4-20mA yog dab tsi?
4-20mA DC (1-5V DC) teeb liab tus qauv yog txhais los ntawm International Electrotechnical Commission (IEC) thiab siv rau cov teeb liab analog hauv kev tswj cov txheej txheem.
Feem ntau, lub teeb liab tam sim no rau cov twj paj nruag thiab cov ntsuas tau teem rau 4-20mA, nrog 4mA sawv cev rau qhov tsawg kawg nkaus tam sim no thiab 20mA sawv cev rau qhov siab tshaj plaws tam sim no.
Vim li cas cov zis tam sim no?
Hauv kev lag luam chaw, siv lub teeb liab amplifier rau qhov xwm txheej thiab xa cov teeb liab hla qhov ntev uas siv cov teeb liab voltage tuaj yeem ua rau ntau yam teeb meem.Ua ntej, qhov hluav taws xob hluav taws xob xa tawm ntawm cov kab hluav taws xob tuaj yeem raug cuam tshuam rau lub suab nrov.Qhov thib ob, qhov kev faib tawm tsis kam ntawm cov kab sib kis tuaj yeem ua rau muaj hluav taws xob poob.Thib peb, muab lub zog rau lub teeb liab amplifier hauv thaj chaw tuaj yeem nyuaj.
Txhawm rau daws cov teeb meem no thiab txo qhov cuam tshuam ntawm lub suab nrov, tam sim no yog siv los xa cov teeb liab vim nws tsis tshua muaj suab nrov.Lub voj 4-20mA tam sim no siv 4mA los sawv cev xoom teeb liab thiab 20mA los sawv cev tag nrho cov teeb liab, nrog cov teeb liab hauv qab 4mA thiab siab dua 20mA siv rau ntau yam teeb meem txhaum cai.
Vim li cas peb thiaj siv 4-20mA DC (1-5V DC)?
Cov cuab yeej siv hauv teb tuaj yeem siv tau ob txoj hlua hluav taws xob, qhov twg cov khoom siv hluav taws xob thiab kev thauj khoom tau txuas nrog hauv cov lus sib txuas, thiab tsuas yog ob lub xov hlau siv rau kev sib txuas lus thiab lub zog ntawm lub tshuab xa hluav taws xob thiab cov cuab yeej hauv chav tswj.Siv lub teeb liab 4mA DC raws li qhov pib tam sim no muab kev ua haujlwm zoo li qub rau lub tshuab xa hluav taws xob, thiab teeb tsa hluav taws xob xoom ntawm 4mA DC, uas tsis sib haum nrog cov neeg kho tshuab xoom taw tes, tso cai rau kev tshawb nrhiav qhov txhaum xws li hluav taws xob poob thiab cable tawg. .Tsis tas li ntawd, ob txoj kab hluav taws xob yog qhov tsim nyog rau kev siv cov teeb meem kev nyab xeeb, pab tiv thaiv tawg.
Cov cuab yeej tswj chav siv hluav taws xob sib txuas hluav taws xob sib txuas, qhov twg cov twj paj nruag uas koom nrog tib qho kev tswj hwm sib koom ua ke, ua kom yooj yim rau kev ntsuas ntsuas, hloov kho, khoos phis tawj cuam tshuam, thiab lub tswb nrov.
Yog vim li cas siv 4-20mA DC rau cov teeb liab kev sib txuas lus ntawm teb cov twj paj nruag thiab cov cuab yeej tswj chav tswj yog tias qhov kev ncua deb ntawm lub tshav pob thiab chav tswj yuav yog qhov tseem ceeb, ua rau muaj kev tiv thaiv kab mob siab dua.Kev xa hluav taws xob xaim hluav taws xob dhau mus ntev tuaj yeem ua rau muaj qhov yuam kev tseem ceeb vim qhov poob qis los ntawm cov kab hluav taws xob tsis kam thiab cov khoom siv tawm ntawm cov khoom siv tau txais.Siv lub teeb liab tam sim no rau cov chaw taws teeb kis tau tus mob kom ntseeg tau tias tam sim no nyob rau hauv lub voj tseem tsis hloov tsis hais lub cable ntev npaum li cas, lav qhov tseeb kis tau tus mob.
Yog vim li cas rau kev siv 1-5V DC teeb liab rau kev sib txuas ntawm cov cuab yeej hauv chav tswj yog los pab txhawb ntau yam twj paj nruag uas tau txais tib lub teeb liab thiab pab hauv kev xaim thiab tsim ntau yam kev tswj xyuas.Yog tias qhov chaw tam sim no siv los ua cov teeb liab sib cuam tshuam, thaum ntau lub twj paj nruag tau txais tib lub teeb liab ib txhij, lawv cov tswv yim tawm tsam yuav tsum tau txuas nrog hauv koob.Qhov no yuav tshaj qhov muaj peev xwm ntawm cov khoom xa tawm, thiab cov teeb liab hauv av muaj peev xwm ntawm cov cuab yeej txais yuav txawv, qhia kev cuam tshuam thiab tiv thaiv kev siv hluav taws xob hauv nruab nrab.
Siv lub teeb liab qhov hluav taws xob rau kev sib tshuam yuav tsum hloov lub teeb liab tam sim no siv rau kev sib txuas lus nrog cov cuab yeej teb rau hauv lub teeb liab voltage.Txoj kev yooj yim tshaj plaws yog txuas tus qauv 250-ohm resistor nyob rau hauv cov kab hluav taws xob tam sim no, hloov 4-20mA DC rau 1-5V DC.Feem ntau, txoj haujlwm no ua tiav los ntawm lub tshuab xa tawm.
Daim duab no siv 250-ohm resistor los hloov 4-20mA tam sim no teeb liab mus rau 1-5V voltage teeb liab, thiab tom qab ntawd nws siv RC lim thiab diode txuas nrog microcontroller's AD conversion pin.
"Ntawm no txuas ib daim duab qhia chaw yooj yim rau kev hloov lub teeb liab 4-20mA tam sim no rau hauv lub teeb liab voltage:
Vim li cas lub transmitter tau xaiv los siv 4-20mA DC teeb liab rau kev sib kis?
1. Kev txiav txim siab txog kev nyab xeeb rau qhov chaw muaj kev phom sij: Kev nyab xeeb hauv qhov chaw muaj kev phom sij, tshwj xeeb tshaj yog rau cov cuab yeej tawg, yuav tsum txo qis kev siv hluav taws xob zoo li qub thiab lub zog tsim nyog los ua kom cov cuab yeej ua haujlwm.Transmitters uas tso zis 4-20mA DC tus qauv teeb liab feem ntau siv 24V DC fais fab mov.Kev siv DC voltage feem ntau yog vim nws tshem tawm qhov xav tau ntawm cov capacitors loj thiab inductors thiab tsom mus rau kev faib cov peev txheej thiab inductance ntawm kev sib txuas ntawm cov xaim hluav taws xob thiab cov cuab yeej tswj chav tsev, uas yog qis dua qhov hluav taws xob tam sim no ntawm hydrogen gas.
2. Kev xa tawm tam sim no yog qhov nyiam tshaj qhov hluav taws xob: Yog tias qhov kev ncua deb ntawm thaj chaw thiab chav tswj yog qhov tseem ceeb, kev siv cov khoom siv hluav taws xob hluav taws xob rau kev sib kis tau tuaj yeem ua kom paub qhov yuam kev tseem ceeb vim qhov kev poob qis los ntawm cov kab hluav taws xob thiab cov tswv yim. tsis kam ntawm cov cuab yeej txais.Siv lub teeb liab tam sim no rau cov chaw taws teeb kis tau tus mob kom ntseeg tau tias tam sim no nyob rau hauv lub voj tseem nyob tas li, tsis hais qhov ntev ntawm cable, yog li tswj kev sib kis tau raug.
3. Kev xaiv ntawm 20mA raws li qhov siab tshaj plaws tam sim no: Kev xaiv ntawm qhov siab tshaj plaws tam sim no ntawm 20mA yog nyob ntawm kev xav txog kev nyab xeeb, kev ua tau zoo, kev siv hluav taws xob, thiab tus nqi.Cov cuab yeej pov thawj tawg tsuas tuaj yeem siv tsis tshua muaj hluav taws xob thiab tsis tshua muaj tam sim no.4-20mA tam sim no thiab 24V DC muaj kev nyab xeeb rau kev siv thaum muaj cov pa taws kub hnyiab.Lub ignition tam sim no rau hydrogen gas nrog 24V DC yog 200mA, ho siab tshaj 20mA.Tsis tas li ntawd, cov yam ntxwv xws li kev ncua deb ntawm qhov chaw tsim khoom, kev thauj khoom, kev siv hluav taws xob, cov khoom siv hluav taws xob, thiab cov khoom siv hluav taws xob yuav tsum raug coj mus rau hauv tus account.
4. Kev xaiv ntawm 4mA raws li qhov pib tam sim no: Feem ntau cov transmitters uas tso zis 4-20mA ua haujlwm nyob rau hauv ob-xaim system, qhov twg lub hwj chim mov thiab load yog txuas nrog nyob rau hauv series nrog ib tug ntau point, thiab tsuas yog ob lub xov hlau yog siv rau cov teeb liab kev sib txuas lus. thiab fais fab mov nruab nrab ntawm lub teb transmitter thiab tswj chav ntsuas ntsuas.Kev xaiv ntawm 4mA pib tam sim no yog qhov tseem ceeb rau lub transmitter Circuit Court ua haujlwm.Ib qho 4mA pib tam sim no, tsis yog coinciding nrog lub tshuab xoom point, muab ib qho "active zero point" uas pab txheeb xyuas qhov tsis zoo xws li lub zog poob thiab cable tawg.
Kev siv 4-20mA cov cim qhia ua kom muaj kev cuam tshuam tsawg, kev nyab xeeb, thiab kev ntseeg tau, ua rau nws siv dav hauv cov ntawv thov kev lag luam.Txawm li cas los xij, lwm cov teeb liab tawm tswv yim, xws li 3.33mV / V, 2mV / V, 0-5V, thiab 0-10V, kuj yog siv los tswj cov teeb liab sensor zoo dua thiab txhawb ntau lub tshuab tswj.
Post lub sij hawm: Sep-18-2023