe lus nug yuav muaj qhov nce qis tam sim no.
Nyob rau hauv peb cov kev xam, peb assumed tias Ic=Ib h, qhov twg Ib yog lub hauv paus tam sim no ntws mus rau hauv nws los ntawm lub emitter thiab tshwm sim thaum ib tug bias voltage yog siv rau lub hauv paus. Txawm li cas los xij, los ntawm lub hauv paus ib txwm (ob leeg nrog thiab tsis muaj offset)Kuj tseem muaj qhov xau tam sim no los ntawm cov khoom siv Icb0. Yog li ntawd, lub real collector tam sim no yog Ic=Ib h + Icb0 h, i.e. cov xau tam sim no hauv Circuit Court nrog OE yog amplified los ntawm 150 zaug. Yog hais tias peb tab tom txiav txim siab lub amplifier raws li germanium transistors, ces qhov xwm txheej no yuav tsum tau coj mus rau hauv tus account hauv kev suav. Qhov tseeb yog tias germanium transistors muaj qhov tseem ceeb Icb0 ntawm qhov kev txiav txim ntawm ob peb μA. Hauv silicon, nws yog peb qhov kev txiav txim siab me me (txog ob peb nA), yog li nws feem ntau tsis saib xyuas hauv kev suav.
Ib-kawg MIS transistor amplifier
Zoo li txhua qhov cuam tshuam ntawm transistor amplifier, Circuit Court hauv nqe lus nug muaj nws cov analogue ntawm bipolar transistor amplifiers. Yog li ntawd, xav txog ib tug analogue ntawm lub yav dhau los Circuit Court nrog ib tug ntau emitter. Nws yog tsim los nrog ib qho kev sib txuas thiab R-C kev sib txuas rau kev tawm tswv yim thiab tso tawm cov cim rau kev ua haujlwm hauv chav kawm "A" thiab tau pom hauv daim duab hauv qab no.
Ntawm no C1 yog tib lub decoupling capacitor, los ntawm txoj kev uas AC input qhov chaw yog cais los ntawm DC voltage qhov chaw Vdd. Raws li koj paub, txhua qhov kev cuam tshuam transistor amplifier yuav tsum muaj lub rooj vag muaj peev xwm ntawm nws cov MOS transistors hauv qab qhov muaj peev xwm ntawm lawv qhov chaw. Nyob rau hauv lub Circuit Court no, lub rooj vag yog grounded los ntawm R1, uas feem ntau yog siab kuj (100 kΩ mus rau 1 MΩ) thiaj li hais tias nws tsis shunt lub input teeb liab. Muaj kev xyaum tsis muaj tam sim no los ntawm R1, yog li lub rooj vag muaj peev xwm nyob rau hauv qhov tsis muaj lub tswv yim teeb liab sib npaug rau hauv av muaj peev xwm. Qhov peev xwm muaj peev xwm siab dua hauv av muaj peev xwm vim qhov hluav taws xob poob thoob plaws lub resistor R2. Yog liYog li, lub rooj vag muaj peev xwm qis dua qhov peev txheej, uas yog qhov tsim nyog rau kev ua haujlwm li qub ntawm Q1. Capacitor C2 thiab resistor R3 muaj tib lub hom phiaj zoo ib yam li hauv Circuit Court dhau los. Txij li qhov no yog ib qho kev sib koom ua ke, cov tswv yim thiab cov teeb liab tawm tawm ntawm theem los ntawm 180 °.
Transformer tso zis amplifier
Qhov thib peb ib-theem yooj yim transistor amplifier, muaj nyob rau hauv daim duab hauv qab no, kuj yog ua raws li cov emitter Circuit Court rau kev ua haujlwm hauv chav kawm "A", tab sis nws txuas nrog tus hais lus qis impedance los ntawm kev sib txuam. transformer.
Thawj winding ntawm transformer T1 yog lub collector Circuit Court load ntawm transistor Q1 thiab tsim ib tug tso zis teeb liab. T1 xa cov teeb liab tawm mus rau tus neeg hais lus thiab xyuas kom meej tias cov zis impedance ntawm lub transistor sib tw qis (ntawm qhov kev txiav txim ntawm ob peb ohms) tus neeg hais lus impedance.
Qhov hluav taws xob faib hluav taws xob ntawm cov khoom siv hluav taws xob Vcc, sib sau ua ke ntawm cov resistors R1 thiab R3, muab kev xaiv ntawm qhov chaw khiav hauj lwm ntawm lub transistor Q1 (muab qhov tsis zoo voltage rau nws lub hauv paus). Lub hom phiaj ntawm cov khoom seem ntawm lub amplifier yog tib yam li nyob rau hauv lub voj voog dhau los.
Push-rub audio amplifier
Lub ob-transistor thawb-rub qis-zaus amplifier faib cov tswv yim suab teeb liab rau hauv ob theem tawm ib nrab-yoj, txhua qhov uas yog amplified los ntawm nws tus kheej transistor theem. Tom qab qhov kev nthuav dav no tau ua tiav, ib nrab nthwv dej tau muab tso rau hauv ib qho kev sib haum xeeb ua tiav, uas tau xa mus rau cov neeg hais lus. Xws li ib tug transformation ntawm tsawg zausteeb liab (splitting thiab re-fusion), tau kawg, ua rau irreversible distortion nyob rau hauv nws, vim qhov txawv nyob rau hauv zaus thiab dynamic zog ntawm ob transistors ntawm lub Circuit Court. Qhov no distortion txo cov suab zoo ntawm cov zis ntawm lub amplifier.
Push-rub amplifiers ua haujlwm hauv chav kawm "A" tsis rov tsim cov suab nrov nrov txaus, vim tias qhov tam sim no txuas ntxiv mus tas li hauv lawv txhais tes. Qhov no ua rau asymmetry ntawm ib nrab nthwv dej ntawm lub teeb liab, theem distortions thiab, thaum kawg, mus rau qhov poob ntawm lub suab intelligibility. Thaum rhuab, ob lub zog transistors muab ob npaug rau lub teeb liab distortion nyob rau hauv qis thiab infra-low frequencies. Tab sis tseem, lub ntsiab kom zoo dua ntawm lub laub-rub Circuit Court yog nws qhov ua tau zoo thiab muaj zog tso zis ntau ntxiv.
Push-rub transistor fais fab amplifier Circuit Court yog qhia hauv daim duab.
Qhov no yog chav kawm "A" amplifier, tab sis chav kawm "AB" thiab txawm "B" kuj siv tau.
Transformerless Transistor Fais Fab Amplifier
Transformers, txawm tias qhov kev nce qib hauv lawv qhov kev ua haujlwm me me, tseem yog qhov loj tshaj plaws, hnyav thiab kim ERE. Yog li ntawd, ib txoj hauv kev tau pom los tshem tawm cov transformer los ntawm lub laub-rub Circuit Court los ntawm kev khiav nws ntawm ob lub zog sib txuas ntawm transistors ntawm ntau hom (n-p-n thiab p-n-p). Feem ntau niaj hnub fais fab amplifiers siv txoj cai no thiab tsim los ua haujlwm hauv chav kawm "B". Lub voj voog ntawm lub hwj chim amplifier yog qhia hauv daim duab hauv qab no.
Ob leeg ntawm nws cov transistors txuas nrog raws li cov khoom sib xws (emitter follower) circuit. Yog li ntawd, lub Circuit Court hloov lub input voltage rau cov zis yam tsis muaj amplification. Yog tias tsis muaj lub teeb liab tawm, ces ob lub transistors nyob ntawm ciam teb ntawm lub xeev, tab sis lawv raug tua.
Thaum lub teeb liab sib haum xeeb yog cov tswv yim, nws qhov zoo ib nrab-yoj qhib TR1, tab sis muab tso rau p-n-p transistor TR2 hauv tag nrho cov kev txiav tawm. Yog li, tsuas yog qhov zoo ib nrab-yoj ntawm lub amplified tam sim no ntws los ntawm lub load. Qhov tsis zoo ib nrab nthwv dej ntawm cov teeb liab tawm tswv yim qhib tsuas yog TR2 thiab tua TR1, kom qhov tsis zoo ib nrab-yoj ntawm amplified tam sim no nkag mus rau lub load. Raws li qhov tshwm sim, tag nrho lub zog amplified (vim tam sim no amplification) sinusoidal teeb liab raug xa mus rau lub load.
Ib leeg transistor amplifier
Yuav kom ua raws li cov saum toj no, peb yuav sib sau ua ke ib qho yooj yim transistor amplifier nrog peb tus kheej tes thiab xyuas seb nws ua haujlwm li cas.
Raws li kev thauj khoom ntawm lub tshuab hluav taws xob qis T ntawm hom BC107, peb tig lub mloog pob ntseg nrog qhov tsis kam ntawm 2-3 kOhm, peb siv qhov tsis zoo ntawm qhov hluav taws xob mus rau lub hauv paus los ntawm qhov muaj zog resistor Rntawm 1. MΩ, peb qhib lub decoupling electrolytic capacitor C nrog lub peev xwm ntawm 10 μF mus rau 100 μF nyob rau hauv lub hauv paus Circuit T. Peb yuav siv fais fab Circuit Court los ntawm lub roj teeb ntawm 4.5 V / 0.3 A.
Yog resistor Rtsis txuas, ces tsis muaj lub hauv paus tam sim no Ib lossis cov khoom siv tam sim no Ic. Yog hais tias tus resistor txuas, ces qhov voltage ntawm lub hauv paus nce mus rau 0.7 V thiab ib tug tam sim no Ib \u003d 4 μA ntws los ntawm nws. CoefficientTam sim no qhov nce ntawm transistor yog 250, uas muab Ic=250Ib=1 mA.
Tau sib sau ua ke ib qho yooj yim transistor amplifier nrog peb tus kheej tes, tam sim no peb tuaj yeem sim nws. Txuas lub mloog pob ntseg thiab tso koj tus ntiv tes rau ntawm taw tes 1 ntawm daim duab. Koj yuav hnov suab nrov. Koj lub cev pom cov hluav taws xob ntawm lub ntsiab ntawm qhov zaus ntawm 50 Hz. Lub suab nrov uas koj hnov los ntawm lub mloog pob ntseg yog qhov hluav taws xob no, tsuas yog amplified los ntawm transistor. Cia peb piav qhia txog cov txheej txheem no kom ntxaws ntxiv. Ib qho AC voltage ntawm 50 Hz yog txuas nrog lub hauv paus ntawm transistor los ntawm capacitor C. Qhov voltage ntawm lub hauv paus yog tam sim no sib npaug rau qhov sib npaug ntawm DC bias voltage (kwv yees li 0.7 V) los ntawm resistor Rthiab AC ntiv tes voltage. Raws li qhov tshwm sim, cov khoom siv tam sim no tau txais cov khoom sib txuas nrog zaus ntawm 50 Hz. Qhov kev hloov pauv tam sim no yog siv los txav cov membrane ntawm cov neeg hais lus rov qab los ntawm tib zaus, uas txhais tau tias peb tuaj yeem hnov ib lub suab 50Hz ntawm qhov tso zis.
Hnub 50 Hz suab nrov tsis yog qhov nthuav heev, yog li koj tuaj yeem txuas cov khoom siv tsawg zaus (CD player lossis microphone) rau cov ntsiab lus 1 thiab 2 thiab hnov cov lus hais lossis suab paj nruag.
