Siv LM3914 Dot/Bar Display Driver IC: 5 Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:27

Txawm hais tias LM3914 yog cov khoom lag luam nrov ntawm lub xyoo pua 20th, nws nyob thiab tseem yog neeg nyiam heev. Nws muab txoj hauv kev yooj yim los tso saib cov theem hluav taws xob tawm ncaj qha siv ib lossis ntau pawg ntawm kaum LEDs nrog qhov tsawg kawg ntawm kev fuss.

Koj tuaj yeem xaj LM3914s hauv pob ntawm tsib, kaum thiab 100 los ntawm PMD Txoj Kev nrog xa dawb, thoob ntiaj teb.

Nrog ntau yam sab nrauv lossis cov khoom siv hluav taws xob cov LEDs no tuaj yeem sawv cev rau txhua hom ntaub ntawv, lossis tsuas yog ntsais muag rau koj kev lom zem. Peb yuav dhau los ntawm ob peb qhov piv txwv piv txwv uas koj tuaj yeem siv hauv koj tus kheej cov phiaj xwm thiab vam tias yuav muab tswv yim rau koj rau yav tom ntej. Keeb kwm los ntawm National Semiconductor, LM391X series tam sim no tau ua los ntawm Texas Instruments.

Kauj ruam 1: Pib

Koj yuav xav tau daim ntawv LM3914, yog li thov rub tawm qhov ntawd thiab khaws nws ua qhov kev siv. Yog li - rov qab mus rau qhov pib. LM3914 tswj kaum LEDs. Nws tswj hwm qhov tam sim no dhau los ntawm LEDs nrog kev siv tsuas yog ib tus tiv thaiv, thiab LEDs tuaj yeem tshwm sim hauv kab kab lossis ib qho 'teev' thaum siv. LM3914 muaj kaum-theem faib hluav taws xob, txhua theem thaum mus txog yuav pom teeb pom kev sib xws LED (thiab cov hauv qab nws hauv qib ntsuas hom).

Cia peb xav txog qhov yooj yim tshaj plaws ntawm cov piv txwv (los ntawm nplooj ntawv ob ntawm cov ntaub ntawv) - voltmeter nrog thaj tsam ntawm 0 ~ 5V. Txoj kev tsheb nqaj hlau Vled kuj tseem txuas rau lub zog hluav taws xob hauv peb qhov piv txwv. Tus pin 9 tswj hwm qhov bar/dot zaub hom - nrog nws txuas nrog tus pin 3 lub LEDs yuav ua haujlwm nyob rau hauv hom kab teeb, tso nws qhib rau hom hom.

2.2uF lub tshuab hluav taws xob xav tau tsuas yog thaum "coj mus rau cov khoom siv LED yog 6" lossis ntev dua ". Peb tau teeb tsa lub voj voog saum toj no, thiab tsim 0 ~ 5V DC qhov chaw ntawm 10kΩ potentiometer nrog lub ntsuas hluav taws xob los qhia qhov hluav taws xob - hauv cov vis dis aus hauv qab no koj tuaj yeem pom cov txiaj ntsig ntawm qhov kev ua haujlwm no hauv ob qho tib si teev thiab kab duab hom.

Kauj Ruam 2: Kho kom haum rau Upper Range thiab LED Tam Sim No

Zoo uas yog qhov txaus siab, txawm li cas los xij yog tias koj xav tau qhov sib txawv siv hluav taws xob? Qhov ntawd yog koj xav kom koj cov zaub muaj ntau yam 0 ~ 3 V DC? Thiab koj tswj hwm qhov ntws tam sim no los ntawm txhua LED li cas? Nrog lej thiab resistors. Xav txog cov qauv hauv qab no hauv daim duab.

Raws li koj tuaj yeem pom LED tam sim no (Iled) yog qhov yooj yim, peb tus piv txwv yog 12.5/1210 uas tau xa rov qab 10.3 mA - thiab hauv lub neej tiag tiag 12.7 mA (kev tiv thaiv kev tiv thaiv yuav cuam tshuam rau tus nqi ntawm kev suav). Tawm qhov hluav taws xob - piv txwv li peb yuav tua rau 3 V meter, thiab khaws tib yam tam sim no rau LEDs. Qhov no xav tau kev daws teeb meem rau R2 hauv kab zauv saum toj no, uas tshwm sim nrog R2 = -R1 + 0.8R1V.

Hloov qhov tseem ceeb -R2 = -1210 + 0.8 x 1210 x 3 muab tus nqi ntawm 1694Ω rau R2. Tsis yog txhua tus yuav muaj E48 tus tiv thaiv ntau, yog li sim thiab tau txais qee yam ze li sai tau. Peb pom 1.8 kΩ rau R2 thiab qhia qhov tshwm sim hauv cov vis dis aus hauv qab no.

Koj tuaj yeem tau muaj qhov ntsuas loj dua qhov txiaj ntsig, tab sis cov khoom siv hluav taws xob tsis pub ntau tshaj 25 V yuav xav tau sib npaug lossis ntau dua tus nqi ntawd. Piv txwv li Yog tias koj xav tau 0 ~ 10 V zaub, qhov hluav taws xob yuav tsum yog> = 10V DC.

Kauj Ruam 3: Tsim Kev Cai Ncaj Ncees

Tam sim no peb yuav saib yuav ua li cas thiaj tsim tau qhov txwv qis qis, yog li koj tuaj yeem muaj cov lus qhia uas (piv txwv li) tuaj yeem khwv tau los ntawm tus lej tsis xoom zoo. Piv txwv li, koj xav kom pom qib ntawm 3 thiab 5V DC. Los ntawm ntu yav dhau los, koj paub yuav teeb lub siab tshaj plaws li cas, thiab teeb tsa qhov txwv qis dua yog yooj yim - tsuas yog siv qhov qis dua rau tus pin 4 (Rlo).

Koj tuaj yeem tau txais qhov no los ntawm kev siv cov khoom sib cais lossis lwm yam khoom siv nrog ib qho GND. Thaum tsim cov hluav taws xob zoo li no, nco ntsoov tias kev ua siab ntev ntawm cov tiv thaiv siv hauv qhov faib hluav taws xob yuav cuam tshuam rau qhov raug. Qee tus neeg tuaj yeem xav kom haum trimpots, uas tom qab ua kom sib haum tuaj yeem teeb tsa mus tas li nrog cov kua nplaum. Thaum kawg, kom nyeem ntau ntxiv ntawm cov ncauj lus no - rub tawm thiab tshuaj xyuas daim ntawv thov TI.

Kauj Ruam 4: Txuas Ntau LM3914s

Ob lossis ntau LM3914s tuaj yeem txuas ua ke txhawm rau nce cov lej LEDs siv los tso saib cov qib dhau ntawm qhov nthuav dav. Cov xov hluav taws xob zoo ib yam li siv ob chav ywj pheej, tshwj tsis yog REFout (tus pin 7) los ntawm thawj LM3914 tau pub rau REFlo (tus pin 4) ntawm LM3914 thib ob - uas nws REFout tau teeb tsa raws li xav tau rau qhov txwv ntau. Xav txog cov piv txwv hauv qab no schematic uas tau muab lub ntiaj teb qhov tseeb ntawm 0 ~ 3.8V DC.

20 ~ 22kΩ resistor xav tau yog tias koj siv hom kev teev (saib "Dot hom nqa" hauv nplooj kaum ntawm cov ntaub ntawv). Tsiv mus, qhov Circuit Court saum toj no tshwm sim nrog cov vis dis aus hauv qab no.

Kauj Ruam 5: Qhov Twg Los Ntawm No?

Tam sim no koj tuaj yeem pom qhov sawv cev ntawm txhua yam qis qis rau ntau lub hom phiaj. Muaj ntau qhov piv txwv txuas thiab sau cia hauv LM3914 cov ntaub ntawv, yog li nyeem thiab nkag mus tob rau hauv kev ua haujlwm ntawm LM3914.

Tsis tas li ntawd Dave Jones los ntawm eevblog.com tau ua yeeb yaj kiab zoo whcih piav qhia txog kev siv LM3914.

Xaus

Cov ntawv tshaj tawm no tau coj tuaj rau koj los ntawm pmdway.com - txhua yam rau cov kws tsim khoom thiab cov khoom siv hluav taws xob, nrog kev xa khoom dawb thoob ntiaj teb.