Nkauj Tsim. Txoj kev ntseeg - part 2

Kuv tau sau txog qhov tseeb tias kev txawj ntse hauv cov txheej txheem ntawm kev tsim suab paj nruag yog cov kauj ruam kawg ntawm txoj kev los ntawm lub tswv yim ntawm cov suab paj nruag mus rau nws qhov kev xa mus rau tus neeg tau txais hauv qhov teeb meem dhau los. Peb kuj tau ua tib zoo saib cov suab kaw suab, tab sis kuv tseem tsis tau tham txog yuav ua li cas lub suab no, hloov mus rau AC voltage converters, hloov mus rau binary daim ntawv.

1. Txhua lub suab nyuaj, txawm tias muaj kev nyuaj siab heev, yeej muaj ntau lub suab sinusoidal yooj yim.

Kuv xaus rau tsab xov xwm dhau los nrog cov lus nug, yuav ua li cas thiaj li muaj peev xwm nyob rau hauv xws li ib tug undulating yoj (1) tag nrho cov suab paj nruag cov ntsiab lus yog encoded, txawm hais tias peb tab tom tham txog ntau yam twj paj nruag ua si polyphonic qhov chaw? Ntawm no yog cov lus teb: qhov no yog vim lub fact tias tej complex suab, txawm heev complex, yog tiag tiag nws muaj ntau yam yooj yim sinusoidal suab.

Lub sinusoidal xwm ntawm cov waveforms yooj yim no sib txawv nrog lub sij hawm thiab amplitude, cov waveforms overlapping, ntxiv, rho tawm, modulating ib leeg thiab yog li ua ntej tsim ib tug neeg lub suab seev thiab ces ua kom tiav mixes thiab kaw.

Qhov peb pom hauv daim duab 2 yog qee cov atoms, cov molecules uas ua rau peb lub suab teeb meem, tab sis nyob rau hauv cov ntaub ntawv ntawm ib tug analog teeb liab tsis muaj xws li atoms - muaj ib tug txawm kab, tsis muaj dots cim tom qab nyeem ntawv (qhov txawv yuav pom nyob rau hauv. daim duab nyob rau hauv raws li cov kauj ruam, uas yog graphically approximated kom tau cov coj mus muag nyhuv).

Txawm li cas los xij, txij li thaum playback ntawm cov suab paj nruag kaw los ntawm analog lossis cov peev txheej digital yuav tsum tau ua los ntawm kev siv lub tshuab electromagnetic transducer xws li lub suab nrov lossis lub mloog pob ntseg transducer, feem ntau ntawm qhov sib txawv ntawm cov ntshiab analog suab thiab digitally ua suab blurs. Nyob rau theem kawg, i.e. thaum mloog, cov suab paj nruag ncav cuag peb ib yam li cov kev vibrations ntawm cov huab cua uas tshwm sim los ntawm kev txav ntawm lub diaphragm nyob rau hauv lub transducer.

2. Molecules uas ua rau peb lub suab teeb meem

analog lej

Puas muaj qhov sib txawv ntawm lub suab zoo nkauj (piv txwv li kaw cov analog ntawm lub kaw lus analog, sib xyaw ntawm lub console analog, compressed rau ntawm analog disc, rov qab rau hauv analog player thiab amplified analog amplifier) ​​​​thiab cov suab digital - hloov los ntawm analog rau digital, ua tiav thiab sib xyaw digitally thiab tom qab ntawd ua tiav rov qab rau hauv daim ntawv analog, puas yog nyob rau hauv pem hauv ntej ntawm lub amp lossis xyaum hauv tus neeg hais lus nws tus kheej?

Feem ntau ntawm cov xwm txheej, tsis yog, txawm hais tias yog peb kaw cov khoom siv suab paj nruag tib yam hauv ob txoj hauv kev thiab tom qab ntawd ua si rov qab, qhov sib txawv yeej yuav hnov. Txawm li cas los xij, qhov no yuav yog vim qhov zoo ntawm cov cuab yeej siv hauv cov txheej txheem no, lawv cov yam ntxwv, cov khoom, thiab feem ntau cov kev txwv, dua li qhov tseeb ntawm kev siv analog lossis digital technology.

Tib lub sijhawm, peb xav tias nqa lub suab mus rau ib daim ntawv digital, i.e. kom meej meej atomized, tsis cuam tshuam rau lub kaw lus thiab ua cov txheej txheem nws tus kheej, tshwj xeeb tshaj yog vim cov qauv no tshwm sim ntawm ib zaus uas - yam tsawg kawg nkaus theoretically - yog deb tshaj qhov siab tshaj ntawm cov zaus peb hnov, thiab yog li no tshwj xeeb graininess ntawm lub suab hloov dua siab tshiab rau daim ntawv digital, yog qhov tsis pom rau peb. Txawm li cas los xij, los ntawm qhov pom ntawm kev paub txog cov khoom siv suab, nws tseem ceeb heev, thiab peb yuav tham txog nws tom qab.

Tam sim no cia peb xam seb yuav ua li cas lub teeb liab analog hloov mus rau digital daim ntawv, uas yog xoom-ib, i.e. ib qhov twg qhov voltage tsuas muaj ob theem: cov digital ib theem, uas txhais tau hais tias voltage, thiab tus lej xoom theem, i.e. qhov nro no yog xyaum tsis muaj. Txhua yam hauv ntiaj teb digital yog ib qho lossis xoom, tsis muaj qhov tseem ceeb nruab nrab. Tau kawg, tseem muaj qhov hu ua fuzzy logic, qhov twg tseem muaj cov xeev nruab nrab ntawm "rau" lossis "tawm" xeev, tab sis nws tsis muaj feem xyuam rau cov tshuab suab digital.

3. Kev vibrations ntawm huab cua hais tawm los ntawm lub suab nrov teeb tsa hauv kev txav ib lub teeb heev ntawm daim nyias nyias.

Transformations Part XNUMX

Txhua lub teeb liab acoustic, txawm hais tias nws yog suab, acoustic guitar lossis nruas, raug xa mus rau lub computer hauv daim ntawv digital, nws yuav tsum xub hloov dua siab tshiab rau hauv ib qho kev hloov hluav taws xob teeb liab. Qhov no feem ntau yog ua nrog microphones nyob rau hauv uas vibrations ntawm huab cua hais los ntawm lub suab qhov chaw tsav lub teeb heev diaphragm qauv (3). Qhov no tej zaum yuav yog lub diaphragm nyob rau hauv lub condenser capsule, ib tug hlau ntawv ci band nyob rau hauv ib tug ribbon microphone, los yog ib tug diaphragm nrog ib tug coil txuas rau nws nyob rau hauv ib tug dynamic microphone.

Hauv txhua qhov xwm txheej no ib qho tsis muaj zog heev, oscillating hluav taws xob teeb liab tshwm ntawm qhov tso zis ntawm lub microphoneuas ntau dua los yog tsawg dua khaws cia cov proportions ntawm zaus thiab theem sib xws rau tib yam tsis muaj oscillating cua hais. Yog li, qhov no yog ib hom hluav taws xob analogue ntawm nws, uas tuaj yeem ua tiav hauv cov khoom siv uas ua cov teeb liab hloov hluav taws xob.

Thaum xub thawj microphone teeb liab yuav tsum tau amplifiedvim nws tsis muaj zog heev los siv rau txhua txoj kev. Ib tug raug microphone tso zis voltage yog nyob rau hauv qhov kev txiav txim ntawm txhiabths ntawm ib volt, qhia nyob rau hauv millivolts, thiab feem ntau nyob rau hauv microvolts los yog millionths ntawm ib volt. Rau kev sib piv, cia peb ntxiv tias lub roj teeb hom ntiv tes ua ib qho hluav taws xob ntawm 1,5 V, thiab qhov no yog qhov hluav taws xob tas li uas tsis raug hloov kho, uas txhais tau hais tias nws tsis xa cov ntaub ntawv suab.

Txawm li cas los xij, DC voltage yog xav tau nyob rau hauv txhua lub tshuab hluav taws xob los ua lub zog, uas yuav hloov kho lub teeb liab AC. Lub tshuab nqus tsev thiab ua haujlwm tau zoo dua lub zog no, qhov tsawg dua nws raug rau cov khoom siv tam sim no thiab kev cuam tshuam, lub tshuab nqus tsev AC teeb liab ua tiav los ntawm cov khoom siv hluav taws xob yuav yog. Yog li ntawd, lub hwj chim mov, uas yog lub hwj chim mov, yog li ntawd ib qho tseem ceeb nyob rau hauv tej analog suab system.

4. Microphone amplifier, tseem hu ua preamplifier lossis preamplifier

Microphone amplifiers, tseem hu ua preamplifiers los yog preamplifiers, yog tsim los rau amplify lub teeb liab ntawm microphones (4). Lawv txoj hauj lwm yog ua kom lub teeb liab, feem ntau txawm tias los ntawm ob peb kaum ntawm decibels, uas txhais tau tias kom nce lawv qib los ntawm ntau pua lossis ntau dua. Yog li, ntawm qhov tso zis ntawm lub preamplifier, peb tau txais ib qho kev hloov hluav taws xob uas yog ncaj qha proportional rau lub input voltage, tab sis tshaj nws los ntawm ntau pua zaus, i.e. nyob rau hauv ib theem ntawm cov feem mus rau units ntawm volts. Qhov teeb liab theem no raug txiav txim kab theem thiab qhov no yog cov txheej txheem kev khiav hauj lwm hauv cov khoom siv suab.

Kev hloov pauv qhov thib ob

Ib qho analog teeb liab ntawm qib no tuaj yeem dhau mus txheej txheem digitization. Qhov no yog ua tiav siv cov cuab yeej hu ua analog-to-digital converters lossis transducers (5). Cov txheej txheem hloov dua siab tshiab hauv hom PCM classic, i.e. Pulse Width Modulation, tam sim no yog hom kev ua haujlwm nrov tshaj plaws, tau txhais los ntawm ob qhov tsis muaj: sampling tus nqi thiab qhov tob me ntsis. Raws li koj xav tau tiag tiag, qhov siab dua cov ntsuas no, qhov zoo dua qhov hloov dua siab tshiab thiab qhov tseeb dua lub teeb liab yuav raug pub rau lub computer hauv daim ntawv digital.

5. Converter lossis analog-rau-digital converter.

Txoj cai dav dav rau hom kev hloov pauv no kev kuaj, uas yog, coj cov qauv ntawm cov khoom siv analog thiab tsim cov sawv cev digital ntawm nws. Ntawm no, tus nqi tam sim ntawm qhov hluav taws xob nyob rau hauv lub teeb liab analog yog txhais thiab nws qib yog sawv cev digitally hauv binary system (6).

Ntawm no, txawm li cas los xij, nws yog ib qho tsim nyog yuav tsum nco ntsoov luv luv ntawm cov hauv paus ntawm kev ua lej, raws li qhov muaj txiaj ntsig tus lej tuaj yeem sawv cev hauv txhua tus lej system. Thoob plaws hauv keeb kwm ntawm noob neej, ntau lub tshuab xov tooj tau ua thiab tseem siv. Piv txwv li, cov ntsiab lus xws li lub kaum os (12 daim) lossis ib lub nyiaj hli (12 lub kaum, 144 daim) yog raws li cov txheej txheem duodecimal.

6. Voltage qhov tseem ceeb nyob rau hauv ib qho analog teeb liab thiab sawv cev ntawm nws cov theem nyob rau hauv digital daim ntawv nyob rau hauv ib tug binary system

Rau lub sijhawm, peb siv cov tshuab sib xyaw - sexagesimal rau vib nas this, feeb thiab teev, duodecimal derivative rau hnub thiab hnub, xya system rau hnub ntawm lub lim tiam, quad system (kuj muaj feem xyuam rau duodecimal thiab sexagesimal system) rau lub lis piam hauv ib hlis, duodecimal system los qhia lub hli ntawm lub xyoo, thiab tom qab ntawd peb txav mus rau qhov kev ua lej, qhov twg xyoo caum, ntau pua xyoo thiab txhiab xyoo tshwm. Kuv xav tias qhov piv txwv ntawm kev siv cov tshuab sib txawv los qhia txog lub sijhawm dhau los tau zoo heev qhia txog qhov xwm txheej ntawm cov lej thiab yuav tso cai rau koj kom muaj txiaj ntsig zoo dua rau cov teeb meem ntsig txog kev hloov dua siab tshiab.

Nyob rau hauv cov ntaub ntawv ntawm analog rau digital hloov dua siab tshiab, peb yuav yog cov feem ntau hloov decimal qhov tseem ceeb rau binary qhov tseem ceeb. Decimal vim tias qhov ntsuas rau txhua tus qauv feem ntau qhia hauv microvolts, millivolts thiab volts. Ces tus nqi no yuav qhia nyob rau hauv binary system, i.e. siv ob lub khoom ua haujlwm hauv nws - 0 thiab 1, uas qhia txog ob lub xeev: tsis muaj qhov hluav taws xob lossis nws muaj, tawm lossis qhib, tam sim no lossis tsis, thiab lwm yam. Yog li, peb tsis txhob cuam tshuam, thiab txhua yam ua tau yooj yim dua hauv kev siv los ntawm daim ntawv thov. qhov kev hloov pauv ntawm algorithms uas peb tab tom ua, piv txwv li, cuam tshuam nrog cov khoom sib txuas lossis lwm cov txheej txheem digital.

Koj yog xoom; los yog ib

Nrog ob tus lej no, xoom thiab ib qho, koj tuaj yeem nthuav tawm txhua tus nqitsis hais nws qhov loj me. Ua piv txwv, xav txog tus lej 10. Tus yuam sij rau kev nkag siab txog zauv-rau-binary hloov dua siab tshiab yog tias tus lej 1 hauv binary, ib yam li cov lej, nyob ntawm nws txoj haujlwm hauv cov lej xov tooj.

Yog tias 1 nyob rau qhov kawg ntawm txoj hlua binary, ces 1, yog tias nyob rau hauv qhov thib ob los ntawm qhov kawg - ces 2, nyob rau hauv peb txoj hauj lwm - 4, thiab nyob rau hauv lub plaub txoj hauj lwm - 8 - tag nrho cov zauv. Hauv cov lej lej, tib 1 qhov kawg yog 10, qhov kawg ntawm 100, thib peb 1000, plaub XNUMX yog piv txwv kom nkag siab qhov piv txwv.

Yog li, yog tias peb xav sawv cev rau 10 hauv binary daim ntawv, peb yuav tsum sawv cev rau 1 thiab 1, yog li kuv hais, nws yuav yog 1010 hauv plaub qhov chaw thiab XNUMX hauv qhov thib ob, uas yog XNUMX.

Yog tias peb xav tau los hloov qhov voltages ntawm 1 mus rau 10 volts yam tsis muaj qhov tseem ceeb, piv txwv li. siv cov lej xwb, lub converter uas tuaj yeem sawv cev rau 4-ntsis sequences hauv binary yog txaus. 4-ntsis vim qhov kev hloov pauv binary no yuav xav tau txog plaub tus lej. Hauv kev xyaum nws yuav zoo li no:

0 0000

1 0001

2 0010

3 0011

4 0100

5 0101

6 0110

7 0111

8 1000

9 1001

10 1010

Cov uas ua xoom rau cov lej 1 txog 7 tsuas yog khij txoj hlua rau tag nrho plaub cov khoom kom txhua tus lej binary muaj tib lub syntax thiab siv tib qhov chaw. Nyob rau hauv daim ntawv graphical, xws li ib tug txhais lus ntawm integers los ntawm lub decimal system rau binary yog qhia nyob rau hauv daim duab 7.

7. Hloov Integers hauv Decimal System rau Binary System

Ob qho tib si sab sauv thiab sab qis sawv cev rau cov txiaj ntsig zoo ib yam, tshwj tsis yog qhov qub nkag siab, piv txwv li, rau cov khoom siv analog, xws li cov kab hluav taws xob theem ntsuas, thiab qhov thib ob rau cov khoom siv digital, suav nrog cov khoos phis tawj uas ua cov ntaub ntawv ntawm cov lus zoo li no. Qhov no hauv qab waveform zoo li qhov sib txawv-square yoj, i.e. sib txawv ntawm qhov siab tshaj qhov tseem ceeb rau qhov tsawg kawg nkaus qhov tseem ceeb nyob rau lub sijhawm. Cov ntsiab lus sib txawv no encodes tus nqi binary ntawm lub teeb liab kom hloov, yog li lub npe "mem tes code modulation" - PCM.

Tam sim no rov qab mus rau converting ib tug tiag tiag analog teeb liab. Peb twb paub lawm tias nws tuaj yeem piav qhia los ntawm ib kab uas qhia txog kev hloov pauv hloov pauv tau yooj yim, thiab tsis muaj ib qho piv txwv dhia ntawm cov qib no. Txawm li cas los xij, rau cov kev xav tau ntawm analog rau digital hloov dua siab tshiab, peb yuav tsum qhia cov txheej txheem zoo li no kom muaj peev xwm ntsuas cov theem ntawm cov teeb liab analog ntawm lub sijhawm thiab sawv cev rau txhua tus qauv ntsuas hauv daim ntawv digital.

Nws tau xav tias qhov zaus ntawm qhov kev ntsuas no yuav tsum yog tsawg kawg ob zaug ntawm qhov zaus siab tshaj plaws uas tus neeg tuaj yeem hnov, thiab txij li nws yog kwv yees li 20 kHz, yog li ntawd, feem ntau. 44,1kHz tseem yog tus qauv nrov. Kev suav ntawm tus lej piv txwv yog txuam nrog kev ua lej nyuaj, uas, nyob rau theem no ntawm peb txoj kev paub txog kev hloov pauv, tsis muaj txiaj ntsig.

Ntau puas zoo dua?

Txhua yam uas kuv tau hais los saum toj no yuav qhia tau tias qhov siab dua qhov piv txwv, piv txwv li. ntsuas cov theem ntawm cov teeb liab analog ntawm lub sijhawm tsis tu ncua, qhov zoo dua ntawm kev hloov dua siab tshiab, vim tias nws yog - tsawg kawg hauv kev nkag siab zoo - ntau qhov tseeb. Puas yog tiag? Peb yuav paub txog qhov no hauv ib hlis.