Dab tsi tuaj yeem ua rau tus neeg kho tshuab multimeter qhov tsis kam ua kom tawg?
Yog hais tias qhov kev tiv thaiv ntau yam ntawm cov tshuab multimeter, piv txwv li lub pointer multimeter, puas thiab lwm yam tuaj yeem kuaj tau ib txwm, nws qhia tau tias lub taub hau meter yuav tsum tsis txhob cuam tshuam. Raws li lub hauv paus ntsiab lus ntawm kev ntsuam xyuas ntawm lub multimeter qhov kev tiv thaiv ntau yam, nws yog ib qho zoo heev uas qhov tseeb tsis kam ntawm shunt voltage division nyob rau hauv lub resistance range yog burnt tawm los yog tus nqi kuj hloov. Qhov feem ntau yuav ua rau muaj kev puas tsuaj rau qhov tsis kam ntawm cov tshuab multimeter yog ntsuas qhov ntsuas hluav taws xob siv qhov kev tiv thaiv ntau yam raws li qhov ntsuas hluav taws xob. Yog li, ua ntej txhua qhov kev xeem, nws yog ib qho tseem ceeb uas yuav tsum tau siv los xyuas seb qhov kev xaiv iav yog qhov tseeb thiab txhim kho tus cwj pwm zoo.
Cov iav tiv thaiv ntawm lub pointer hom multimeter tawg, thiab lwm yam iav siv tau, qhia tias lub taub hau multimeter zoo. Qhov no yog tshwm sim los ntawm kev siv tsis raug. Muaj ob qho laj thawj rau qhov no. Ib qho yog ntsuas cov hlau qhov txhab tiv thaiv ntawm ntau qhov kev tiv thaiv me me hauv AC220V qhov hluav taws xob hluav taws xob tam sim no thaum unplugged nyob rau hauv DC tam sim no ntau yam (tsis hais tus qauv ntawm pointer multimeter, lawv yog tag nrho cov hlau qhov txhab resistors, tag nrho. ua los ntawm tooj liab tsis kam xaim, thiab cov nqi tiv thaiv tsawg heev Piv txwv li, hauv MF-47 qauv, muaj plaub resistors nrog 0.54 Ω 5.4 Ω 54 Ω 540 Ω, feem). Tab sis tus neeg hais lus tau hais tias lub multimeter tsuas muaj teeb meem nrog cov iav tiv thaiv, yog li tsis muaj teeb meem nrog nws tshwm sim hauv cov iav no.
Qhov thib ob yog vim li cas; Rau cov pib siv hluav taws xob thiab hluav taws xob, tom qab siv qhov kev tiv thaiv ntau yam ntawm lub tshuab hluav taws xob los ntsuas cov khoom siv lossis kuaj cov khoom siv hluav taws xob, yog tias lub tshuab hluav taws xob tsis tau teeb tsa rau AC 500V ntau thiab tom qab ntawd sim rau AC lub zog hauv 220V AC kab lossis lub qhov (socket). Muaj ntau ntau tus qauv thiab cov chaw tsim khoom siv ntau hom pointer multimeters. Cov feem ntau siv thiab feem ntau yog cov qub-fashioned 500 qauv thiab MF-47 multimeter ua nyob rau hauv Nanjing.
① MF {{0}}} multimeter muaj DC tam sim no ntau yam (DCA), nrog rau tag nrho tsib qhov kev siv ntau yam thiab 5A siab tam sim no nthuav qhov (socket), xws li 0 ~ {{5} }.05mA ~ 0.5mA ~ 5mA -50mA ~ 500mA.
② Nws muaj yim lub zog siv rau qhov hluav taws xob ncaj qha tam sim no (DCV) thiab lub qhov (socket) nthuav dav uas tuaj yeem ntsuas DC2500V. 0 ~ 0.25V ~ 1V ~ 2.5V ~ 10V ~ 50V ~ 250V ~ 500V ~ 1000V ~ 2500V.
③ Muaj rau qib AC voltage (ACV), 0 ~ 10V ~ 50V ~ 250V ~ 500V ~ 2500.
④ Nws muaj tsib theem ntawm DC tsis kam (Ω). R × 1 Ω R × 10 Ω R × 100 Ω Rx1K Ω R × 10K Ω, thiab txoj kev buzzer rau kev ntsuas (thaum cov kab hluav taws xob tiv thaiv yog nyob nruab nrab ntawm 3-10 Ω, lub buzzer yuav tawm suab ceeb toom). Vim muaj qhov chaw tsawg, kev ua haujlwm xws li transistor DC amplification factor hFE, infrared remote control transmission signal detection, and audio level DB raug tshem tawm.
Ua ntej, thaum ntsuas qhov tsis kam, qhov kev sojntsuam dub tau muab tso rau hauv lub qhov → tus ncej tsis zoo ntawm lub taub hau meter → qhov tsis kam ntawm 20.2 Ω, qhov tsis kam ntawm 220.4 Ω, thiab qhov tsis kam ntawm 2430 Ω, tag nrho cov uas nyob rau hauv parallel nrog lub taub hau meter. Nyob rau lub sijhawm no, cov tshuaj ntsuam liab tau muab tso rau hauv kaum lub qhov (sockets) ntawm lub multimeter thiab dhau los ntawm 1A fuse raj. Tom qab ntawd, 1.5V qhuav roj teeb yog txuas nrog cov resistor thiab dhau los ntawm 20k resistor. Tom qab ntawd, qhov sib txawv potentiometer yog xoom hauv 1.7k resistor ntau. Thaum kawg, 500 Ω resistor yog siv los ntsuas R + ntawm lwm lub taub hau. Thaum kawg, tus ncej zoo ntawm lub taub hau meter yog cim. Thaum koj nkag siab txog lub kaw lus kaw, nws yooj yim los lis. Raws li kev paub ntawm tus kheej, koj tuaj yeem tshawb nrhiav tau yooj yim.
Siv lwm lub multimeter los saib thiab ntsuas cov kev tawm tsam no. Feem ntau, hom kev ua txhaum no tsuas yog hlawv qhov tsis kam ntawm cov iav resistor uas tau rub tawm thaum lub sijhawm. Thiab cov resistors no tsis yog tus qauv muaj nuj nqis, uas tuaj yeem txuas nrog hauv cov khoom siv hluav taws xob nyob ze lossis hloov los ntawm ib feem ntawm tooj liab xov qhwv ib ncig ntawm lub resistor. Cov hlau tooj liab tuaj yeem txiav los ntawm lub qhov txhab hloov pauv potentiometer. Yog hais tias nws yog tus pheej yig dua MF-47 hom nrog SMT, koj tsuas tuaj yeem nug cov chaw tsim khoom kom pab.
Yog hais tias qhov kev tiv thaiv ntau yam ntawm cov tshuab multimeter, piv txwv li lub pointer multimeter, puas thiab lwm yam tuaj yeem kuaj tau ib txwm, nws qhia tau tias lub taub hau meter yuav tsum tsis txhob cuam tshuam. Raws li lub hauv paus ntsiab lus ntawm kev ntsuam xyuas ntawm lub multimeter qhov kev tiv thaiv ntau yam, nws yog ib qho zoo heev uas qhov tseeb tsis kam ntawm shunt voltage division nyob rau hauv lub resistance range yog burnt tawm los yog tus nqi kuj hloov. Qhov feem ntau yuav ua rau muaj kev puas tsuaj rau qhov tsis kam ntawm cov tshuab multimeter yog ntsuas qhov ntsuas hluav taws xob siv qhov kev tiv thaiv ntau yam raws li qhov ntsuas hluav taws xob. Yog li, ua ntej txhua qhov kev xeem, nws yog ib qho tseem ceeb uas yuav tsum tau siv los xyuas seb qhov kev xaiv iav yog qhov tseeb thiab txhim kho tus cwj pwm zoo.
Cov iav tiv thaiv ntawm lub pointer hom multimeter tawg, thiab lwm yam iav siv tau, qhia tias lub taub hau multimeter zoo. Qhov no yog tshwm sim los ntawm kev siv tsis raug. Muaj ob qho laj thawj rau qhov no. Ib qho yog ntsuas cov hlau qhov txhab tiv thaiv ntawm ntau qhov kev tiv thaiv me me hauv AC220V qhov hluav taws xob hluav taws xob tam sim no thaum unplugged nyob rau hauv DC tam sim no ntau yam (tsis hais tus qauv ntawm pointer multimeter, lawv yog tag nrho cov hlau qhov txhab resistors, tag nrho. ua los ntawm tooj liab tsis kam xaim, thiab cov nqi tiv thaiv tsawg heev Piv txwv li, hauv MF-47 qauv, muaj plaub resistors nrog 0.54 Ω 5.4 Ω 54 Ω 540 Ω, feem). Tab sis tus neeg hais lus tau hais tias lub multimeter tsuas muaj teeb meem nrog cov iav tiv thaiv, yog li tsis muaj teeb meem nrog nws tshwm sim hauv cov iav no.
Qhov thib ob yog vim li cas; Rau cov pib siv hluav taws xob thiab hluav taws xob, tom qab siv qhov kev tiv thaiv ntau yam ntawm lub tshuab hluav taws xob los ntsuas cov khoom siv lossis kuaj cov khoom siv hluav taws xob, yog tias lub tshuab hluav taws xob tsis tau teeb tsa rau AC 500V ntau thiab tom qab ntawd sim rau AC lub zog hauv 220V AC kab lossis lub qhov (socket). Muaj ntau ntau tus qauv thiab cov chaw tsim khoom siv ntau hom pointer multimeters. Cov feem ntau siv thiab feem ntau yog cov qub-fashioned 500 qauv thiab MF-47 multimeter ua nyob rau hauv Nanjing.
① MF {{0}}} multimeter muaj DC tam sim no ntau yam (DCA), nrog rau tag nrho tsib qhov kev siv ntau yam thiab 5A siab tam sim no nthuav qhov (socket), xws li 0 ~ {{5} }.05mA ~ 0.5mA ~ 5mA -50mA ~ 500mA.
② Nws muaj yim lub zog siv rau qhov hluav taws xob ncaj qha tam sim no (DCV) thiab lub qhov (socket) nthuav dav uas tuaj yeem ntsuas DC2500V. 0 ~ 0.25V ~ 1V ~ 2.5V ~ 10V ~ 50V ~ 250V ~ 500V ~ 1000V ~ 2500V.
③ Muaj rau qib AC voltage (ACV), 0 ~ 10V ~ 50V ~ 250V ~ 500V ~ 2500.
④ Nws muaj tsib theem ntawm DC tsis kam (Ω). R × 1 Ω R × 10 Ω R × 100 Ω Rx1K Ω R × 10K Ω, thiab txoj kev buzzer rau kev ntsuas (thaum cov kab hluav taws xob tiv thaiv yog nyob nruab nrab ntawm 3-10 Ω, lub buzzer yuav tawm suab ceeb toom). Vim muaj qhov chaw tsawg, kev ua haujlwm xws li transistor DC amplification factor hFE, infrared remote control transmission signal detection, and audio level DB raug tshem tawm.
Ua ntej, thaum ntsuas qhov tsis kam, qhov kev sojntsuam dub tau muab tso rau hauv lub qhov → tus ncej tsis zoo ntawm lub taub hau meter → qhov tsis kam ntawm 20.2 Ω, qhov tsis kam ntawm 220.4 Ω, thiab qhov tsis kam ntawm 2430 Ω, tag nrho cov uas nyob rau hauv parallel nrog lub taub hau meter. Nyob rau lub sijhawm no, cov tshuaj ntsuam liab tau muab tso rau hauv kaum lub qhov (sockets) ntawm lub multimeter thiab dhau los ntawm 1A fuse raj. Tom qab ntawd, 1.5V qhuav roj teeb yog txuas nrog cov resistor thiab dhau los ntawm 20k resistor. Tom qab ntawd, qhov sib txawv potentiometer yog xoom hauv 1.7k resistor ntau. Thaum kawg, 500 Ω resistor yog siv los ntsuas R + ntawm lwm lub taub hau. Thaum kawg, tus ncej zoo ntawm lub taub hau meter yog cim. Thaum koj nkag siab txog lub kaw lus kaw, nws yooj yim los lis. Raws li kev paub ntawm tus kheej, koj tuaj yeem tshawb nrhiav tau yooj yim.
Siv lwm lub multimeter los saib thiab ntsuas cov kev tawm tsam no. Feem ntau, hom kev ua txhaum no tsuas yog hlawv qhov tsis kam ntawm cov iav resistor uas tau rub tawm thaum lub sijhawm. Thiab cov resistors no tsis yog tus qauv muaj nuj nqis, uas tuaj yeem txuas nrog hauv cov khoom siv hluav taws xob nyob ze lossis hloov los ntawm ib feem ntawm tooj liab xov qhwv ib ncig ntawm lub resistor. Cov hlau tooj liab tuaj yeem txiav los ntawm lub qhov txhab hloov pauv potentiometer. Yog hais tias nws yog tus pheej yig dua MF-47 hom nrog SMT, koj tsuas tuaj yeem nug cov chaw tsim khoom kom pab.
