Thaum ntsuas nrog multimeter, vim li cas LED qhov muag teev zoo tsis teeb?
LED teeb hlaws kuj tseem hu ua lub teeb-emitting diodes, uas yog ib hom diode. Thaum siv digital multimeter los ntsuas LED teeb hlaws, qhov teeb tsa diode feem ntau yog siv rau kev ntsuas. Cov hlau kuaj liab txuas nrog rau qhov zoo electrode ntawm LED teeb hlaws, thiab cov hlau kuaj dub txuas nrog qhov tsis zoo electrode ntawm LED teeb hlaws. Txiav txim los ntawm kev soj ntsuam qhov ci (me ntsis ci) ntawm LED teeb hlaws nrog qhov muag liab qab. Qee lub sij hawm, vim li cas cov teeb pom kev zoo LED hlaws tsis teeb thaum ntsuas nrog lub ntsuas ntsuas? Muaj ob lub laj thawj tseem ceeb.
1. Qhov tsis muaj-load voltage ntawm diode txoj hauj lwm ntawm ib tug digital multimeter feem ntau yog hais txog 2.8V ±0.2V.
Nco qab tias peb feem ntau siv lub buzzer teeb tsa ntawm multimeter los nrhiav qhov tsis raug, xws li ntsuas qhov txuas ntxiv ntawm cov xov hlau. Thaum ob lub ntsiab lus xeem txuas nrog, lub multimeter yuav buzz. Lub beep hom ntsuas tus nqi kuj ntawm ob lub ntsiab lus. Lub multimeter yuav beep thaum tus nqi kuj tsawg dua li ntawm 70Ω. Nyob rau hauv ntau lub multimeters, lub diode iav thiab lub buzzer iav yog ua ke nyob rau hauv tib lub iav thiab tuaj yeem hloov tau los ntawm nias lub pob. Qhov tseeb, lub hauv paus ntsiab lus ntsuas zoo ib yam. Ib qho nqi hluav taws xob tiag tiag thiab lwm qhov yog buzzer.
Lub hauv paus ntsiab lus ntawm multimeter's diode iav yog tias muaj qhov tam sim no nyob rau hauv. Qhov tsis muaj-load tso zis voltage ntawm qhov tam sim no qhov chaw yog li 2.8V. Tus nqi voltage ntawm ntau hom multimeters txawv me ntsis, feem ntau ntawm 2.6V thiab 3V. Qhov chaw tam sim no qhov tso zis tam sim no yog li 1mA,
Thaum ntsuas ib qho diode zoo tib yam, cov hlau lead kuaj liab txuas nrog qhov zoo electrode ntawm diode, thiab cov hlau kuaj dub txuas nrog qhov tsis zoo electrode. Tus nqi hluav taws xob tso tawm los ntawm multimeter yog qhov voltage poob ntawm lub diode. Silicon khoom diodes feem ntau yog hais txog {{0}}.7V, thiab germanium khoom diodes yog hais txog 0.3V.
2. Lub pem hauv ntej voltage poob ntawm LED teeb hlaws yog hais txog 1.8V ~ 3.5V
Cov xim sib txawv thiab hom LED teeb hlaws muaj qhov sib txawv conduction voltage tee. Feem ntau, cov xim ntawm lub teeb-emitting diodes siv los ua lub teeb pom kev muaj zog yog xim liab, ntsuab thiab daj, thiab lawv cov hluav taws xob conduction poob yog li 1.8V ~ 2.2V.
Lub conduction voltage poob ntawm lub teeb dawb thiab xiav hlaws yog hais txog 2.7V ~ 3.3V. Cov teeb pom kev hauv tsev LED teeb hlaws yog feem ntau dawb LED teeb hlaws, thiab lawv qhov ua haujlwm voltage yog li 3V, 2.8V, 3.3V, 3.5V, thiab lwm yam.
Kev tsom xam: Nkag siab lub hauv paus ntsiab lus ntawm multimeter's diode ntau thiab ua haujlwm voltage ntawm LED teeb hlaws. Nws tuaj yeem pom tias qhov ntsuas qhov siab tshaj plaws ntawm qhov ntsuas qhov ntsuas diode yog li 2.8V ± 0.2V. Thaum lub ntsuas hluav taws xob ua haujlwm ntawm LED teeb hlaws yog nyob rau hauv qhov ntsuas hluav taws xob no, kev khiav hauj lwm tam sim no ntawm 1mA Lub LED yuav ci me ntsis, tab sis thaum ntsuas kev ua hauj lwm voltage ntawm LED teeb hlaws yog qhov siab, xws li saum toj 3V, LED teeb hlaws yuav tsis ci me ntsis vim hais tias lub multimeter diode tso zis voltage tsis txaus. Qhov no yog vim li cas cov hlaws LED teeb pom kev zoo ib txwm muaj, tab sis lawv tsis teeb thaum ntsuas nrog multimeter.
