Yuav ua li cas txog qhov tsim ntawm high-precision AC qhov chaw tam sim no?
Rau cov neeg siv khoom siv hluav taws xob, cov hauv qab no siv tau: qhov tseeb dua cov ntaub ntawv ntsuas, qhov zoo dua. Yog tias koj xav tau cov txiaj ntsig zoo, thawj qhov yuav tsum ua yog txhim kho koj cov cuab yeej. Yog tias koj xav ntsuas cov ntaub ntawv kom raug ntau dua, koj yuav tsum ua qhov ntsuas cov ntaub ntawv ruaj khov thiab ruaj khov ua ntej, thiab koj yuav tsum xav tau cov khoom siv hluav taws xob kom raug.
Piv txwv li, txhawm rau txhawm rau ntes tus nqi analog ntawm lub ntsuas hluav taws xob tiv thaiv, yuav tsum muaj lub zog txhim khu kev qha yog tias qhov ntsuas yuav raug. Nws tuaj yeem yog qhov hluav taws xob hluav taws xob uas hnov qhov hloov pauv tam sim no, lossis qhov chaw tam sim no uas hnov qhov hloov pauv ntawm qhov hluav taws xob. Piv nrog rau tom kawg, nws yog qhov yooj yim dua ntawm chav kawm los muab qhov chaw tam sim no thiab tom qab ntawd kuaj xyuas tus nqi ntawm qhov hloov pauv voltage tshwm sim los ntawm kev hloov pauv ntawm cov sensor tsis kam.
Tom ntej no, kuv yuav ua kom paub cov qauv kev tsom xam ntawm high-precision AC qhov chaw tam sim no.
AC qhov chaw tam sim no
Rau qhov Circuit Court no, qhov twg R5=R6, R1=R2, lub input davhlau ya nyob twg yog 1V siv voltage input.
V1=(1VREF plus V5)/2. Los ntawm lub voj voog luv luv ntawm op-amp, V2=V1, tam sim no ntws los ntawm R1 yog sib npaug rau V2 / R1.
Los ntawm kev sib cais virtual ntawm kev ua haujlwm amplifier, qhov tam sim no ntws mus rau hauv inverting input ntawm op1 yog xoom, yog li tam sim no ntws los ntawm R1 yog sib npaug rau tam sim no ntws los ntawm R2, qhov twg (V3-V2)/R{{ 5}} V2/R1. Thiab R1=R2, yog li V3=2V2=2V1=1VREF plus V5.
Saib dua op2 ntawm op amp, V5=V4. Yog li, tam sim no los ntawm R4 yog (V3-V4)/R4=(1VREF plus V5-V4)/R4, thiab V4=V5, yog li tam sim no los ntawm R4 yog qhov tsis tu ncua 1VREF/R4.
Paub los ntawm lub davhlau ya nyob twg virtual ntawm kev ua haujlwm amplifier, qhov tam sim no ntws mus rau hauv qhov zoo tawm tswv yim davhlau ya nyob twg ntawm op2 yog hais txog 0, yog li tam sim no ntws los ntawm R4 yog sib npaug rau cov zis tam sim no I0, uas yog, qhov tsis tu ncua tam sim no I0=1VREF/R4 tau paub.
