Vim li cas lub teeb zoo LED hlaws tsis teeb thaum ntsuas nrog multimeter?
LED teeb hlaws kuj tseem hu ua lub teeb-emitting diodes, uas yog ib qho ntawm cov diodes. Thaum siv digital multimeter los ntsuas LED teeb hlaws, nws feem ntau ntsuas nrog nws cov iav diode. Tus cwj mem liab kuaj yog txuas nrog tus ncej zoo ntawm LED teeb hlaws, thiab tus cwj mem ntsuas dub txuas nrog rau tus ncej tsis zoo ntawm LED teeb hlaws. Kev txiav txim los ntawm kev pom qhov pom qhov ci (me ntsis ci) ntawm LED teeb hlaws. Qee lub sij hawm, vim li cas cov teeb pom kev zoo LED hlaws tsis teeb thaum ntsuas nrog lub ntsuas ntsuas? Muaj ob qho laj thawj.
1. Qhov tsis muaj qhov hluav taws xob ntawm lub diode iav ntawm cov digital multimeter feem ntau yog li 2.8V ± 0.2V.
Nco qab tias peb feem ntau siv lub multimeter beep los nrhiav qhov tsis raug, xws li ntsuas qhov txuas ntxiv ntawm cov xov hlau, thiab lwm yam. Thaum ob lub ntsiab lus ntsuas txuas nrog, lub multimeter yuav beep. Lub beep hom ntsuas tus nqi kuj ntawm ob lub ntsiab lus, thiab 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 yog switched los ntawm ib tug khawm. Qhov tseeb, lub hauv paus ntsiab lus ntsuas yog qhov zoo sib xws, ib qho yog tus nqi tshwj xeeb voltage, thiab lwm qhov yog buzzer.
Lub hauv paus ntsiab lus ntawm lub diode iav ntawm lub multimeter yog tias muaj qhov tsis tu ncua tam sim no 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 cov diodes zoo tib yam, cov hlau kuaj liab txuas nrog rau tus ncej zoo ntawm lub diode, thiab cov hlau kuaj dub txuas nrog cov ncej tsis zoo. Tus nqi hluav taws xob tso tawm los ntawm multimeter yog qhov voltage poob ntawm lub diode. Cov khoom siv silicon diode feem ntau yog hais txog {{0}}.7V, thiab cov khoom siv germanium diode yog li 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, lub teeb-emitting diodes siv los ua lub teeb qhia lub zog yog xim liab, ntsuab thiab daj, thiab lawv cov hluav taws xob hluav taws xob poob yog li 1.8V ~ 2.2V.
Lub conduction voltage poob ntawm dawb thiab xiav teeb 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 diode thiab kev ua haujlwm voltage ntawm LED teeb hlaws. Qhov ntsuas hluav taws xob siab tshaj plaws ntawm multimeter diode yog li 2.8V ± 0.2V. Thaum lub ntsuas hluav taws xob ua haujlwm ntawm lub teeb ci LED nyob rau hauv qhov ntsuas hluav taws xob, qhov ua haujlwm tam sim no ntawm 1mA Nws yuav ua rau lub teeb pom kev zoo me ntsis, tab sis thaum ntsuas LED teeb hlaws muaj qhov ua haujlwm siab, xws li saum toj no 3V, LED teeb. hlaws yuav tsis dimly lit vim qhov tsis txaus cov zis voltage ntawm diode thaiv ntawm lub multimeter. Qhov no yog vim li cas LED teeb hlaws yog qhov qub, tab sis nws tsis teeb thaum ntsuas nrog multimeter.
