1. Lub tshuab hluav taws xob hloov pauv yog dab tsi?
Hloov fais fab mov yog ib yam khoom siv hluav taws xob uas siv cov tshuab hluav taws xob niaj hnub siv hluav taws xob los tswj lub sij hawm sib piv ntawm kev hloov mus rau thiab tawm kom tswj tau qhov hluav taws xob ruaj khov. Hloov cov khoom siv hluav taws xob feem ntau yog tsim los ntawm pulse width modulation (PWM) tswj ICs thiab MOSFETs.
Cov khoom siv hluav taws xob hloov pauv yog txheeb ze rau cov khoom siv hluav taws xob linear. Nws cov input davhlau ya nyob twg ncaj qha rectifies tus alternating tam sim no rau hauv ncaj qha tam sim no, thiab ces nyob rau hauv qhov kev txiav txim ntawm high-frequency oscillation circuit, lub hloov raj siv los tswj lub on thiab tawm ntawm tam sim no los tsim ib tug high-frequency mem tes tam sim no. Nrog kev pab los ntawm inductors (high-frequency transformers), ruaj khov low-voltage direct tam sim no tso zis.
Txij li qhov loj ntawm cov tub ntxhais sib nqus ntawm lub transformer yog inversely proportional rau lub square ntawm kev khiav hauj lwm zaus ntawm lub switching fais fab mov, qhov ntau zaus, qhov me me ntawm cov tub ntxhais. Nyob rau hauv txoj kev no, lub transformer tuaj yeem txo qis heev, thiab qhov hnyav thiab ntim ntawm cov khoom siv hluav taws xob tuaj yeem raug txo. Thiab vim hais tias nws ncaj qha tswj DC, qhov ua tau zoo ntawm cov khoom siv hluav taws xob no ntau dua li ntawm cov khoom siv hluav taws xob tawm. Qhov no txuag lub zog, yog li nws nyiam los ntawm tib neeg. Tab sis nws kuj muaj qhov tsis txaus, uas yog, lub voj voog yog qhov nyuaj, kev saib xyuas yog qhov nyuaj, thiab cov pa phem rau hauv Circuit Court yog qhov hnyav. Lub hwj chim mov tsis muaj suab nrov thiab tsis haum rau qee qhov hluav taws xob qis.
2. Cov yam ntxwv ntawm kev hloov hluav taws xob
Hloov cov khoom siv hluav taws xob feem ntau yog tsim los ntawm pulse width modulation (PWM) tswj ICs thiab MOSFETs. Nrog rau kev txhim kho thiab kev tsim kho tshiab ntawm cov tshuab hluav taws xob hluav taws xob, tam sim no hloov hluav taws xob hloov pauv tau dav siv hauv yuav luag txhua yam khoom siv hluav taws xob feem ntau vim nws qhov me me, lub teeb yuag thiab kev ua haujlwm siab, thiab nws qhov tseem ceeb yog qhov tseeb.
Peb, kev faib tawm ntawm kev hloov hluav taws xob
Raws li txoj kev hloov khoom siv txuas nrog hauv Circuit Court, lub zog hloov hluav taws xob tuaj yeem muab faib ua peb pawg: series hloov hluav taws xob, sib txuas hloov hluav taws xob, thiab hloov hluav taws xob hloov hluav taws xob.
Ntawm lawv, transformer-hom switching fais fab mov tuaj yeem muab faib ntxiv rau hauv: thawb-rub, ib nrab-bridge, tag nrho-bridge, thiab lwm yam. Raws li qhov excitation ntawm transformer thiab theem ntawm cov zis voltage, nws yuav muab faib ua. : pem hauv ntej hom, flyback hom, ib hom excitation thiab ob hom excitation.
Plaub, qhov sib txawv ntawm kev hloov hluav taws xob thiab cov khoom siv hluav taws xob zoo tib yam
Cov khoom siv hluav taws xob zoo ib yam yog cov khoom siv hluav taws xob linear, thiab cov khoom siv hluav taws xob linear xa mus rau cov khoom siv hluav taws xob uas lub tshuab hluav taws xob ua haujlwm hauv lub xeev linear. Txawm li cas los xij, nws txawv hauv kev hloov hluav taws xob. Lub raj xa hluav taws xob (hauv kev hloov hluav taws xob, peb feem ntau hu ua lub raj hloov kho raws li lub raj hloov) ua haujlwm nyob rau hauv ob lub xeev: ntawm-qhov tsis kam yog me me, thiab tawm-qhov tsis kam yog siab heev. loj.
Hloov fais fab mov yog ib yam tshiab ntawm lub hwj chim mov. Nws muaj qhov zoo ntawm kev ua haujlwm siab, lub teeb yuag, voltage nce thiab txo qis, thiab lub zog tso zis siab. Tab sis vim hais tias lub voj voog ua haujlwm hauv lub xeev hloov, lub suab nrov kuj loj.
5. Piv txwv: step-down switching power supply
Cia' s luv luv tham txog lub hauv paus ntsiab lus ntawm kev ua hauj lwm ntawm kauj ruam-down switching fais fab mov: lub Circuit Court yog tsim los ntawm cov keyboards (triodes los yog field effect tubes nyob rau hauv lub tiag tiag Circuit Court), freewheeling diodes, lub zog cia inductors, lim capacitors , lwm.
Thaum lub kaw lus kaw, cov khoom siv hluav taws xob muab lub zog rau cov khoom thauj los ntawm kev hloov pauv thiab inductor, thiab khaws ib feem ntawm lub zog hluav taws xob hauv inductor thiab capacitor. Vim yog tus kheej-inductance ntawm inductor, qhov tam sim no nce kuj maj mam tom qab qhov hloov pauv, uas yog, cov zis tsis tuaj yeem ncav cuag tus nqi hluav taws xob tam sim ntawd.
Tom qab ib lub sij hawm ntawm lub sij hawm, qhov hloov mus yog muab tua. Vim yog tus kheej-inductance ntawm tus inductor (nws tuaj yeem pom tau tias qhov tam sim no hauv inductor muaj qhov cuam tshuam inertial), tam sim no hauv Circuit Court yuav nyob twj ywm tsis hloov, uas yog, txuas ntxiv ntws los ntawm sab laug mus rau sab xis. Qhov tam sim no ntws los ntawm kev thauj khoom, rov qab los ntawm cov xaim hauv av, ntws mus rau lub anode ntawm lub freewheeling diode, dhau los ntawm diode, thiab rov qab mus rau sab laug kawg ntawm inductor, yog li tsim lub voj voog.
Cov zis hluav taws xob tuaj yeem tswj tau los ntawm kev tswj xyuas lub sijhawm thaum lub kaw lus kaw thiab qhib (piv txwv li PWM-pulse width modulation). Yog tias cov zis hluav taws xob raug kuaj pom los tswj lub sijhawm rau thiab tawm kom cov zis hluav taws xob tsis tu ncua, qhov no ua tiav lub hom phiaj ntawm qhov hluav taws xob stabilization.
Ordinary fais fab mov thiab hloov fais fab mov yog tib yam nyob rau hauv uas lawv tag nrho cov muaj voltage regulators, uas siv lub tswv yim txoj cai rau voltage tswj. Qhov txawv yog tias cov khoom siv hluav taws xob hloov pauv siv cov raj hloov pauv rau kev hloov kho, thaum cov khoom siv hluav taws xob zoo tib yam feem ntau siv linear amplification cheeb tsam ntawm triode rau kev hloov kho. Hauv kev sib piv, kev siv hluav taws xob ntawm kev hloov hluav taws xob yog qhov tsawg, daim ntawv thov ntau ntawm AC voltage yog dav, thiab ripple coefficient ntawm cov zis DC yog qhov zoo dua. Qhov tsis zoo yog qhov hloov pauv mem tes cuam tshuam.
Lub hauv paus ntsiab lus ntawm kev ua haujlwm tseem ceeb ntawm ib nrab choj hloov hluav taws xob yog qhov hloov pauv ntawm tus choj sab saud thiab tus choj qis (lub raj hloov yog VMOS thaum zaus siab) tig rau hauv lem. Ua ntej, tam sim no ntws los ntawm tus choj sab sauv hloov lub raj, thiab kev ua haujlwm ntawm lub inductor yog siv los sau cov hluav taws xob hluav taws xob. Nyob rau hauv lub kauj, lub hloov raj ntawm tus choj sab sauv yog thaum kawg tua, thiab lub hloov raj ntawm tus choj qis yog qhib. Lub inductor kauj thiab lub capacitor txuas ntxiv muab lub zog rau sab nraud. Tom qab ntawd tua tus choj qis dua lub raj, tom qab ntawd tig rau ntawm tus choj sab sauv kom cia qhov tam sim no nkag mus, thiab rov ua li no. Vim tias ob lub raj hloov pauv tau hloov pauv thiab tawm hauv lem, nws yog hu ua switching power supply.
Cov khoom siv hluav taws xob linear txawv. Vim tias tsis muaj kev cuam tshuam kev hloov pauv, cov kav dej xa dej tau tso dej tawm. Yog tias muaj ntau dhau, nws yuav ntws tawm. Qhov no yog qhov peb feem ntau pom tias qee cov kab hluav taws xob hluav taws xob hluav taws xob regulator ua kom muaj cua sov ntau. Lub zog hluav taws xob inexhaustible yog txhua yam hloov mus rau hauv lub zog hluav taws xob. Los ntawm qhov kev pom no, kev hloov pauv kev ua haujlwm ntawm cov khoom siv hluav taws xob linear tsawg heev, thiab thaum tshav kub kub, lub neej ntawm cov khoom siv yog khi kom txo qis, uas yuav cuam tshuam rau qhov kawg ntawm kev siv.
Rau. Qhov sib txawv tseem ceeb: kev ua haujlwm
Lub hwj chim hloov raj ntawm cov khoom siv hluav taws xob linear ib txwm ua haujlwm hauv thaj chaw amplifying, thiab tam sim no ntws los ntawm kev txuas mus ntxiv. Vim yog lub zog loj poob ntawm lub raj hloov kho, yuav tsum muaj lub hwj chim hloov kho lub raj loj dua thiab yuav tsum muaj lub tshuab hluav taws xob loj. Thaum tshav kub kub yog qhov hnyav thiab qhov ua tau zoo tsawg heev, feem ntau 40% mus rau 60% (nws yuav tsum tau hais tias nws yog cov khoom siv hluav taws xob zoo heev).
Txoj kev ua hauj lwm ntawm linear fais fab mov yuav tsum tau ib tug voltage txo cov cuab yeej hloov los ntawm high voltage mus rau tsawg voltage. Feem ntau, nws yog ib qho kev hloov pauv, tab sis kuj tseem muaj lwm yam xws li KX cov khoom siv hluav taws xob, uas yog tom qab ntawd kho kom tsim tawm qhov hluav taws xob DC. Nyob rau hauv txoj kev no, lub ntim kuj loj, kuj hnyav, tsis tshua muaj efficiency, thiab loj thaum tshav kub kub tsim; tab sis nws kuj muaj qhov zoo: me me ripple, kev hloov pauv zoo, kev cuam tshuam me me, haum rau siv nrog analog circuits / ntau yam amplifiers, thiab lwm yam.
Cov cuab yeej hluav taws xob ntawm lub zog hloov hluav taws xob ua haujlwm hauv lub xeev hloov pauv. Thaum qhov hluav taws xob tau hloov kho, lub zog tau khaws cia ib ntus los ntawm inductance coil, kom nws qhov kev poob qis me me, qhov ua tau zoo yog siab, thiab qhov yuav tsum tau ua kom sov dissipation tsawg, tab sis nws muaj qhov hloov pauv thiab lub zog cia inductance. Kuj tseem muaj cov kev xav tau siab dua los siv cov ntaub ntawv nrog qhov poob qis thiab siab permeability. Nws transformer tsuas yog ib lo lus me me xwb. Tag nrho cov efficiency yog nyob nruab nrab ntawm 80% thiab 98%. Lub zog hloov hluav taws xob muaj kev ua haujlwm siab tab sis me me, tab sis piv nrog cov khoom siv hluav taws xob tawm, nws cov ripple thiab voltage thiab tam sim no hloov tus nqi raug txo rau qee yam.