Kev piav qhia ntxaws ntxiv ntawm linear tswj fais fab mov lub tswv yim ua haujlwm
Peb nquag categorize tswj cov khoom siv hluav taws xob rau hauv ob pawg raws li kev ua haujlwm ntawm cov kav dej tswj kav: hloov cov khoom siv hluav taws xob tswj thiab cov khoom siv hluav taws xob tawm. Kuj tseem muaj me me Zener raj-powered fais fab mov.
Lub DC tswj fais fab mov nyob rau hauv uas lub regulator raj ua hauj lwm nyob rau hauv ib tug linear mob yog hu ua lub linear tswj fais fab mov ntawm no. Txhawm rau kom nkag siab tias lub raj hloov pauv ua haujlwm li cas hauv cov kab mob, xav txog cov hauv qab no: RW yog qhov sib txawv tsis tu ncua, lossis linear (saib qhov kev tshuaj ntsuam hauv qab). Nyob rau hauv lub switching fais fab mov, nws txawv. Lub raj xa hluav taws xob ua haujlwm nyob rau hauv ob lub xeev: rau thiab tawm: nyob rau, qhov tsis kam yog qhov me me; tawm, qhov tsis kam yog me me loj heev. Nyob rau hauv lub switching fais fab mov, peb feem ntau xa mus rau lub adjusting raj raws li ib tug switching raj. Ntawm chav kawm, lub raj ua haujlwm nyob rau hauv lub xeev on-off tsis ua li ntawd nyob rau hauv ib tug linear yam.
Ib qho qub qauv ntawm DC tswj fais fab mov yog cov linear tswj fais fab mov. Lub LDO uas nquag pom tam sim no tshwm los daws qhov teeb meem kev ua tau zoo. Txawm li cas los xij, cov kab hluav taws xob tswj hluav taws xob DC muaj cov yam ntxwv hauv qab no: cov zis hluav taws xob qis dua qhov hluav taws xob input; cov lus teb ceev ceev; cov zis ripple yog me me; lub suab nrov tsim los ntawm kev ua haujlwm tsawg; efficiency yog tsawg; thiab tsim hluav taws xob loj (tshwj xeeb tshaj yog cov khoom siv hluav taws xob muaj zog), uas ua rau lub suab nrov tsis ncaj rau lub cev.
Lub hauv paus ntsiab lus ntawm kev ua haujlwm: Cov duab hauv qab no yuav qhia tias lub zog hluav taws xob linear tswj tau li cas.
Uo=UiRL/(RW ntxiv rau RL), yog li cov zis hluav taws xob tuaj yeem hloov pauv los ntawm qhov sib txawv ntawm qhov loj ntawm RW. Thov nco ntsoov tias hauv cov qauv no, yog tias peb tsuas yog xav txog qhov sib txawv ntawm cov resistor RW tus nqi hloov, cov zis ntawm Uo tsis yog linear; Txawm li cas los xij, yog tias peb xav txog RW thiab RL, cov zis ntawm Uo yog linear. Kuj tseem nco ntsoov qhov tseeb tias peb daim duab qhia pom cov hlau lead-tawm ntawm RW mus rau sab xis es tsis yog sab laug. Daim duab ntawm sab xis tsuas yog qhia txog cov kev xav ntawm "sampling" thiab "feedback," txawm tias tsis muaj qhov txawv ntawm cov qauv; feem ntau ntawm cov khoom siv hluav taws xob tiag ua haujlwm raws li kev kuaj thiab kev tawm tswv yim. Txoj kev feedforward tsuas yog siv qee zaus hauv qab no, lossis nws tsuas yog siv los ua ib txoj hauv kev pab.
Cia peb txav mus rau: Yog tias peb hloov qhov hloov pauv hloov pauv hauv daim duab nrog lub triode lossis thaj chaw cuam tshuam transistor, thiab tswj qhov kev tawm tsam ntawm "varistor" los ntawm kev hnov qhov tso zis hluav taws xob, kom cov zis hluav taws xob tas li, peb tuaj yeem Voltage stabilization ua tiav hauv nws lub hom phiaj. Qhov no triode los yog field effect raj yog hu ua lub raj hloov vim nws yog siv los hloov cov zis voltage.
Txij li thaum lub regulator raj txuas nyob rau hauv series ntawm lub hwj chim mov thiab lub load, nws yog hu ua ib tug series tswj fais fab mov. Raws li txoj cai, kuj tseem muaj shunt-hom tswj fais fab mov, uas yog los kho cov zis voltage los ntawm kev sib txuas cov regulator raj nyob rau hauv parallel nrog lub load. Qhov kev siv hluav taws xob raug siv hluav taws xob TL431 yog shunt-hom voltage regulator. Qhov kev sib txuas hu ua parallel txhais tau hais tias zoo li lub zog hluav taws xob tswj lub raj hauv daim duab 2, "kev ruaj ntseg" ntawm lub emitter voltage ntawm lub attenuating amplifier raj yog ua kom ntseeg tau los ntawm shunting. Tej zaum daim duab no tsis cia koj pom tias nws yog "kev sib txuas ua ke", tab sis ntawm kev soj ntsuam ze dua, nws yog qhov tseeb. Txawm li cas los xij, txhua tus neeg yuav tsum tau them sai sai rau ntawm no: lub tshuab hluav taws xob hluav taws xob ntawm no ua haujlwm hauv nws cheeb tsam uas tsis yog-linear, yog li yog tias koj xav tias nws yog lub zog hluav taws xob, nws kuj yog lub zog tsis muaj hluav taws xob. Txhawm rau ua kom yooj yim rau txhua tus nkag siab, cia peb rov qab mus rau ntawm daim duab tsim nyog kom txog thaum peb tuaj yeem nkag siab qhov tseeb.
Txij li thaum lub raj kho yog sib npaug rau cov resistor, nws yuav tsim kom muaj cua sov thaum lub tam sim no ntws los ntawm lub resistor, yog li lub kho raj ua hauj lwm nyob rau hauv ib tug linear lub xeev feem ntau yuav ua kom muaj cua sov, uas ua rau tsis tshua muaj efficiency. Qhov no yog ib qho ntawm qhov tsis zoo tshaj plaws ntawm cov khoom siv hluav taws xob linear tswj. Yog xav paub ntxiv txog kev nkag siab ntau ntxiv ntawm cov khoom siv hluav taws xob linear, thov mus saib hauv phau ntawv qhia ntawm analog hluav taws xob circuits. Ntawm no peb tsuas yog pab koj kom paub meej cov ntsiab lus no thiab kev sib raug zoo ntawm lawv.
