Hauv kev lag luam thiab hauv lub neej niaj hnub, kev siv ntau hom teeb liab converters yog ib txwm muaj. Cov cuab yeej no tuaj yeem nthuav tawm nyob rau hauv qhov dav tshaj plaws ntawm kev hloov kho kom haum rau kev daws teeb meem hauv ntau qhov chaw ntawm kev lag luam. Dab tsi ntawm cov teeb liab converters tuaj yeem raug ntaus nqi rau feem ntau? Dab tsi tuaj yeem yog cov yam ntxwv ntawm lawv txoj haujlwm?
Lub hom phiaj ntawm cov teeb liab hloov pauv yog dab tsi?
Signal converters yog cov khoom siv uas tuaj yeem nthuav tawm hauv ntau qhov kev daws teeb meem. Lub sij hawm no yog ib qho kev sib sau ua ke thiab tuaj yeem xa mus rau cov cuab yeej siv hauv ntau ntu ntawm kev lag luam thiab cais raws li cov qauv sib txawv. Cov hom phiaj tseem ceeb uas cov khoom siv hauv nqe lus nug tuaj yeem hloov pauv yog:
- hluav taws xob;
- suab;
- kub;
- technological xwm.
Txawm li cas los xij, nyob ntawm cov haujlwm uas tus neeg siv lub teeb liab hloov pauv tau ntsib, cov qauv ntawm cov khoom siv sib txuas tuaj yeem ua ke cov qauv uas ua rau ntau hom ntaub ntawv sib txawv. Kev hloov dua siab tshiab, yog li ntawd, tuaj yeem ua tiav nyob rau hauv lub moj khaum ntawm ib hom teeb liab (piv txwv li, los ntawm ib zaus mus rau lwm qhov) los yog ua ib lub tshuab uas suav nrog kev txhais lus ntawm ntau pawg ntawm cov teeb liab. Piv txwv li, hluav taws xob rau suab.
Cov khoom siv ntau tshaj plaws suav nrog lub converter ntawm analog signals rau digital (thiab vice versa, yog hais tias nws yog muab los ntawm cov qauv ntawm lub internal modules ntawm lub ntaus ntawv). Xav txog cov yam ntxwv ntawm nws txoj haujlwm.
A/D Converter
Cov cuab yeej hauv nqe lus nug yog tsim los hloov cov teeb liab analog - piv txwv li, sawv cev los ntawm cov ntsuas hluav taws xob, rau hauv daim ntawv digital (tso cai, piv txwv li, sau cov teeb liab sib thooj rau ib daim ntawv).
Ib qho ntawm cov qauv tseem ceeb rau kev ua haujlwm ntawm cov cuab yeej hauv qab kev txiav txim siab yog cov ntaub ntawv tso tawm. Nws tus nqi txiav txim siab lub teeb liab-rau- suab nrov piv.
Lwm qhov tseem ceeb uas qhia txog qhov ua tau zoo ntawm kev ua haujlwm ntawm cov cuab yeej xws li analog converter yog qhov ceev ntawm cov teeb liab tsim tawm. Ntawm cov khoom siv uas muab nws qhov kev ua tau zoo tshaj plaws yog cov uas yog hom sib npaug. Lawv tsim cov teeb liab loj ntws siv tus lej xav tau ntawm tus pins. Qhov no feature ntawm kev ua hauj lwm ntawm lub ntaus ntawv nyob rau hauv ntau rooj plaub predetermines qhov kev tso tawm ntawm cov coj converters, characterized los ntawm loj qhov ntev. Tsis tas li ntawd, analog teeb liab converters tuaj yeem muaj kev siv hluav taws xob ntau. Txawm li cas los xij, muab qhov ua tau zookev ua haujlwm ntawm cov cuab yeej no, lawv cov nta tau sau tseg feem ntau tsis suav tias yog qhov tsis txaus.
Kev hloov pauv ntawm cov teeb liab los ntawm analog mus rau cov khoom siv sib luag yog nrawm heev. Txhawm rau muab qhov nrawm dua rau cov khoom siv sib xws, koj tuaj yeem txuas ob peb yam khoom siv, kom lawv tuaj yeem ua cov teeb liab ntws los ntawm tig.
Ib qho kev xaiv rau cov kev daws teeb meem sib npaug tuaj yeem yog cov cim cim hloov pauv. Lawv zoo li ua tau tsawg dua tab sis muaj zog ntau dua. Lawv cov kev siv tej zaum yuav raug conditioned nyob rau hauv cov ntaub ntawv uas muaj ib lo lus nug ntawm kom ntseeg tau cov kis tau tus mob ntawm cov teeb liab nyob rau hauv ib tug tsawg-muaj peev xwm infrastructure, los yog nyob rau hauv cov kev tshwm sim uas ib tug ntau dua conversion npaum li cas muab los ntawm serial pab kiag li lawm yog tsis yuav tsum tau.
Nws tuaj yeem raug sau tseg tias muaj cov khoom siv sib xyaw ua ke uas sib xyaw ua haujlwm ntawm serial thiab parallel converters. Feem ntau, lawv yog cov kev daws teeb meem zoo tshaj plaws ntawm cov nqi sib ntsib thiab cov qauv kev ua haujlwm.
Peb tau sau tseg saum toj no tias analog-rau-digital converters tuaj yeem suav nrog cov qauv uas hloov cov teeb liab digital rau cov analog. Kuj tseem muaj kev sib cais ntawm cov khoom siv ntawm cov khoom siv sib xws. Cia peb kawm lawv cov yam ntxwv.
Digital-to-analog converters
Yog tias tus neeg siv muaj, piv txwv li, TV rau lub teeb liab analog, ces nwskev ua haujlwm yuav ua tau thaum lub kav hlau txais xov tsim nyog txuas nrog. Los yog raug rau kev hloov pauv ntawm thawj cov cim qhia rau hauv analog, uas lub TV no tuaj yeem paub. Lawv qhov chaw tuaj yeem, dhau los, yog tus kav hlau txais xov digital. Los yog, hloov pauv, lub teeb liab tau txais los ntawm Is Taws Nem.
Cov cuab yeej hauv nqe lus nug, yog li ntawd, hloov lub teeb liab uas muaj cov lej digital mus rau tam sim no, qhov hluav taws xob lossis tus nqi, uas tau pauv mus rau cov qauv analog rau kev ua haujlwm. Cov txheej txheem tshwj xeeb ntawm qhov kev hloov pauv no nyob ntawm hom thawj cov ntaub ntawv. Piv txwv li, yog tias peb tab tom tham txog lub suab, tom qab ntawd ntawm cov tswv yim nws feem ntau nthuav tawm hauv pulse code modulation. Yog hais tias lub hauv paus ntaub ntawv yog compressed, ces tshwj xeeb software codecs yuav siv tau los hloov cov teeb liab. Nyob rau hauv lem, tus kav hlau txais xov digital feem ntau xa cov teeb liab rau kev ua haujlwm los ntawm cov txheej txheem kho vajtse.
Cov khoom siv uas suav nrog cov hloov pauv hauv nqe lus nug tuaj yeem ntxiv nrog cov qauv rau ntau lub hom phiaj. Piv txwv li, thaum muab kev ua si ntawm lub TV tshaj tawm, lub teeb liab video amplifier tuaj yeem siv ntxiv rau cov modules uas siv los ntawm converter. Feem ntau, nws yog ib qho tsim nyog los xyuas kom meej cov duab zoo thaum hloov cov teeb liab analog rau digital. Tsis tas li ntawd, lub teeb liab video amplifier yog siv yog tias koj xav tau hloov cov duab hla qhov deb heev.
TV tsis yog thaj chaw nkaus xwb ntawm kev siv cov khoom siv hauv nqe lus nug. Cov converters sib raug tau suav nrog, piv txwv li, hauv CD player,uas kuj hloov cov teeb liab digital rau analog.
YUltrasonic transducers
Cov qeb tom ntej ntawm cov khoom siv yog ultrasonic transducer. Nws tuaj yeem raug sau tseg tias nws tuaj yeem sawv cev los ntawm cov khoom siv uas muaj ntau yam kev siv, nrog rau cov qauv kev ua haujlwm. Ntawm cov ntau yam ntawm ultrasonic transducers yog ib chav tsev submersible, uas yog tsim los xa ultrasound ntawm ib tug tej zaus mus rau hauv dej los yog lwm yam kua nruab nrab. Cov cuab yeej no tuaj yeem siv tau, piv txwv li, los ntxuav ntau yam khoom los ntawm cov khoom tsis huv - ua ib feem ntawm cov da dej siv rau kev tu ultrasonic.
Muaj lwm qhov chaw ntawm kev thov ntawm cov khoom siv txiav txim siab. Ib qho ultrasonic transducer tuaj yeem siv los tswj kev ncaj ncees ntawm qee cov qauv, kev sib txuas, los xyuas qee yam khoom rau kev puas tsuaj.
Linear thiab mem tes converters
Xav txog cov yam ntxwv ntawm kev siv cov hloov pauv, nws yuav muaj txiaj ntsig zoo rau kev saib xyuas kev faib tawm raws li lawv tau muab faib ua kab thiab mem tes. Qhov tseeb, cov qauv no qhia txog ob lub ntsiab lus tseem ceeb tshaj plaws rau kev ua haujlwm ntawm cov hloov pauv.
Cov uas yog linear tuaj yeem ua haujlwm ntawm lub hauv paus ntsiab lus ntawm analog circuitry, uas cov teeb liab hloov dua siab tshiab tau tsim ntawm qhov nrawm. Lub pulse converter xav tias muaj ntau tus sawv cev ntawm cov teeb liab ob qho tib si ntawm cov zis thiab thaum lawv ua haujlwm sab hauv. Txawm li cas los xij, yog tiasQhov kev ua haujlwm no tsuas yog ua tiav nyob rau theem sab hauv ntawm kev ua cov teeb liab, cov khoom siv sib txuas tuaj yeem tsim cov cim qhia zoo ib yam li nyob rau hauv rooj plaub thaum siv lub converter linear. Yog li, lub tswv yim ntawm linear lossis pulse processing tsuas yog xav tau nyob rau hauv cov ntsiab lus ntawm lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm cov khoom siv tseem ceeb ntawm cov khoom siv ntawm cov khoom sib xws.
Pulse converters feem ntau yog siv nyob rau hauv cov ntaub ntawv uas siv cov infrastructure yuav tsum tau ua raws li lub hwj chim teeb liab. Qhov no yog vim qhov tseeb tias qhov ua tau zoo ntawm cov khoom siv sib txuas hauv cov xwm txheej zoo li no ntau dua li thaum lawv siv los ua cov cim ntawm lub zog qis. Lwm qhov tseem ceeb ntawm kev xaiv cov kev daws teeb meem no yog kev siv cov khoom siv hluav taws xob lossis cov khoom siv hluav taws xob ua ib feem ntawm cov txheej txheem siv, uas cov pulse converters muaj qhov zoo sib xws.
Nyob rau hauv lem, ib tug linear converter yog ib tug ntaus ntawv uas yog siv nyob rau hauv lub moj khaum ntawm ib tug infrastructure nyob rau hauv uas low-power signal processing yog nqa tawm. Los yog yog tias yuav tsum tau txo lub suab nrov vim yog kev ua haujlwm ntawm lub converter. Nws yog ib qho tsim nyog sau cia tias qhov ua tau zoo ntawm cov kev daws teeb meem raws li kev xav hauv lub zog hluav taws xob tsis yog qhov zoo tshaj plaws, yog li ntawd, cov cuab yeej no feem ntau tawm hluav taws xob ntau dua li cov hloov pauv hloov pauv. Tsis tas li ntawd, lawv qhov hnyav thiab qhov ntev kuj tseem loj dua.
Tab sis, ib txoj kev lossis lwm qhov, hauv kev xyaum, kev ua haujlwm ntawm lub converter raws li lub hauv paus ntsiab lus mem tes yuav koom nrogtsim ntawm nws txoj haujlwm hloov pauv hauv daim ntawv linear. Yog li ntawd, ua ntej siv cov teeb liab tsim nyog rau hauv kev tsim kho vaj tse, lawv cov qauv sab hauv yuav tsum tau txiav txim siab rau cov txheej txheem ua tiav cov teeb liab.
ntsuas transducers
Lwm yam kev daws teeb meem yog cov transducers. Lawv cov yam ntxwv yog dab tsi? Lub ntsuas transducer yog ib qho khoom siv uas tuaj yeem nthuav tawm hauv ntau ntau yam. Dab tsi koom ua ke cov cuab yeej no yog lawv lub peev xwm los ntsuas thiab hloov qee qhov ntau.
Nws yog ib qho uas yuav tsum xav txog cov txheej txheem kev ua haujlwm ntawm kev ntsuas cov khoom siv sib xws, uas cov teeb liab tau ua tiav hauv ntau theem. Ua ntej, lub converter tau txais nws, ces hloov nws mus rau hauv tus nqi uas yuav ntsuas tau, ces transforms nws mus rau hauv ib co pab zog. Piv txwv li, yog siv analog ntsuas tam sim no transducer, ces hluav taws xob hluav taws xob hloov mus rau txhua yam zog.
Tau kawg, cov txheej txheem tshwj xeeb rau kev siv cov kev daws teeb meem tsim nyog tuaj yeem nthuav tawm hauv ntau yam. Kev siv ntsuas kev hloov pauv rau kev tshawb fawb raws li ib feem ntawm cov txheej txheem rau kev sim thiab kev tshawb fawb yog dav. Qhov sib koom ua ke feem ntau ntsuas cov transducers yog lawv qhov kev hloov pauv, ua ntej ntawm tag nrho cov, ua haujlwm nrog kev siv cov yam ntxwv zoo li qub thaum ua lossis hloov lub teeb liab. Ua tauNco ntsoov tias cov kev qhia tshwj xeeb no yuav tsis yog ib txwm npaj rau cov neeg siv kawg ntawm lub inverter. Lawv ua kom muaj ntau qhov xwm txheej yog nqa tawm hauv hom zais. Ib tug neeg, siv lub teeb liab converters tsim nyog, tau txais cov teeb liab uas yuav tsum tau, yoog rau siv ntau lub hom phiaj, ntawm cov zis.
Yog li, cov kev daws teeb meem no, raws li txoj cai, tsis yog siv los ua hom kev ywj pheej ntawm kev tsim vaj tsev. Lawv yog ib feem ntawm cov khoom siv ntau dua - piv txwv li, ntsuas automation systems hauv kev tsim khoom. Ntsuas transducers feem ntau muab faib ua 2 pawg loj - thawj thiab nruab nrab. Nws yuav muaj txiaj ntsig los xav txog qhov tshwj xeeb ntawm ob qho tib si.
Kev faib tawm ntawm kev ntsuas ntsuas transducers: thawj thiab nruab nrab cov kev daws teeb meem
Devices teej tug mus rau qeb ntawm thawj, raws li txoj cai, yog siv raws li sensors. Ntawd yog, lawv yog cov hloov pauv uas ib lossis lwm qhov ntsuas tus nqi ua ncaj qha. Cov khoom siv ntxiv tau muab cais ua qhov nruab nrab. Lawv tau muab tso rau hauv kev ntsuas kev ntsuas tam sim ntawd tom qab thawj zaug thiab tuaj yeem ua lub luag haujlwm rau kev ua haujlwm ntau txog kev hloov pauv. Cov haujlwm tshwj xeeb twg tuaj yeem ua tau los ntawm lub teeb liab theem converter ntawm cov khoom sib xws? Cov no feem ntau hu ua:
- ntsuas qhov ntsuas lub cev rau ntau qhov ntau;
- ntau yam kev hloov pauv;
- kev hloov pauv ntawm cov teeb liab digital rau hauv analog thiab vice versa;
- kev hloov pauv ua haujlwm.
Nco ntsoov qhov zoo sib xwsKev faib tawm tuaj yeem suav tias yog kev cai. Qhov no feem ntau yog vim qhov tseeb tias ob peb lub hauv paus transducers tuaj yeem nyob hauv tib lub ntsuas ntsuas. Lwm qhov laj thawj los txiav txim siab qhov kev faib tawm uas tau tham saum toj no yog qhov sib txawv ntawm cov txheej txheem, kev ntsuas tuaj yeem ua raws li cov qauv sib txawv.
Intensifier tubes
Lwm yam ntawm cov cuab yeej nrov hauv ntau qhov kev lag luam ntawm kev lag luam yog cov duab intensifier raj. Nws, zoo li lwm yam khoom siv uas tau tham saum toj no, tuaj yeem nthuav tawm hauv ntau hom qauv. Electron-optical converters yog koom ua ke los ntawm ib tug ntau txoj hauv kev ntawm kev khiav hauj lwm: nws muaj xws li kev hloov dua siab tshiab ntawm ib yam khoom tsis pom - piv txwv li, illuminated los ntawm infrared, ultraviolet los yog, piv txwv li, x-rays, mus rau hauv lub pom spectrum.
Nyob rau hauv rooj plaub no, kev ua haujlwm sib raug, raws li txoj cai, yog ua nyob rau hauv 2 theem. Hauv thawj theem, qhov pom tsis pom hluav taws xob tau txais los ntawm photocathode, tom qab ntawd nws tau hloov mus rau hauv cov teeb liab hluav taws xob. Uas yog twb nyob rau theem ob hloov dua siab tshiab rau hauv ib tug pom cov duab thiab tso tawm kom pom ntawm qhov screen. Yog tias nws yog lub khoos phis tawj saib, ces lub teeb liab tuaj yeem hloov ua ntej mus rau digital code.
Intensifier raj yog cov kev daws teeb meem uas ib txwm muab faib ua ntau tiam neeg. Cov khoom siv cuam tshuam rau thawj zaug suav nrog lub khob nqus tsev vacuum. Nws muaj photocathode thiab anode. Muaj peev xwm sib txawv ntawm lawv. Thaum thov rauQhov zoo tshaj plaws voltage converter nyob rau hauv nws tsim ib tug hluav taws xob lens muaj peev xwm tsom electron flows.
Lub cim thib ob transducers muaj cov khoom siv hluav taws xob acceleration, ua rau cov duab zoo dua qub. Cov khoom siv thib peb siv cov ntaub ntawv uas tso cai rau qhov kev nkag siab ntawm photocathode ua ib qho tseem ceeb ntawm cov khoom siv hluav taws xob-kho qhov muag los ntawm ntau dua 3 zaug.
Txoj kev ntawm cov hloov pauv hloov pauv
Lwm hom khoom siv yog cov khoom siv hluav taws xob tiv thaiv. Xav txog lawv cov yam ntxwv hauv kev nthuav dav ntxiv.
Cov transducers no tau yoog los hloov lawv tus kheej hluav taws xob tiv thaiv raws li kev cuam tshuam ntawm ib lossis lwm qhov ntsuas kom muaj nuj nqis. Lawv kuj tuaj yeem kho angular thiab linear txav. Feem ntau, cov converters no muaj nyob rau hauv automation systems nrog sensors rau siab, kub, illumination theem, thiab ntsuas qhov siv ntawm ntau hom hluav taws xob. Cov txiaj ntsig tseem ceeb ntawm cov khoom siv hluav taws xob tiv thaiv:
- kev cia siab;
- tsis muaj kev sib raug zoo ntawm qhov raug ntawm kev ntsuas thiab kev ruaj ntseg ntawm cov khoom siv hluav taws xob.
Muaj ntau ntau yam ntawm cov khoom siv cuam tshuam. Ntawm cov nrov tshaj plaws yog kub sensors. Cia peb kawm lawv cov yam ntxwv.
Resistive kub sensors
Cov teeb liab converters no muaj cov khoom uas nkag siab zoo rau kev hloov pauv ntawm qhov kub thiab txias. Yog hais tias nws nce, ces lawv kuj yuav nce. Cov cuab yeej no yog tus cwj pwm feem ntau los ntawm qhov raug siab heev. Qee qhov xwm txheej, lawv ua kom nws tuaj yeem hloov qhov ntsuas kub nrog qhov tseeb ntawm 0.026 degrees Celsius. Cov khoom siv no muaj cov khoom ua los ntawm platinum - qhov no, cov coefficient kuj yuav qis dua, lossis tooj liab.
Kev siv cov sensors tiv taus yog tus cwj pwm los ntawm ntau qhov nuances. Yog li, nws yuav tsum raug coj mus rau hauv tus account tias qhov tseem ceeb ntawm qhov excitation tam sim no nkag mus rau lub sensor nce nws qhov kub thiab txias, tab sis, tib lub sijhawm, ua kom sov cov ntsiab lus ntawm cov khoom sib txuas. Qhov no feem ntau ua rau txo qis ntawm nws qhov tseeb. Yog li ntawd, nws raug pom zoo kom ua kom pom kev zoo siab tam sim no kev ua haujlwm, suav nrog kev ntsuas tshwj xeeb. Piv txwv li, kev xam yuav siv tau, piv txwv li, lub thermal conductivity ntawm nruab nrab nyob rau hauv uas lub sensor yog siv - huab cua los yog dej. Raws li txoj cai, cov cim qhia tau pom zoo rau kev tawm dag zog tam sim no tau teeb tsa los ntawm cov tuam ntxhab ntawm cov khoom siv ntawm cov khoom sib xws. Txawm li cas los xij, lawv tuaj yeem sib txawv heev nyob ntawm cov hlau siv hauv kev tsim cov khoom siv. Tsis tas li ntawd, thaum siv cov sensors hauv nqe lus nug, nws yog ib qho tsim nyog yuav tsum coj mus rau hauv tus account xws li qhov taw qhia raws li qhov txwv tus nqi rau kev khiav hauj lwm tam sim no. Feem ntau nws kuj tau txiav txim los ntawm cov chaw tsim khoom.
Resistive sensors yog ib hom kev hloov pauv ntau tshaj plaws hauv tsev neeg. Qhov no feem ntau yog vim qhov tseem ceeb thev naus laus zis zoo ntawm ntau yam ntawm lawv ntau yam. Piv txwv li, yog tiastham txog thermistors - lawv yog cov yam ntxwv ntawm siab rhiab heev, compactness, tsis tshua muaj hnyav. Hom sensors tsim nyog tuaj yeem siv los ntsuas huab cua kub hauv ntau yam xwm txheej. Lawv ntau lawm feem ntau tsis cuam tshuam nrog cov nqi tseem ceeb. Muaj tseeb tiag, thermistors kuj muaj qhov tsis zoo - ua ntej ntawm tag nrho cov, qhov no yog qib siab ntawm nonlinearity, vim tias lawv tuaj yeem siv tau rau hauv kev xyaum hauv qhov ntsuas qhov qis qis.
Cov hom teeb liab sib xws (lawv hom thiab lub hom phiaj tuaj yeem txiav txim siab raws li cov qauv kev faib tawm sib txawv) tau siv dav hauv lub neej txhua hnub. Piv txwv li, nws yog ib qho uas muaj qhov kub thiab txias sensors uas muaj platinum thiab tooj liab ntsiab nyob rau hauv lawv muaj pes tsawg leeg:
- cov khoom siv cua sov - txhawm rau ntsuas qhov ntsuas kub ntawm cov cua txias hauv qee qhov ntawm cov khoom siv, nrog rau hauv chav cua sov;
- tshuab ntxhua khaub ncaws - txhawm rau ntsuas dej kub thiab kho kom haum rau ntau yam kev ntxuav;
- irons - zoo ib yam los xyuas kom meej qhov zoo tshaj plaws ironing kub nyob rau hauv ib qho kev ua hauj lwm hom;
- lub qhov cub hluav taws xob, nrog rau lwm yam khoom siv rau kev ua noj - tseem txhawm rau kom ntseeg tau tias lawv ua haujlwm thaum qee tus neeg siv hom tau qhib.
Rheostat converters
Lwm yam nrov ntawm cov khoom siv tiv thaiv yog rheostat converters. Lawv lub hauv paus ntsiab lus ntawm kev ua haujlwm yog ua raws li kev ntsuas hluav taws xob tiv thaivntawm ib tug los yog lwm tus neeg xyuas pib nyob rau hauv lub zog ntawm input displacement. Hauv kev xyaum, qhov transducer no suav nrog cov ntsiab lus uas tau hloov kho kom txav mus los vim qhov cuam tshuam ntawm qhov ntsuas tus nqi. Feem ntau, cov khoom siv hauv nqe lus nug tau suav nrog hauv qhov sib faib hluav taws xob lossis siv los ua ib qho tseem ceeb ntawm kev ntsuas choj.
Yog tias peb tham txog qhov zoo uas ua rau cov hloov pauv rheostat, ces cov no suav nrog:
- tsis muaj qhov cuam tshuam rau kev txav mus los;
- kev ua haujlwm siab;
- qhov me me, lub peev xwm los siv hauv kev tsim kho vaj tse ua haujlwm ntawm ob qho tib si ncaj qha thiab hloov tam sim no.
Tib lub sijhawm, cov hloov pauv hloov pauv ntawm cov khoom sib txuas tsis yog ib txwm ntseeg tau thiab ntau zaus xav tau cov peev txheej tseem ceeb los ntawm kev lag luam los tswj kev ua haujlwm.
