Environmental Audio Loudness Meter: 5 Kauj Ruam

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

Kuv qhov project yog lub ntsuas suab qhia los ntawm LEDs. Nws ua rau siv lub tshuab electret microphone, op amp, thiab LM3914 LED Driver IC. Yuav siv nws li cas ib puag ncig ib puag ncig lub sensor yog, ntau lub LEDs tau qhib los ntawm LM3914. Nws yog qhov haujlwm yooj yim thiab txaus siab uas zoo rau cov neeg tuaj tshiab rau hluav taws xob.

Cov ntaub ntawv:

· Creadboard (Lee tus #10516)

· Jumpers LOS YOG (Wire Stripper THIAB Breadboard Wire) (Lee's #10325 + ntau yam)

· 10 × Thru qhov LEDs (Lee's #549 + ntau yam)

· Electret Microphone (Lee tus #2272)

· Kev Ua Haujlwm Amplifier (Lee's #7292 / #7293)

· LM3914 (Lee tus #7034)

· 1 μF Capacitor (Lee tus #8962 / #82)

· 3 × 2.2 kΩ resistors (Lee's #9223 / #9548)

· 2 × 1 kΩ resistors (Lee tus #9190)

· 330 kΩ resistor (Lee tus #9427)

· Potentiometer THIAB Ntsia Hlau (Lee tus #71044 + ntau yam)

· 2 × AA × 3 roj teeb pob (Lee's #21079)

Kauj ruam 1: Txuas Txuas Lub Microphone

Txuas lub electret microphone siv cov dhia rau hauv av. Kuj txuas lwm tus pin raws li qhia hauv kab lus. Thov xa mus rau daim ntawv teev npe kom paub seb tus pin yog leej twg. Lub capacitor lead tsis txuas ncaj qha rau lub mic tuaj yeem xav tias yog cov khoom nyoos sensor tso tawm. Txawm li cas los xij qhov ntsuas hluav taws xob no yuav muaj DC kev tsis ncaj ncees. Txhawm rau kho qhov no, peb tuaj yeem rub cov zis tawm rau hauv av nrog 1 kΩ resistor. Qhov no tsim qhov uas paub tias yog lim siab dhau hauv qhov no txhais tau hais tias DC ib feem ntawm lub teeb liab tsis dhau los ntawm cov zis tab sis <15 mV ncov rau ncov AC teeb liab ua. Thaum lub mic tau teeb tsa kom raug, thov txheeb xyuas tias qhov hluav taws xob tso tawm (AC) tshwm sim kom raug.

Kauj Ruam 2: Txhim Kho Lub Circuit Court

Kuv siv ob qhov sib cais 4.5 V DC, tab sis yog tias koj twb muaj qee yam zoo sib xws uas yuav ua haujlwm zoo ib yam. Qhov no xav tau rau AC mic teeb liab kom viav vias tag nrho txawm tias thaum ua kom nrov nrov. Cov xov hlau liab thiab dub yuav tsum txuas nrog txoj kab kom thiaj li muaj +Vcc, -Vcc, thiab cov tsheb hauv av.

Kauj Ruam 3: Kev nthuav tawm ntawm Mic Output

Raws li yog qhov xwm txheej nrog cov hloov pauv feem ntau, lub teeb liab tsawg dhau los yuav pab tau rau peb. AC cov cim tuaj yeem ua kom nrov nrog cov ua haujlwm siab, hloov pauv, lossis hloov pauv. Txawm li cas los xij kuv pom op amps qhov yooj yim tshaj plaws los ua haujlwm nrog yog li peb yuav tsom mus rau op amps. Tsuas yog ib qho khoom siv ob leeg op amp xav tau (Kuv siv TL084 tab sis koj tuaj yeem siv qhov twg koj xav tau). Txhua op amp ICs yuav tsum muaj tsawg kawg 5 tus pin uas yog Vs+ (qhov zoo muab qhov hluav taws xob), Vs- (qhov tsis zoo muab hluav taws xob), V+ (tsis hloov pauv tswv yim), V- (inverting input), thiab Vo (tso zis). Muaj ntau qhov kev xav tom qab op amps tab sis qhov tseem ceeb rau peb yog tias Vo tsis tuaj yeem mus dhau V + thiab V- (qhov tseeb, qhov tseeb ntau yog dab tsi lub npe hu ua + Vsat thiab -Vsat), cov lus tawm tswv yim kos tsis muaj tam sim no (theoretically tsis xyaum), thiab cov inverting thiab inverting inputs tau khaws cia ntawm tib qhov hluav taws xob thaum op amp nyob hauv cov lus tsis zoo (Vo txuas nrog V-).

Saib schematic rau kev sib txuas. Peb kev teeb tsa yog dab tsi paub tias yog lub suab tsis hloov pauv lub ntsiab lus uas tau nce yog qhov zoo. Qhov tau txais txiaj ntsig zoo yog Av = Vo / Vi. Rau lub suab tsis hloov pauv, Av = Vo / Vi = 1 + Rf / Ri. Peb tab tom siv tus tiv thaiv qhov tseem ceeb ntawm 1 kΩ thiab 330 kΩ kom ua tiav qhov nce ntawm 331. Thaum txhua yam txuas nrog, yuav tsum muaj lub teeb liab ntshiab ntawm AC teeb liab ntawm Vo.

Kauj Ruam 4: Txuas Txuas LM3914

LM3914 yog qhov kev xaiv zoo tshaj plaws rau peb los tsim lub ntsuas ntsuas sib piv LED yam tsis siv lub microcontroller thiab ADC. Nws yog LED tsav IC Peb tsis xav paub txhua yam tshwj xeeb ntawm nws sab hauv, tab sis peb yuav tsum paub siv nws li cas. Nws muaj 10 qhov tseem ceeb ua haujlwm qis qis uas yog cov hauv paus tam sim no. IC no tseem muaj V- thiab V+ uas yog cov khoom siv hluav taws xob. RLO thiab RHI yog thaj tsam rau lub teeb liab mus nruab nrab. Rau peb lub hom phiaj RLO yog hauv av thiab RHI tau hloov kho rau siv lub lauj kaub nruab nrab ntawm Vref thiab hauv av. RLO yuav tsum tsis pub tshaj Vref. Hom xaiv tus pin yuav tsum tau ua kom siab kom peb tau txais tag nrho cov nyhuv bar nrog LEDs. Ib qho xim LED tuaj yeem siv tau, txawm li cas los xij kuv siv ntsuab, txiv kab ntxwv, liab, thiab xiav LEDs. Xa mus rau schematic rau txhua qhov kev sib txuas. Nrog koj zoo siab! Koj ua tiav.

Kauj ruam 5: Sau ntawv

Lub voltmeter yuav yog cov cuab yeej muaj txiaj ntsig zoo rau txoj haujlwm no rau kev daws teeb meem. Lub oscilloscope tseem muaj txiaj ntsig ntau rau txoj haujlwm no txiav txim siab nws cuam tshuam nrog kev ncaj ncees ntawm AC. Txawm hais tias nws tsis tsim nyog rau peb txoj haujlwm, peb tuaj yeem hloov kho Vo los ntawm op amp rau lub teeb liab DC huv rau siv nrog LM3914. Thov xa mus rau cov ntawv teev cov ntaub ntawv rau txhua cov ntaub ntawv ntxiv ntawm electret, op amp, lossis LM3914.