Ukudala Umculo. Ukuphumelela - Ingxenye 2

Ngabhala mayelana neqiniso lokuthi ukwenza kahle enqubweni yokukhiqiza umculo kuyisinyathelo sokugcina endleleni kusukela emcabangweni womculo kuya ekulethweni kwawo kumamukeli kumagazini odlule. Siphinde sabhekisisa kahle umsindo orekhodiwe ngedijithali, kodwa angikakaxoxi ukuthi lo msindo, oguqulelwe ku-AC voltage converters, uguqulwa kanjani ube ifomu kanambambili.

1. Wonke umsindo oyinkimbinkimbi, ngisho nezinga eliphakeme kakhulu lokuyinkimbinkimbi, empeleni liqukethe imisindo eminingi elula ye-sinusoidal.

Ngiqede isihloko esandulele ngombuzo othi, kungenzeka kanjani ukuthi kugagasi elingaka (1) konke okuqukethwe komculo kufakwe ikhodi, noma ngabe sikhuluma ngezinsimbi eziningi ezidlala izingxenye ze-polyphonic? Nansi impendulo: lokhu kungenxa yokuthi noma yimuphi umsindo oyinkimbinkimbi, ngisho noyinkimbinkimbi kakhulu, ngempela iqukethe imisindo eminingi elula ye-sinusoidal.

Imvelo ye-sinusoidal yalawa magagasi alula ayahluka kokubili kwesikhathi kanye nobukhulu, lawa magagasi ayagqagqana, angeze, akhiphe, ashintshane futhi ngaleyo ndlela aqale adale imisindo yensimbi ngayinye bese eqedela imiksi nokuqoshwa.

Esikubona emfanekisweni wesi-2 ama-athomu athile, ama-molecule akha udaba lwethu lomsindo, kodwa esimweni sesignali ye-analog awekho ama-athomu anjalo - kukhona umugqa owodwa, ngaphandle kwamachashazi omaka ukufundwa okulandelayo (umehluko ungabonakala isibalo njengezinyathelo, ezicishe zifanekiswe ukuze kutholwe umphumela wokubuka ohambisanayo).

Kodwa-ke, njengoba ukudlalwa kabusha komculo orekhodiwe ovela emithonjeni ye-analog noma yedijithali kufanele kwenziwe kusetshenziswa i-transducer kagesi eyimishini njengesipikha noma i-transducer ye-headphone, umehluko omkhulu phakathi komsindo we-analog omsulwa kanye nokufiphala komsindo ocutshungulwe ngokwedijithali. Esigabeni sokugcina, i.e. lapho ulalela, umculo usifinyelela ngendlela efanayo nokudlidliza kwezinhlayiya zomoya ezibangelwa ukunyakaza kwe-diaphragm ku-transducer.

2. Amangqamuzana akha indaba yethu ezwakalayo

idijithi ye-analog

Ingabe ukhona umehluko ozwakalayo phakathi komsindo we-analog omsulwa (okungukuthi, i-analog erekhodiwe kusiqophamazwi se-analog, exutshwe kukhonsoli ye-analog, icindezelwe kudiski ye-analog, edlalwa futhi kusidlali se-analog ne-amplifier ye-analog ekhulisiwe) nomsindo wedijithali - oguqulelwe kusuka i-analog iye kudijithali, icutshungulwe futhi ixutshwe ngokwedijithali bese icutshungulwa ibuyiselwe kufomu le-analog, ingabe lokho kuphambi kwe-amp noma ngokwesipikha ngokwaso?

Ezimweni eziningi, hhayi, nakuba uma siqopha umculo ofanayo ngazo zombili izindlela bese siwudlala, umehluko ubuzozwakala. Kodwa-ke, lokhu kuzoba ngenxa yemvelo yamathuluzi asetshenziswa kulezi zinqubo, izici zawo, izakhiwo, kanye nemikhawulo evamise ukudlula iqiniso lokusebenzisa ubuchwepheshe be-analog noma bedijithali.

Ngesikhathi esifanayo, sicabanga ukuthi ukuletha umsindo kwifomu ledijithali, i.e. ukwenza ngokusobala i-athomu, ayithinti kakhulu inqubo yokuqopha nokucubungula ngokwayo, ikakhulukazi njengoba lawa masampuli enzeka ngemvamisa - okungenani ngokwethiyori - engaphezu kwemikhawulo ephezulu yamafrikhwensi esiwazwayo, futhi ngenxa yalokho lobu bunzima bomsindo obuguquliwe. kusimo sedijithali, asibonakali kithi. Nokho, ngokombono wokwazi kahle ukwaziswa okuzwakalayo, kubaluleke kakhulu, futhi sizoxoxa ngakho kamuva.

Manje ake sithole ukuthi isignali ye-analog iguqulwa kanjani ibe ifomu ledijithali, okungukuthi zero-one, i.e. eyodwa lapho i-voltage ingaba namazinga amabili kuphela: ileveli yedijithali eyodwa, okusho ukuthi i-voltage, nezinga le-digital zero, i.e. lokhu kushuba akukho nhlobo. Yonke into emhlabeni wedijithali eyodwa noma uziro, awekho amanani amaphakathi. Kunjalo, kukhona nalokho okubizwa nge-logic engaqondakali, lapho kusenezifunda ezimaphakathi phakathi kwezifunda zokuthi "vuliwe" noma "ukuvala", kodwa ayisebenzi ezinhlelweni zomsindo wedijithali.

3. Ukudlidliza kwezinhlayiya zomoya okubangelwa umthombo womsindo kumiswa ukunyakaza okukhanyayo kolwelwesi.

Izinguquko Ingxenye yokuqala

Noma iyiphi isignali ye-acoustic, kungakhathaliseki ukuthi amazwi, isiginci esizwakalayo noma izigubhu, ithunyelwa kukhompyutha ngendlela yedijithali, kufanele kuqala iguqulwe ibe isignali kagesi eshintshanayo. Lokhu ngokuvamile kwenziwa ngemibhobho lapho ukudlidliza kwezinhlayiya zomoya okubangelwa umthombo womsindo kushayela ukwakheka kwe-diaphragm elula kakhulu (3). Lokhu kungase kube i-diaphragm efakwe ku-condenser capsule, ibhande le-foil yensimbi kumbhobho weribhoni, noma i-diaphragm enekhoyili enamathiselwe kuyo kumakrofoni oguqukayo.

Kuzo zonke lezi zimo isignali kagesi ebuthakathaka kakhulu, enyakazayo ibonakala ekuphumeni kombhobhookuthi ngokwezinga elikhulu noma elincane ligcine izilinganiso zokuvama kanye nezinga elihambisana nemingcele efanayo yezinhlayiya zomoya ezinyakazayo. Ngakho-ke, lolu uhlobo lwe-analogue kagesi yalo, engacutshungulwa ngokuqhubekayo kumadivayisi acubungula isignali kagesi eshintshanayo.

Ekuqaleni isignali yemakrofoni kufanele ikhuliswengoba ibuthakathaka kakhulu ukuthi ingasetshenziswa nganoma iyiphi indlela. I-voltage evamile yokukhipha imakrofoni ilandelana ngezinkulungwane ze-volt, evezwa ngama-millivolts, futhi ngokuvamile ngama-microvolts noma ama-millionths we-volt. Ukuze siqhathanise, ake sengeze ukuthi ibhethri elivamile lohlobo lweminwe likhiqiza i-voltage engu-1,5 V, futhi lena i-voltage engashintshi, okusho ukuthi ayidlulisi noma yiluphi ulwazi lomsindo.

Kodwa-ke, amandla kagesi e-DC ayadingeka kunoma yiluphi uhlelo lwe-elekthronikhi ukuze abe umthombo wamandla, azobe eseshintsha isignali ye-AC. Ihlanzekile futhi isebenza kahle kakhulu la mandla, kancane kancane ingaphansi kwemithwalo yamanje kanye nokuphazamiseka, ukuhlanza isignali ye-AC ecutshungulwa yizingxenye ze-elekthronikhi kuyoba. Yingakho ukunikezwa kwamandla, okungukuthi ukunikezwa kwamandla, kubaluleke kakhulu kunoma iyiphi isistimu yomsindo we-analog.

4. Isikhulisi semakrofoni, esaziwa nangokuthi i-preamplifier noma i-preamplifier

Izikhulisa-zwi zombhobho, ezaziwa nangokuthi ama-preamplifiers noma ama-preamplifiers, aklanyelwe ukukhulisa isignali evela kumakrofoni (4). Umsebenzi wabo uwukukhulisa umsindo, ngokuvamile ngisho nangamashumi amaningana ama-decibel, okusho ukwandisa izinga lawo ngamakhulu noma ngaphezulu. Ngakho, ekuphumeni kwe-preamplifier, sithola i-voltage eshintshanayo ngokulingana ngokuqondile ne-voltage yokufaka, kodwa idlule izikhathi ezingamakhulu, i.e. ezingeni ukusuka kumafrakshini ukuya kumayunithi ama-volts. Leli zinga lesiginali liyanqunywa izinga lomugqa futhi leli izinga elijwayelekile lokusebenza kumadivayisi alalelwayo.

Uguquko ingxenye yesibili

Isignali ye-analogi yaleli zinga isivele idlulisiwe inqubo yokwenza idijithali. Lokhu kwenziwa kusetshenziswa amathuluzi abizwa ngokuthi ama-analog-to-digital converters noma ama-transducers (5). Inqubo yokuguqulwa kumodi ye-PCM yakudala, i.e. I-Pulse Width Modulation, okwamanje imodi yokucubungula ethandwa kakhulu, ichazwa ngamapharamitha amabili: isilinganiso samasampula nokujula kancane. Njengoba usola ngendlela efanele, uma lezi zinhlaka ziphakeme, ukuguqulwa kuzoba ngcono futhi kunembe kakhulu isignali izonikezwa ikhompuyutha ngefomu ledijithali.

5. Isiguquli noma isiguquli se-analog-to-digital.

Umthetho ojwayelekile walolu hlobo lokuguqulwa amasampula, okungukuthi, ukuthatha amasampula wento ye-analog nokudala ukumelwa kwayo okudijithali. Lapha, inani elisheshayo le-voltage kusiginali ye-analog liyatolikwa futhi izinga layo limelelwa ngokwedijithali ohlelweni kanambambili (6).

Lapha, nokho, kuyadingeka ukukhumbula kafushane izisekelo zezibalo, ngokusho ukuthi noma yiliphi inani lezinombolo lingamelwa noma yiluphi uhlelo lwezinombolo. Kuwo wonke umlando wesintu, izimiso zezinombolo ezihlukahlukene ziye zasetshenziswa futhi zisasetshenziswa. Isibonelo, imiqondo efana neshumi nambili (izingcezu eziyi-12) noma isenti (ishumi nambili, izingcezu eziyi-12) zisekelwe ohlelweni lwe-duodecimal.

6. Amanani kagesi kusignali ye-analog nokumelwa kwezinga layo ngendlela yedijithali ohlelweni olu kanambambili

Isikhathi, sisebenzisa amasistimu axubile - i-sexagesimal imizuzwana, imizuzu namahora, i-duodecimal derivative yezinsuku nezinsuku, uhlelo lwesikhombisa lwezinsuku zeviki, uhlelo lwe-quad (futhi luhlobene ne-duodecimal kanye ne-sexagesimal system) amaviki enyanga, uhlelo lwe-duodecimal. ukukhombisa izinyanga zonyaka, bese sidlulela ohlelweni lwedesimali, lapho kuvela khona amashumi eminyaka, amakhulu eminyaka kanye nezinkulungwane zeminyaka. Ngicabanga ukuthi isibonelo sokusebenzisa amasistimu ahlukene ukuveza ukuhamba kwesikhathi sibonisa kahle imvelo yezinhlelo zezinombolo futhi sizokuvumela ukuthi uzulazule ngempumelelo ezindabeni ezihlobene nokuguqulwa.

Endabeni yokuguqulwa kwe-analog kuya kwedijithali, sizoba sivame kakhulu guqula amanani edesimali abe amanani kanambambili. Idesimali ngoba ukulinganisa kwesampula ngayinye kuvame ukuvezwa ngama-microvolts, ama-millivolts nama-volts. Khona-ke leli nani lizovezwa ohlelweni kanambambili, okungukuthi. kusetshenziswa izingcezu ezimbili ezisebenza kuyo - u-0 no-1, okubonisa izifunda ezimbili: akukho voltage noma ubukhona bayo, icishiwe noma ivuliwe, yamanje noma cha, njll. Ngakho, sigwema ukuhlanekezela, futhi zonke izenzo ziba lula kakhulu ekusebenziseni ngokusebenzisa lokho okubizwa ngokuthi ushintsho lwama-algorithms esisebenzisana nawo, isibonelo, ngokuhlobene nezixhumi noma amanye amaphrosesa edijithali.

Unguziro; noma eyodwa

Ngalawa madijithi amabili, oziro kanye nowodwa, ungakwazi ukuveza wonke amanani ezinombolokungakhathaliseki ubukhulu bayo. Njengesibonelo, cabangela inombolo engu-10. Isihluthulelo sokuqonda ukuguqulwa kwedesimali kuya kanambambili ukuthi inombolo engu-1 kokubini, njengakudesimali, incike endaweni yayo ochungechungeni lwenombolo.

Uma u-1 esekupheleni kwentambo kanambambili, khona-ke 1, uma okwesibili kusukela ekugcineni - bese kuba 2, endaweni yesithathu - 4, futhi endaweni yesine - 8 - konke ngedesimali. Kuhlelo lwedesimali, i-1 efanayo ekugcineni i-10, i-penultimate 100, eyesithathu i-1000, i-XNUMX yesine iyisibonelo sokuqonda isifaniso.

Ngakho-ke, uma sifuna ukumela u-10 ngendlela kanambambili, sizodinga ukumela u-1 no-1, ngakho-ke njengoba ngishilo, kuzoba ngu-1010 endaweni yesine no-XNUMX ngesekhondi, okungu-XNUMX.

Uma besidinga ukuguqula ama-voltage kusuka ku-1 kuya ku-10 volts ngaphandle kwamanani ama-fractional, i.e. kusetshenziswa izinombolo eziphelele kuphela, isiguquli esingamela ukulandelana kwamabhithi angu-4 kukanambambili kwanele. 4-bit ngoba lokhu kuguqulwa kwenombolo kanambambili kuzodinga kufika kumadijithi amane. Ekusebenzeni kuzobukeka kanje:

0 0000

1 0001

2 0010

3 0011

4 0100

5 0101

6 0110

7 0111

8 1000

9 1001

10 1010

Labo oziro abaholayo bezinombolo 1 kuya ku-7 bamane baphequlule iyunithi yezinhlamvu emabhithi amane agcwele ukuze inombolo kanambambili ngayinye ibe ne-syntax efanayo futhi ithathe indawo efanayo. Ngefomethi yesithombe, ukuhunyushwa okunjalo kwamanani aphelele ukusuka kusistimu yedesimali kuya kanambambili kuboniswa kuMfanekiso 7.

7. Guqula izinombolo kusistimu yedesimali zibe isistimu kanambambili

Kokubili amagagasi aphezulu naphansi amele amanani afanayo, ngaphandle kokuthi eyokuqala iyaqondakala, isibonelo, kumadivayisi e-analog, njengamamitha weleveli ye-voltage yomugqa, kanye nelesibili lemishini yedijithali, okuhlanganisa namakhompyutha acubungula idatha yalolo limi. Lesi sakhiwo samagagasi esingezansi sibukeka njengegagasi lesikwele elishintshashintshayo, i.e. isilinganiso esihlukile samanani aphezulu kuya kumanani amancane ngokuhamba kwesikhathi. Lokhu okuqukethwe okuguquguqukayo kufaka phakathi inani kanambambili lesiginali ezoguqulwa, yingakho igama elithi "pulse code modulation" - PCM.

Manje buyela ekuguquleni isignali ye-analog yangempela. Sesiyazi kakade ukuthi ingachazwa ngomugqa obonisa amaleveli ashintsha ngokushelela, futhi ayikho into efana nokumelela okugxumayo kwalawa maleveli. Nokho, ngezidingo zokuguqulwa kwe-analogi kuye kwedijithali, kufanele sethule inqubo enjalo ukuze sikwazi ukukala izinga lesiginali ye-analogi ngezikhathi ezithile futhi simele isampula ngayinye elinganisiwe ngendlela yedijithali.

Bekucatshangwa ukuthi imvamisa okuzokwenziwa ngayo lezi zilinganiso kufanele okungenani kube imvamisa ephakeme kakhulu ephindwe kabili umuntu angawezwa, futhi njengoba icishe ibe ngu-20 kHz, ngakho-ke, imvamisa enkulu kakhulu. I-44,1kHz isala iyisilinganiso sesampula esidumile. Ukubalwa kwesilinganiso samasampula kuhlotshaniswa nokusebenza kwezibalo okuyinkimbinkimbi, okuthi, kulesi sigaba solwazi lwethu lwezindlela zokuguqula, kungenzi umqondo.

Okuningi kungcono?

Konke engikushilo ngenhla kungase kubonise ukuthi ukuphakama kwemvamisa yesampula, i.e. ukulinganisa izinga lesignali ye-analog ngezikhathi ezivamile, izinga eliphezulu lokuguqulwa, ngoba - okungenani ngomqondo onembile - linembe kakhudlwana. Ingabe kuyiqiniso ngempela? Sizokwazi ngalokhu esikhathini esingangenyanga.