Yuav ua li cas yog lub voltage divider

voltage dividers yog lug siv nyob rau hauv electronics vim hais tias lawv tso cai rau ib qho kev pom txoj kev uas yuav daws tau qhov teeb meem ntawm voltage kev cai. Muaj ntau ntau yam schematic kev daws teeb meem los ntawm lub simplest, xws li ib co phab ntsa teeb, kom txaus complex li ua hauj lwm ceev tswj cov laug cam normalizers windings ntawm cov mains voltage.

Yuav ua li cas yog lub voltage divider? Formulation yooj yim - yog ib tug ntaus ntawv hais tias, nyob ntawm seb cov kis ratio (configured cais) ntawm lwm yam uas lub qhov zis voltage txheeb ze rau cov tswv yim.

Nyuam qhuav pib nyob rau hauv lub khw muag khoom noj feem ntau koj yuav nrhiav tau ib lub teeb, cov phab ntsa teeb, tsim los rau ob lub teeb. Nws feature tshwj xeeb yog hais tias lub teeb lawv tus kheej tau tsim los ua hauj lwm nrog ib tug voltage ntawm 127 volts. Tag nrho system yog kev cob cog rua rau ib tug neeg hauv tsev neeg hwj chim socket nrog 220 thiab nws ua hauj lwm ntse. Tsis txuj ci tseem ceeb! Qhov no yog hais tias cov qauv ntawm cov txuas conductors tsim tsis muaj dab tsi tab sis raws li ib tug voltage divider. Cia peb rov qab qhov yooj yim hluav taws xob kev tshawb xav, namely, thaum uas tig mus thiab serial kev twb kev txuas ntawm cov kev pab. Raws li yog lub npe hu, nyob rau hauv zaj hom switching amperage sib npaug zos, thiab cov voltage hloov (txheejtxheem Ohm txoj cai). Yog li ntawd, nyob rau hauv cov piv txwv nrog cov tib hom teeb teeb muaj kev cob cog nyob rau hauv series, uas muab ib tug txo nyob rau hauv lub mov ntawm voltage rau ob lub sij hawm (110). Tsis tas li ntawd, lub voltage divider yuav pom nyob rau hauv lub ntaus ntawv, uas tau muab lub teeb liab los ntawm ib tug kav hlau txais xov mus rau ntau yam TVs. Nyob rau hauv qhov tseeb, muaj ntau yam piv txwv.

Cia peb xav txog ib tug yooj yim voltage divider rau lub hauv paus ntawm lub ob resistors R1 thiab R2. Kuj kev cob cog rua nyob rau hauv series rau cov nyob rau cov lus xaus nkag tswv yim voltage U. Los ntawm nruab nrab point ntawm tus neeg xyuas pib txuas lub resistors, muaj ib tug ntxiv tso zis. Hais tias yog, nws puv peb hnub, ob - yog lwm terminals (nruab nrab ntawm tag nrho cov nqi ntawm cov voltage U) thiab qhov nruab nrab txoj kev U1 thiab U2.

Lub xam ntawm cov voltage divider, siv Ohm txoj kev cai. Txij li thaum kuv = U / R, U yog qhov khoom ntawm qhov tam sim no nyob rau hauv kuj. Raws li, qhov cheeb tsam R1 nrog lub voltage yog U1, thaum R2 yuav U2. Tus tam sim no ces sib npaug zos rau (serial kev twb kev txuas). Muab cov kev cai lij choj rau lub teb saw, peb pom tias lub mov yog qhov tawm ntawm cov U U1 + U2.

Yuav ua li cas yog tam sim no nyob rau hauv cov tej yam kev mob? Generalizing kab zauv, peb tau txais:

I = U / (R1 + R2).

Los ntawm no peb yuav txiav txim seb tus nqi ntawm cov voltage (U tawm) nyob rau hauv lub tso zis ntawm divider (qhov no yuav ua tau ob qho tib si U1, thiab U2):

U tawm = U * R2 / (R1 + R2).

Rau dividers nrog adjustable resistances muaj ib co tseem ceeb nta uas yuav tsum raug xam tias yog nyob rau theem ntawm kev sib hais haum, thiab nyob rau hauv lub lag luam.

Ua ntej ntawm tag nrho cov, cov ntsiab yuav siv tsis tau yuav tau kho cov voltage haib tau txais kev pab. Piv txwv li, nyob rau hauv no txoj kev uas nws yog tsis yooj yim sua rau faiv fab tso lub electric tsav. Ib tug ntawm cov yog vim li cas - nws yog resistor qhov tseem ceeb rau lawv tus kheej. Kuj kilowatts yog hais tias lawv muaj nyob, yog loj heev li dissipating ib feem impressive zog li thaum tshav kub kub.

Kev cob cog rua load kuj muaj nqis yuav tsum tsis txhob yuav tsawg tshaj li qhov hluav taws xob kuj circuitry ntawm lub divider, txwv tsis pub yuav los txheeb peev tag nrho system. Qhov tseeb tiag mas qhov txawv divider R thiab R load yuav tsum tau loj li sai tau. Nws yog ib qho tseem ceeb kom meej xaiv qhov tseem ceeb ntawm R1 thiab R2, txij li thaum ntev denominations entail ntev voltage nco, thiab yuav overheat muaj tsawg tsawg heev, nkim zog los ntawm cov cua kub.

Suav divider feem ntau xaiv tus nqi ntawm nws tam sim no lub sij hawm (e.g., 10) ib yam li cov kev cob cog rua load amperage. Ntxiv mus, kev paub txog qhov tam sim no thiab voltage, lub neej coj kuj yog xam (R1 + R2). Ntxiv cov ntxhuav tom ntej xaiv txheem qhov tseem ceeb R1 thiab R2 (nyob rau hauv view ntawm lawv lub hwj chim tuav kev txawj kom tsis txhob ntev cua kub).