LED backlighting yog siv los txhim kho qhov pom kev hauv maub ntawm cov zaub thiab cov tswj tuav. Kev hloov ntawm cov LEDs nyob rau hauv chav tsev tom qab raug xaiv tau nyob ntawm lawv cov xim thiab qhov muab cov voltage.
Cov Lus Qhia
Kauj ruam 1
Lub ntsuas hluav taws xob poob thoob plaws ntawm LED ntawm qhov khiav hauj lwm tam sim no raug txiav txim siab hauv kev sim. Nqa lub zog fais fab uas muaj hom kev ruaj khov tsis tsuas rau hluav taws xob, tab sis kuj tseem ceeb tam sim no. Maj mam nce qhov tam sim no los ntawm xoom mus ua haujlwm (nws feem ntau yog sib npaug rau 20 mA). Tom qab ntawd txuas tus voltmeter mus rau lub diode thiab ntsuas qhov voltage poob hla nws. Koj tuaj yeem ua yam tsis muaj qhov no, paub tias qhov voltage poob hla lub diode yog inversely proportional rau hluav taws xob hluav taws xob. Rau infrared (700 nm), nws yog txog 1.8 V, thiab rau violet (400 nm) nws tuaj yeem ncav cuag 3.6 V. Rau lub diode dawb, qhov voltage poob yog tib yam li rau ib qho xiav, vim nws yog raws xiav emitting siv lead ua.
Kauj ruam 2
Yuav kom ntseeg tau tias lub resistors dissipate raws li me ntsis hwj chim li sai tau, muab ntau LEDs li sai tau rau muab muab voltage nyob rau hauv lub daisy saw. Rau qhov no, qhov sib xyaw ntawm qhov hluav taws xob hla cov diodes yuav tsum yog ob txog peb qhov hluav taws xob tsawg dua li qhov muab hluav taws xob. Xam cov nqi no los ntawm qhov muab hluav taws xob, koj tau txais lub tshuab hluav taws xob thoob plaws ntawm txoj kev xa tawm kom tsis txhob poob:
Ures = Upit-Udiode * n, qhov twg Ures yog qhov yuav tsum tau tso hluav taws xob thoob plaws hauv lub resistor; V, Usup - muab voltage; V, Udiode - voltage poob thoob ib diode; B, n yog tus lej ntawm diodes txuas nrog hauv kab, pcs.
Kauj ruam 3
Xaiv qhov tsis kam ntawm lub tshuab hluav taws xob tiv thaiv kom thiaj li ntawm qhov hluav taws xob uas poob thoob nws, tam sim no sib luag rau cov kev khiav hauj lwm tam sim no ntws los ntawm nws. Txhawm rau ua qhov no, txhais tag nrho cov ntaub ntawv thawj zaug rau hauv SI system (piv txwv li 20 mA = 0.02 A) thiab hloov lawv hauv qhov qauv:
R = Ures / I, qhov twg R yog qhov yuav tsum ua haujlwm ntawm qhov ntsuas phom; Ohm, Ures - voltage poob hla lub resistor; V, Kuv - kev khiav hauj lwm tam sim no ntawm LED saw, A.
Kauj ruam 4
Txuas hauv series, soj ntsuam qhov polarity, qhov yuav tsum muaj ntawm LEDs thiab ib qho damping resistor. Npaj ntau li ntawm cov saw hlau no raws li yuav tsum tau ua. Txuas lawv rau hauv parallel, tseem hwm lub polarity. Xam cov tam sim no siv los ntawm chav tsev backlight los ntawm lub zog hluav taws xob siv tus qauv:
Yam Khoom = Icir * N, qhov twg Qhov No yog qhov tam sim no tag nrho; A, Ichain - kev khiav haujlwm tam sim no ntawm ib txoj saw; A, N - tus naj npawb ntawm cov saw hlau, pcs.
Qhov tam sim no uas lub zog muab hluav taws xob tsim yuav tsum yog tsawg kawg 1.5 ntawm suav ib qho.
Kauj ruam 5
Xam lub zog siv los ntawm chav tsev backlight:
P = Usup * Nws tagnrho, qhov twg P - lub zog siv; W, Usup - muab voltage; V, Itot - tag nrho tam sim no.
Tau coj cov kev ua tau zoo ntawm chav tsev fais fab sib npaug sib npaug rau 0.7, faib qhov tshwm sim los ntawm tus xov tooj no, thiab koj yuav tau txais cov kwv yees hluav taws xob tau siv thaum lub tuam txhab backlight ua haujlwm los ntawm cov khoom siv loj (tsis suav nrog lwm cov neeg siv txuas nrog).
