Cov ncauj lus kom ntxaws ua haujlwm ntawm linear tswj fais fab mov
Raws li lub xeev ua hauj lwm ntawm lub regulating raj, peb feem ntau faib cov tswj fais fab mov rau hauv ob pawg: linear tswj fais fab mov thiab switching tswj fais fab mov. Tsis tas li ntawd, muaj lub zog me me uas siv lub raj Zener.
Cov kab hluav taws xob tswj hluav taws xob tau hais los ntawm no yog hais txog DC tswj fais fab uas lub raj regulator ua haujlwm nyob rau hauv lub xeev linear. Lub raj hloov ua haujlwm nyob rau hauv lub xeev linear, uas tuaj yeem nkag siab zoo li no: RW (saib qhov kev tshuaj ntsuam hauv qab no) yog qhov sib txawv tsis tu ncua, uas yog, linear. Nws txawv nyob rau hauv lub switching fais fab mov. Lub raj xa hluav taws xob (hauv kev hloov hluav taws xob, peb feem ntau hu rau lub raj hloov kho lub raj hloov) ua haujlwm nyob rau hauv ob lub xeev: rau thiab tawm: on - qhov tsis kam yog me me; tawm - qhov tsis kam yog me me loj. Lub raj ua haujlwm nyob rau hauv lub xeev on-off yog obviously tsis nyob rau hauv ib tug linear lub xeev.
Lub linear tswj fais fab mov yog ib hom DC tswj fais fab mov uas tau siv ua ntej. Cov yam ntxwv ntawm linear regulated DC fais fab mov yog: cov zis voltage yog qis dua qhov input voltage; cov lus teb ceev ceev, cov zis ripple yog me me; lub suab nrov tsim los ntawm kev ua haujlwm tsawg; qhov ua tau zoo yog tsawg (LDO uas feem ntau pom tam sim no tshwm los daws qhov teeb meem kev ua haujlwm); Kev tsim hluav taws xob loj (tshwj xeeb tshaj yog cov khoom siv hluav taws xob siab), uas ua rau lub suab nrov tsis ncaj rau lub cev.
Lub hauv paus ntsiab lus ntawm kev ua haujlwm: Cia peb xub siv cov duab hauv qab no los qhia txog lub hauv paus ntsiab lus ntawm cov kab hluav taws xob tswj hluav taws xob los tswj qhov hluav taws xob.
Raws li pom nyob rau hauv daim duab hauv qab no, qhov sib txawv resistor RW thiab load resistor RL tsim ib qhov hluav taws xob faib hluav taws xob Circuit Court, thiab cov zis voltage yog:
Uo=Ui × RL/(RW ntxiv rau RL), yog li los ntawm kev kho qhov loj ntawm RW, cov zis hluav taws xob tuaj yeem hloov pauv. Thov nco ntsoov tias hauv cov qauv no, yog tias peb tsuas saib tus nqi hloov pauv ntawm qhov hloov pauv hloov RW, cov zis ntawm Uo tsis yog linear, tab sis yog peb saib RW thiab RL ua ke, nws yog linear. Tsis tas li ntawd nco ntsoov tias peb daim duab tsis kos cov hlau lead-tawm ntawm RW mus rau sab laug, tab sis mus rau sab xis. Txawm hais tias tsis muaj qhov sib txawv ntawm cov qauv, cov duab kos ntawm sab xis tsuas yog qhia txog cov ntsiab lus ntawm "sampling" thiab "feedback"-- feem ntau ntawm cov khoom siv hluav taws xob tiag tiag ua haujlwm nyob rau hauv hom sampling thiab tawm tswv yim hauv qab no, txoj kev feedforward tsis tshua siv, los yog siv, nws tsuas yog ib txoj kev pab xwb.
Cia peb mus txuas ntxiv: Yog tias peb siv lub triode lossis field effect transistor los hloov qhov sib txawv ntawm cov resistor hauv daim duab, thiab tswj tus nqi ntawm qhov "varistor" los ntawm kev txheeb xyuas cov zis voltage, kom cov zis voltage nyob tas li, yog li peb tuaj yeem ua tau. Lub hom phiaj ntawm voltage stabilization yog tiav. Lub triode lossis field effect raj yog siv los kho cov zis hluav taws xob, yog li nws yog hu ua lub raj hloov.
Raws li pom nyob rau hauv daim duab 1, 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 Ib qho ze dua, 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.
