Lub luag haujlwm ntawm shunt
Ib qho shunt feem ntau yog tus nqi ruaj khov uas tsis muaj zog siv los nthuav dav qhov tam sim no. Feem ntau txuas nrog kev sib txuas nrog lub kauj ntawm lub ammeter lossis galvanometer. Lub shunt ua haujlwm raws li seb nws puas yog DC tam sim no. Yog hais tias nws yog DC tam sim no, lub shunt feem ntau yuav txais ib qho kev nthuav dav uas tsis muaj qhov tsis kam, thiab tom qab ntawd ntsuas qhov hluav taws xob tsim tawm ntawm ob qho kawg ntawm cov resistor thaum tam sim no dhau los ntawm cov resistor. Nws yog feem ntau txuas nrog nyob rau hauv parallel. Muaj ob hom kev sib txuas sab hauv thiab kev sib txuas sab nraud ntawm lub kauj vab ntawm ammeter lossis galvanometer. Lub shunt yog qhov tseem ceeb ntawm tus resistor nrog tus nqi qis heev. Thaum DC tam sim no dhau los ntawm shunt, lub shunt yuav tsim ib qho hluav taws xob poob, yog li muab cov zaub rau DC ammeter. Txawm li cas los xij, nws yuav tsum tau muab sau tseg tias shunt thiab ammeter yog sib npaug thiab tsis tuaj yeem tsis meej pem. Lub shunt yog ib qho resistor uas tuaj yeem dhau qhov tam sim no loj heev. Feem ntau siv ammeters ntawm 15A, 20A thiab 35A yuav tsum muaj shunt. Lub impedance ntawm shunt=tag nrho-scale voltage ntawm lub 'meter' taub hau / lub tag nrho-scale tam sim no ntawm lub 'meter' taub hau, xws li ib tug 20A ammeter. Shunt resistance=75mv × 10-3/20A=0.00375. Tom qab qhov impedance tsis tas li, raws li Ohm txoj cai U=IR, tam sim no yog proportional rau qhov voltage. Qhov tam sim no yog linear thiab voltage yog linear. Yog li peb tuaj yeem siv lub voltmeter nrog qhov ntsuas tag nrho ntawm 75mv los tso saib tam sim no. Yog li, lub ammeter peb siv yog qhov tseeb voltmeter. Shunts tau dav siv los nthuav cov kev ntsuas tam sim no ntawm cov twj paj nruag. Muaj cov nqi ruaj khov thiab qhov tseeb alloy resistors, uas tuaj yeem siv rau hauv cov twj paj nruag, kev sib txuas lus, tshuab hluav taws xob, cov khoom siv hluav taws xob tswj hluav taws xob thiab lwm yam circuits rau kev txwv tam sim no thiab tam sim no sib koom ua piv txwv thiab kev sim. . Lub hauv paus ntsiab lus muaj nyob rau hauv daim duab hauv qab no. Qhov ntsuas hluav taws xob tau siv los ntawm cov cuab yeej, tswj circuits, thiab lwm yam.
