Voltage regulators coj ib qho input voltage thiab tsim ib tug tswj cov zis voltage ntawm ib tug taag los yog adjustable theem. Qhov kev tswj tsis siv neeg no ntawm cov zis hluav taws xob theem yog ua haujlwm sib txawv los ntawm ntau hom kev tswj hluav taws xob.
Type of Voltage Regulators
Tus nqi pheej yig tshaj plaws thiab feem ntau yog hom kev tswj hluav taws xob yooj yim tshaj plaws los siv yog cov kab hluav taws xob hluav taws xob. Linear regulators yog compact thiab feem ntau siv nyob rau hauv low-voltage, low-power systems. Hloov cov regulators muaj txiaj ntsig zoo dua li cov kab hluav taws xob hluav taws xob, tab sis nyuaj ua hauj lwm nrog thiab kim dua. Zener diodes yog pheej yig thiab yooj yim siv tab sis tsis tshua muaj txiaj ntsig zoo li cov kab tswj hwm kab.
Linear Regulators
Ib txoj hauv kev yooj yim tshaj plaws los muab lub zog ruaj khov rau cov khoom siv hluav taws xob yog siv tus qauv 3-pin linear voltage regulator, xws li LM7805, uas muab 5-volt, 1-amp tso zis nrog ib qho input voltage. txog li 36 volts (nyob ntawm tus qauv).
Linear regulators ua hauj lwm los ntawm kev kho qhov sib npaug series tsis kam (ESR) ntawm tus regulator raws li ib tug tawm tswv yim voltage, qhov tseem ceeb los ua ib tug voltage divider circuit. Qhov no tso cai rau tus neeg tswj hwm tso tawm qhov hluav taws xob tas li tsis hais txog qhov tam sim no thauj khoom tso rau ntawm nws, mus txog nws lub peev xwm tam sim no.
Ib qho ntawm qhov tsis zoo rau cov kab hluav taws xob hluav taws xob yog qhov tsawg kawg nkaus voltage poob, uas yog 2.0 volts ntawm tus qauv LM7805 linear voltage regulator. Qhov no txhais tau hais tias kom tau txais qhov ruaj khov 5 volts tso zis, tsawg kawg yog 7-volt input yuav tsum tau. Qhov hluav taws xob poob qis no ua lub luag haujlwm loj hauv lub hwj chim dissipated los ntawm linear regulator, uas yuav tsum dissipate yam tsawg 2 watts yog hais tias nws muab ib tug 1-amp load (2-volt voltage poob lub sij hawm 1 amp).
Lub zog dissipation zuj zus tuaj vim qhov sib txawv ntawm cov tswv yim thiab cov zis hluav taws xob nthuav dav. Piv txwv li, thaum lub 7-volt qhov chaw tswj rau 5 volts xa 1 amp dissipates 2 watts los ntawm cov linear regulator, ib tug 10-volt qhov chaw tswj rau 5 volts xa tib lub tam sim no dissipates 5 watts, ua tus regulator tsuas yog 50% npaum.
Switching Regulators
Linear regulators yog cov kev daws teeb meem zoo rau kev siv hluav taws xob tsawg, tus nqi qis uas qhov sib txawv ntawm qhov kev tawm tswv yim thiab cov zis qis, thiab tsis tas yuav tsum muaj hwj chim ntau. Qhov loj tshaj downside rau linear regulators yog tias cov no tsis muaj txiaj ntsig, uas yog qhov chaw hloov cov tswj hwm los ua si.
Thaum xav tau kev ua haujlwm siab, lossis ntau yam ntawm cov khoom siv hluav taws xob xav tau, lub tshuab hloov pauv yuav yog qhov kev xaiv zoo tshaj plaws. Switching voltage regulators muaj hwj chim ua tau zoo ntawm 85% los yog zoo dua piv rau linear voltage regulator efficiency uas feem ntau qis dua 50%.
Hloov cov tswj hwm feem ntau xav tau cov khoom ntxiv ntawm cov tswj hwm kab. Qhov tseem ceeb ntawm cov khoom muaj feem cuam tshuam rau tag nrho cov kev ua tau zoo ntawm kev hloov regulators tshaj li linear regulators. Kuj tseem muaj cov teeb meem tsim qauv hauv kev siv cov tswj kev hloov pauv kom zoo yam tsis muaj kev cuam tshuam kev ua haujlwm ntawm lub voj voog uas tshwm sim los ntawm cov suab nrov hluav taws xob uas tus tswj hwm tsim tawm.
Zener Diodes
Ib txoj hauv kev yooj yim tshaj plaws los tswj qhov hluav taws xob yog nrog Zener diode. Thaum cov kab hluav taws xob tswj hwm feem ntau yog qhov yooj yim hauv kev tsim, Zener diode muab kev tswj hwm qhov hluav taws xob txaus hauv ib feem.
Vim tias Zener diodes shunt tag nrho cov hluav taws xob ntxiv tshaj nws qhov kev tawg hluav taws xob tawg mus rau hauv av, nws tuaj yeem siv los ua tus tswj hluav taws xob yooj yim nrog cov zis hluav taws xob rub tawm thoob plaws cov thawj coj ntawm Zener diode.
Txawm li cas los xij, Zeners feem ntau muaj peev xwm tswj tau lub zog, uas txwv cov no rau cov ntawv siv hluav taws xob tsawg nkaus xwb. Thaum siv Zener diodes hauv qhov no, nws yog qhov zoo tshaj los txwv lub zog muaj zog uas tuaj yeem ntws los ntawm Zener los ntawm kev xaiv cov khoom siv kom zoo.
