Loj npaum li cas cov kuj ntawm LED？
Lub teeb tsom xa cov diodes (LED) yog ua los ntawm cov khoom gallium, arsenic, phosphorus, nitrogen thiab lwm yam ntaub ntawv. Lawv yog ib hom ntawm semiconductor. Lawv muaj unidirectional conductivity thiab tuaj yeem hloov hluav taws xob hluav taws xob rau lub zog hluav taws xob thaum ntxiv rau pem hauv ntej voltage. Loj npaum li cas cov kuj ntawm LED？
Qhov tseeb, muaj ob hom kev tiv thaiv ntawm LED: ib qho yog rau pem hauv ntej tsis kam, lwm qhov yog rov qab tsis kam.
Forward tsis kam: Thaum voltage tau thov rau LED, qhov tam sim no ntws mus rau pem hauv ntej, thiab tus nqi tsis kam ntawm lub diode yog kaum rau 200 k_, uas tsuas zoo li xaim. Cov ua hauj yog nyob ntawm dab tsi cov khoom nws yog ua los ntawm, xws li cov teeb roj LED heev, thiab qhov tsis kam yog kwv yees li kaum ntawm ohms mus rau ntau pua ntawm ohms.
Cov thim rov qab tsis kam: Thaum voltage siv rau LED nyob rau hauv kev coj rov qab, qhov dej ntws tam sim no hauv txoj kev rov qab, thiab qhov kev tawm tsam yuav tsis kawg. Vim li cas? Qhov no vim hais tias cov LED yog tsim los ntawm PN hlws ris thiab muaj kev coj ua tsis zoo, ib yam li diodes zoo tib yam.
Thaum ntsuas qhov ntsuas tau zoo (qhov zoo sib txuas P, kev sib txuas tsis zoo N), hluav taws xob hluav taws xob tsim los ntawm ntsuas lub ntsuas hluav taws xob yuav tsum loj dua qhov hluav taws xob sib txuas. Rau cov raj silicon, qhov ntsuas hluav taws xob feem ntau siab dua li 0.7V, tom qab ntawd qhov ntsuas qhov me me tuaj yeem ntsuas.
Thaum rov qab ntsuas qhov ntsuas (zoo N, P tsis zoo), hluav taws xob hluav taws xob tsim los ntawm qhov ntsuas qhov ntsuas hluav taws xob yog nyob rau tib qho kev sib tw nrog qhov chaw txuas hluav taws xob. Lub qhov hluav taws xob kom zoo dua yuav tiv thaiv txhua qhov ntws ntawm cov khoom siv hluav taws xob, thiab tom qab ntawd qhov cuam tshuam loj dua yuav ntsuas.
Thaum kawg, cia peb xaus tias qhov tsis kam ntawm lub teeb ci hluav taws xob diodes tuaj yeem muab faib ua ob qho xwm txheej: ib qho yog kev tiv thaiv rau pem hauv ntej, lwm qhov yog rov qab tsis kam, kev tawm tsam yav tom ntej yog kwv yees li kaum rau 200 kΩ, thiab qhov thim rov qab tsis muaj qhov kawg.
