Pulse Dav Modulated LED Teeb: 8 Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:31

Pulse dav tes taws los piav (PWM) tuaj yeem siv los hloov pauv lub zog, nrawm lossis ci ntawm ntau yam khoom siv. Nrog LEDs, PWM tuaj yeem siv los txo lawv, lossis ua kom lawv ci dua. Kuv yuav siv lawv ua lub teeb taws me me. Ntau LED tuaj yeem tsaus muag los ntawm kev tig nws tawm sai sai, ob peb zaug ib pliag. Los ntawm kev sib txawv ntawm qhov chaw cim qhov sib piv, qhov ci ntsa iab tau hloov pauv. Qhov kev siv yooj yim ntawm PWM qhov system yuav yog lub sijhawm pub zaub mov rau LED thiab tiv thaiv tus tiv thaiv rau hauv av. qhov oscillation. Txhawm rau ntsuas qhov no, koj tuaj yeem siv lub tshuab hluav taws xob teeb tsa los muab lub voos xwmfab, raws li hauv qab no, lossis tsim ib qho Circuit Court los ua rau koj.

Kauj Ruam 1: Relaxation Oscillator

Lub voj voog no yuav tsim cov xwm txheej ib puag ncig nrog lub luag haujlwm ntawm 50%. Ob 10K resistors txuas nrog rau +kev nkag ntawm op -amp muab qhov ntsuas hluav taws xob, thiab R1 thiab C1, txuas nrog -input, tsim lub sijhawm tas li uas tswj hwm qhov zaus, f = 1/{2ln (3) RC}. Tus capacitor C1 tsub thiab tso tawm los ntawm tus tiv thaiv R1, thiab lub sijhawm siv rau qhov kev hloov pauv no tshwm sim yog lub sijhawm ntawm cov nthwv dej.

Kauj Ruam 2: Relaxation Oscillator

Los ntawm kev txheeb xyuas qhov zaus hauv qib 1, R1 tuaj yeem hloov pauv nrog lub zog loj, RP, nrog tus nqi 2R1, thiab ob lub diodes. Qhov kev hloov pauv no yuav tso cai rau lub luag haujlwm hloov pauv, thaum tswj hwm qhov tsis tu ncua. Yog tias muaj qhov yuav tsum tau ua kom raug, tom qab ntawd lub zog ntsuas hluav taws xob tau xaiv yuav tsum nyob ze, tab sis tsis pub ntau tshaj 2R1, thiab kev tiv thaiv kev them nyiaj sib npaug sib npaug R1-RP/2. Cov kev daws teeb meem yog siv ob lub resistors nyob rau hauv series nrog ob diodes, kom muab lub sijhawm ua haujlwm ruaj khov, thiab tau npaj ua ntej.

Kauj Ruam 3: Kev Tso Tawm Oscillator Tso Tawm

Lub moos teeb liab tuaj yeem txuas ncaj qha rau ib qho LED, tab sis qhov no yuav tsis tso cai rau LED los ntawm lwm qhov laj thawj. Nws tuaj yeem hloov tau yooj yim los pub cov zis no mus rau lub hauv paus ntawm transistor, thiab tom qab ntawd siv lub transistor los hloov LED rau thiab tawm. Qhov muaj peev xwm faib tawm ntawm cov tswv yim ntawm transistor yog txhawm rau txo qhov tso tawm ntawm kev so oscillator, txij li thaum nws tsis nyob hauv lub xeev, nws tseem yuav tso tawm 2v. Qhov no yuav tsum tau txo qis qis dua 0.7v txhawm rau kom tsis txhob hloov ntawm lub transistor, txwv tsis pub LED yuav nyob tas li thiab ua noj.

Kauj Ruam 4: Ua kom pom kev ci ntsa iab

Lwm daim ntawv thov muaj txiaj ntsig ntawm PWM nrog LED yog tias LED tuaj yeem muaj qhov loj dua li ib txwm tam sim no dhau los ntawm nws ua rau nws ci dua. Feem ntau qhov tam sim no tam sim no yuav rhuav tshem LED, tab sis txij li lub LED tsuas yog nyob rau ib feem ntawm lub sijhawm, lub zog nruab nrab muab los ntawm LED yog nyob rau hauv kev ua siab ntev. Qhov txwv ntawm qhov tam sim no tau piav qhia ntawm cov chaw tsim khoom cov ntaub ntawv rau LED, txheeb xyuas raws li lub plawv dhia tam sim no. Kuj tseem muaj ntau cov ntsiab lus hais txog qhov dav dav ntawm mem tes thiab txoj haujlwm ua haujlwm. Siv lub LED dawb ua piv txwv, cov lus qhia tshwj xeeb hauv qab no tau muab raws li: Forward Current = 30mAPulse Forward Current = 150mAPulse Dav = <10msDuty Cycle = <1: 10 Siv cov lus qhia dav dav thiab lub luag haujlwm, cov kev so kom txaus tuaj yeem suav nrog T = 2ln (2) RC Kev suav 10nF lub tshuab hluav taws xob tau siv, thiab xav TON = 10ms, thiab TOFF = 1ms, cov lej hauv qab no tuaj yeem ua tau, thiab tom qab ntawv kos duab kos duab.

Kauj Ruam 5: Ua kom muaj zog ntxiv

Lwm qhov yuav tsum tau ua kom pom kev ci ntsa iab yog kom nce qhov ntws tam sim no los ntawm LED. Qhov no yog qhov ncaj ncaj rau pem hauv ntej. Piv txwv tias yog 5v lub tswv yim muab rau LED, thiab los ntawm cov ntaub ntawv cov ntaub ntawv tus qauv ntsuas hluav taws xob ntawm LED yog 3.6v. Kev tiv thaiv tiv thaiv tuaj yeem suav los ntawm kev rho tawm LED qhov hluav taws xob los ntawm qhov muab hluav taws xob, thiab tom qab ntawd faib qhov no los ntawm qhov tam sim no. R = (VS - VLED) / (iMAX) R = (5 - 3.6) / 0.15R = 1.4 / 0.15R = 9.3 = 10RIt txawm li cas los xij tias cov khoom siv hluav taws xob LED yuav tsis tuaj yeem muab qhov txaus tam sim no ntawm 100mA, txawm tias nws yog lub sijhawm luv luv. Tej zaum nws yuav tsim nyog siv lub zog LED los ntawm lub transistor, muaj peev xwm tswj tau los ntawm lwm lub transistor hauv koob kuj muaj peev xwm nqa tau tam sim no. me me. Muaj 0.7v poob rau ob qho tib si transistors, thiab 3.6v hla LED, tag nrho 5v, thiab tsis muaj dab tsi rau kev tiv thaiv tiv thaiv. Txawm li cas los xij, rau lub teeb, kev tswj hwm tuaj yeem tso rau ntawm lub zog hluav taws xob rau hauv Circuit. VR = 9 - (3.6 + 0.7) VR = 4.7vR = 4.7 / 0.15R = 31 = 33R

Kauj Ruam 6: Kawg Circuit Court

Hauv qab no yog daim duab kab lus kawg. Thaum ua tiav, yuav hloov mus rau lub zog hluav taws xob, thiab lwm tsib LED-resistor khub yuav muab tso ua ke nrog cov khub uas twb muaj lawm.

Kauj Ruam 7: Xeem Circuit

Nov yog tib qho LED version ntawm Circuit. Tsis tshwj xeeb tshaj yog huv, tab sis nws yog tus qauv, thiab ua raws daim duab qhia chaw los ntawm kauj ruam 7. Koj tseem tuaj yeem pom los ntawm cov khoom siv hluav taws xob uas tsuas yog 24mA raug kos, piv nrog 30mA yog tias LED txuas nrog ib txwm muaj. Los ntawm daim duab thib peb uas muaj ob lub LEDs, nws pom tias ob qho tib si LEDs yog qhov ci tib yam. Txawm li cas los sai heev, cov tsav ncaj qha LED ua kom sov sai sai muab qhov laj thawj zoo rau PWM.

Kauj Ruam 8: Tiav Teeb

Kev xa cov Circuit mus rau veroboard yog qhov nyuaj, tshwj xeeb tshaj yog ua kom lub zog oscillator so kom nws thiaj haum rau hauv rooj plaub. Qhov tseem ceeb los tshuaj xyuas yog tias tsis muaj xov hlau hla, lossis xoob txaus kom hla. Ntxiv lwm 5 LEDs, hloov pauv nrog cov roj teeb txuas thiab tom qab tso cov no rau hauv rooj plaub yog ncaj dua-txuas mus. Txuas cov khoom siv hluav taws xob mus rau lub roj teeb txuas los ntsuas lub Circuit Court, qhov nruab nrab nyeem tam sim no yog kwv yees li 85mA. Qhov no yog qhov me dua 180mA (6*30mA) uas yuav tsum tau siv lub tshuab ncaj qha. Kuv tsis tau nkag mus rau qhov nthuav dav nrog kev hloov pauv lub Circuit Court los ntawm lub khob cij, mus rau veroboard raws li kuv tau tsom mus rau siab rau txoj kev xav tom qab txoj haujlwm no, tshaj qhov nws tshwj xeeb. Txawm li cas los xij raws li cov lus qhia dav dav, koj yuav tsum ntsuas lub Circuit Court thiab ua kom nws ua haujlwm ntawm lub khob cij, tom qab ntawd hloov cov khoom mus rau veroboard, pib nrog cov khoom me me. Yog tias koj muaj peev xwm thiab nrawm ntawm kev sib txuas, koj tuaj yeem tuaj yeem ruaj ntseg txuas lub nti ncaj qha mus rau lub rooj tsavxwm, txwv tsis pub koj yuav tsum siv tus tuav ntiv tes.