Vim li cas LEDs kub thaum ua haujlwm?
There are three main series of high-power LEDs. The first type is the most commonly used high-power lamp beads that imitate lumens, but the most inconvenient part of this kind of lamp beads is that they can only be pasted by hand and cannot be mounted on a placement machine. It cannot pass through the reflow oven, so it can only be soldered manually or on the heating table. The second is Cree's SMD series. The lamp beads are small and the SMD is very convenient. However, because of its small size, the heat generation of the chip is required to be small. Chip requirements are high.
Mainly, Cree is doing (or using Cree's chips), and the price is relatively high. The third one is Samsung's 5630 (5730), which is between high power and low power, generally only 0.5W can be used , it is more convenient for patch, but it is not convenient to use lens, so many lamps with opaque cover use it, and another one is integrated lamp beads, which depends on the number and size of chips.
Siab zog LED
Siab -lub zog LED ua haujlwm kub taub hau yog vim li cas:
Nyob rau pem hauv ntej voltage ntawm LED, cov electrons tau txais lub zog los ntawm qhov hluav taws xob. Tsav los ntawm hluav taws xob teb, lawv kov yeej hluav taws xob ntawm PN kev sib tshuam thiab kev hloov pauv ntawm thaj av N mus rau thaj tsam P. Cov electrons recombine nrog lub qhov nyob rau hauv cheeb tsam P. Txij li thaum cov hluav taws xob dawb ntws mus rau thaj tsam P muaj lub zog ntau dua li cov hluav taws xob valence hauv thaj av P, cov hluav taws xob rov qab mus rau qis - lub zog lub zog thaum lub sij hawm recombination, thiab lub zog tshaj tawm hauv daim ntawv ntawm photons.
Nyob rau hauv txoj kev nyob rau hauv lub diode, electrons yuav siv lub hwj chim vim muaj cov kuj. Lub hwj chim noj ua raws li cov cai ntawm cov khoom siv hluav taws xob: P=I2 R=I2 (RN ntxiv rau RP) ntxiv rau IVTH qhov twg: RN yog qhov tsis kam ntawm N cheeb tsam VTH yog qhov tig {{ 4}} ntawm qhov hluav taws xob ntawm PN hlws ris RP yog lub tshav kub uas tsim los ntawm lub zog siv los ntawm cov tsis kam ntawm P cheeb tsam Rau: Q=Pt qhov twg: t yog lub sij hawm thaum lub diode energized.
Nyob rau hauv qhov tseeb, LED tseem yog ib tug semiconductor diode. Yog li ntawd, thaum lub LED ua hauj lwm nyob rau hauv lub tom ntej kev taw qhia, nws cov txheej txheem ua hauj lwm raws li cov lus piav qhia saum toj no. Lub zog hluav taws xob nws siv yog: P LED=U LED I LED Nyob rau hauv cov mis: U LED yog lub zog pem hauv ntej hla lub teeb ci LED Kuv LED yog tam sim no ntws los ntawm LED, thiab cov hluav taws xob siv hluav taws xob hloov dua siab tshiab mus rau hauv tshav kub thiab tso tawm: Q= P LED t qhov twg: t yog lub hwj chim- raws sij hawm.
Qhov tseeb, lub zog tso tawm los ntawm cov hluav taws xob thaum lawv rov sib txuas nrog lub qhov hauv cheeb tsam P tsis yog muab ncaj qha los ntawm lub zog sab nraud, tab sis vim tias cov hluav taws xob hauv cheeb tsam N muaj lub zog ntau dua li thaj tsam P thaum tsis muaj sab nraud. hluav taws xob teb. Lub valence electron zog theem siab dua Eg. Thaum nws mus txog thaj tsam P thiab rov sib txuas nrog lub qhov los ua valence electron ntawm thaj av P, nws yuav tso tawm ntau lub zog. Qhov loj ntawm Eg yog txiav txim los ntawm cov khoom siv nws tus kheej thiab tsis muaj dab tsi ua nrog rau sab nraud hluav taws xob. Cov nyhuv ntawm lub zog sab nraud ntawm lub tshuab hluav taws xob tsuas yog thawb nws kom txav mus rau hauv kev taw qhia thiab kov yeej cov txiaj ntsig ntawm PN kev sib tshuam.
