Multimeter Test Methods rau General -Lub Hom Phiaj Lub Teeb-Emitting Diodes
Lub teeb emitting diode (LED) yog ib hom ntawm lub teeb emitting ntaus ntawv uas ncaj qha txhaj tam sim no. Nws yog qhov tshwm sim ntawm emission ntawm photons thaum stimulated electrons nyob rau hauv ib tug semiconductor siv lead ua rov qab los ntawm ib tug siab zog theem mus rau ib tug tsawg zog theem, uas yog feem ntau hu ua spontaneous emission hloov.
Thaum qhov kev tsis ncaj ncees rau pem hauv ntej yog siv rau PN kev sib tshuam ntawm LED, cov neeg nqa khoom tsawg thiab cov neeg nqa khoom feem ntau (electrons thiab qhov) rov ua dua thiab tawm lub teeb Nws yog ib qho tsim nyog sau cia tias rau ntau cov khoom ntawm cov qib siab zog, txhua qhov spontaneously emits ib kem ntawm lub teeb nthwv dej nrog ib tug angular frequency {0}, tab sis tsis muaj ntau zaus, kev sib raug zoo ntawm lub teeb nthwv dej nyob rau hauv txhua kem, thiab lawv muaj peev xwm muaj sib txawv polarization cov lus qhia; Thiab lub teeb emissions los ntawm txhua qhov particle propagates nyob rau hauv tag nrho cov kev taw qhia, cov txheej txheem no yog hu ua spontaneous emission, thiab nws emission wavelength yuav qhia tau los ntawm cov nram qab no kab zauv:
λ(μm)=1.2396/Eg(eV)
Lub teeb emitting diodes (LEDs) feem ntau yog ua los ntawm cov ntaub ntawv xws li gallium arsenide thiab gallium phosphide. Nws muaj PN hlws ris sab hauv thiab kuj muaj unidirectional conductivity, tab sis lub teeb - emitting diode emits lub teeb thaum coj mus rau pem hauv ntej kev taw qhia, thiab lub brightness ntawm lub teeb nce nrog rau qhov nce ntawm cov conduction tam sim no. Cov xim ntawm lub teeb muaj feem xyuam nrog lub wavelength.
Ntsuas nrog multimeter hauv R × 10K ntau yam
Siv lub pointer multimeter nrog 10k Ω ntau tuaj yeem txiav txim siab qhov zoo ntawm lub teeb -emitting diode. Nquag, qhov kev tiv thaiv pem hauv ntej ntawm lub diode nyob ntawm kaum mus rau 200k Ω, thiab qhov rov qab ua haujlwm yog ∞. Yog tias qhov kev tiv thaiv pem hauv ntej yog 0 lossis ∞, thiab qhov rov qab ua haujlwm tsawg heev lossis 0, nws yog qhov ua rau puas tsuaj. Txoj kev tshawb pom no tsis tuaj yeem soj ntsuam lub cev tawm ntawm lub teeb ntawm lub teeb -emitting raj, raws li 10k Ω ntau yam tsis tuaj yeem muab qhov loj rau pem hauv ntej rau LED.
Siv ob lub multimeter los ntsuas ua ke
Yog tias muaj ob lub pointer multimeters (pom zoo rau tib tus qauv), nws tuaj yeem kuaj xyuas lub teeb pom kev zoo ntawm LED. Txuas lub "+" davhlau ya nyob twg ntawm ib lub multimeter mus rau qhov "{2}}" davhlau ya nyob twg ntawm lwm lub multimeter siv ib tug hlau. Cov cwj mem ntxiv "{4}}" txuas nrog rau tus ncej zoo (P cheeb tsam) ntawm qhov ntsuas LED, thiab cov cwj mem "+" ntxiv yog txuas nrog tus ncej tsis zoo (N cheeb tsam) ntawm qhov ntsuas LED. Ob lub multimeters yog teem rau X 10 Ω ntau. Raws li ib txwm muaj, nws tuaj yeem teeb pom kev zoo li qub tom qab txuas nrog. Yog tias qhov ci ntsa iab qis heev lossis txawm tsis tawm lub teeb, ob qho tib si multimeters tuaj yeem teeb tsa rau * 1 Ω. Yog tias nws tseem tsaus heev lossis txawm tsis tawm lub teeb, nws qhia tau tias LED muaj kev ua haujlwm tsis zoo lossis puas. Nws yuav tsum tau muab sau tseg tias ob lub multimeters yuav tsum tsis txhob muab tso rau ntawm x 1 Ω thaum pib ntawm qhov ntsuas kom tsis txhob muaj ntau dhau tam sim no thiab kev puas tsuaj rau lub teeb -emitting diode.
Kev ntsuas cov khoom siv hluav taws xob sab nraud
Cov yam ntxwv ntawm photoelectric thiab hluav taws xob ntawm lub teeb -emitting diodes tuaj yeem ntsuas tau yog siv lub 3V voltage regulator lossis ob series txuas nrog roj teeb qhuav thiab multimeter (xws li pointer lossis digital). Txhawm rau ua tiav qhov no, lub voj voog tuaj yeem txuas tau raws li qhia hauv daim duab 10. Yog tias qhov ntsuas VF nyob nruab nrab ntawm 1.4 thiab 3V thiab qhov luminous brightness yog qhov qub, nws tuaj yeem qhia tau tias qhov luminescence yog qhov qub. Yog tias VF=0 lossis VF ≈ 3V ntsuas thiab tsis muaj lub teeb tawm, nws qhia tau tias lub teeb - emitting raj tawg.
