Vim li cas cov digital multimeter fais fab tuag thaum siv buzzer iav?
Nws tsis tuaj yeem txiav txim siab tias lub roj teeb khiav qis. Thaum siv lub buzzer hom, lub buzzer yog ib qho inductive load, thiab qhov tam sim no voltage kuj yuav siab, uas yuav rub down lub roj teeb tsawg thiab ua rau lub ntsiab nti kaw ncaj qha vim voltage tsis txaus.
Yog tias lub roj teeb tseem zoo li qub tom qab hloov pauv, nws tuaj yeem tshwm sim los ntawm luv luv Circuit Court lossis to hauv lub buzzer lossis lwm yam tsav tsheb. Tsis tas yuav tinker ntxiv lawm. Multimeter nqi me ntsis thiab siv sij hawm ntau dua.
Los yog tsuas yog hloov lub buzzer thiab sim nws tawm. Yog tsis ua hauj lwm, cia li yuav ib tug tshiab.
Feem ntau muaj ob qhov xwm txheej thaum lub digital multimeter tau kaw thaum siv hom buzzer. Ib qho yog tias lub roj teeb ntawm lub multimeter yog qub, thiab thaum lub buzzer hom nrog kev siv hluav taws xob siab ua haujlwm, lub roj teeb hluav taws xob poob qis, ua rau lub multimeter yuav kaw tau; Lwm qhov xwm txheej yog tias muaj kev ua haujlwm tsis zoo nyob rau hauv hom buzzer, qhov twg tam sim no thaum lub sijhawm ua haujlwm siab, ua rau muaj qhov txo qis hauv roj teeb voltage thiab ua rau lub multimeter kaw. Hauv qab no, peb yuav muab cov ncauj lus qhia ntxaws ntxaws txog txoj hauv kev ua haujlwm thiab kev daws teeb meem ntawm buzzer hom Circuit Court ntawm digital multimeter
Schematic daim duab ntawm Circuit Court rau buzzer hom ntawm ib tug multimeter digital.
Lub CD4011 nyob rau hauv daim duab yog CMOS low-power quad 2 input NAND rooj vag, uas txuas nrog ntawm no los tsim ib lub zog tswj lub suab oscillator. Thaum kuaj lub Circuit Court rau / tawm nrog lub buzzer hom, yog tias qhov kev tiv thaiv ntawm qhov ntsuas qhov ntsuas Rx tsawg dua lossis sib npaug li 70 Ω (qee qhov kuj tau teeb tsa rau lwm qhov tseem ceeb), tus pin ① ntawm LM324 tawm qib siab, ua rau lub zog tswj lub suab oscillator muaj li ntawm CD4011 ua haujlwm. Lub piezoelectric ceramic nti emits lub suab nrov, thiab tib lub sijhawm, LED qhov taw qhia teeb kuj pib teeb.
Kev ua hauj lwm tam sim no ntawm lwm qib ntawm cov digital multimeter feem ntau yog nyob rau hauv 10mA, thaum lub buzzer theem siv ib tug kuj loj npaum li cas ntawm hluav taws xob vim lub piezoelectric ceramic vuas thiab qhov taw qhia teeb. Yog hais tias lub roj teeb ntawm lub multimeter yog qub, nws yuav ua rau ib tug tseem ceeb txo nyob rau hauv lub roj teeb voltage, ua rau lub multimeter kaw.
Tsis tas li ntawd, yog hais tias lub CMOS rooj vag Circuit Court CD4011 los yog piezoelectric ceramic nti ntawm lub buzzer iav malfunctions, nws yuav ua rau kom lub zog noj ntawm tag nrho cov buzzer iav, uas yuav ua rau lub multimeter yuav cia li kaw. Tus sau yav dhau los tau kho qhov tsis raug nrog kev siv hluav taws xob siab hauv cov chaw buzzer, feem ntau nrog CD4011 lossis piezoelectric ceramic chips. Thaum muaj qhov luv luv luv ntawm ob qho kawg ntawm daim ntawv piezoelectric ceramic, nws yuav ua rau lub buzzer tsim suab tsawg thiab ua rau muaj zog siv zog.
