Yooj Yim Autorange Capacitor Tester / Capacitance Meter Nrog Arduino thiab Los Ntawm Tes: 4 Kauj Ruam

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

Nyob zoo!

Txog rau chav physics no koj xav tau:

* lub zog siv nrog 0-12V

* ib lossis ntau lub capacitors

* ib lossis ntau dua them tus tiv thaiv

* ib lub stopwatch

* multimeter rau ntsuas ntsuas hluav taws xob

* tus arduino nano

* 16x2 I²C zaub

* 1 / 4W resistors nrog 220, 10k, 4.7M thiab 1Gohms 1 gohms resistor

* dupont hlau

Kauj Ruam 1: Cov Lus Qhia Txog Cov Capacitors

Cov capacitors ua lub luag haujlwm tseem ceeb hauv cov khoom siv hluav taws xob. Lawv siv los khaws cov nqi, ua cov lim, cov khoom sib txuas, thiab lwm yam. Yog li koj tuaj yeem xyaum ua haujlwm nthuav dav nrog cov capacitors thiab lawv. ua haujlwm tawm Yog tias thawj zaug tsis tau them tus nqi hluav taws xob txuas nrog ntawm tus tiv thaiv rau qhov hluav taws xob, tom qab ntawd cov nqi ntws tsis tu ncua mus rau lub capacitor. Nrog kev nce nqi Q, raws li cov mis Q = C * U (C = capacitance ntawm lub capacitor), qhov hluav taws xob U hla lub capacitor kuj nce ntxiv. Txawm li cas los xij, kev them nqi tam sim no tau poob qis dua thiab ntau dua vim tias lub tshuab hluav taws xob tau them sai sai tau dhau los ua qhov nyuaj dua los sau nrog tus nqi. Qhov voltage U (t) ntawm lub capacitor ua raws cov qauv hauv qab no:

U (t) = U0 * (1-exp (-k * t))

U0 yog qhov hluav taws xob ntawm lub zog siv, t yog lub sijhawm thiab k yog ntsuas ntawm qhov nrawm ntawm cov txheej txheem them nqi. Qhov loj me me k nyob ntawm? Qhov loj dua qhov muaj peev xwm khaws cia (uas yog, lub peev xwm C ntawm lub capacitor), nws qeeb dua nrog cov nqi thiab qeeb qeeb qhov hluav taws xob nce. Qhov loj C, qhov me me k. Qhov tsis kam ntawm lub tshuab hluav taws xob thiab lub zog xa khoom kuj tseem txwv kev thauj khoom. Kev tiv thaiv loj dua R ua rau me me tam sim no kuv thiab yog li tsawg dua tus nqi ib pliag ntws mus rau lub capacitor. Qhov loj R, me dua k. Kev sib raug zoo ntawm k thiab R lossis C yog:

k = 1 / (R * C).

Qhov voltage U (t) ntawm lub capacitor yog li nce raws li cov qauv U (t) = U0 * (1-exp (-t / (R * C))))

Kauj Ruam 2: Kev Ntsuas

Cov tub ntxhais kawm yuav tsum nkag mus rau qhov hluav taws xob U ntawm lub sijhawm t hauv lub rooj thiab tom qab ntawd kos qhov ua haujlwm nthuav tawm. Yog tias qhov hluav taws xob nce nrawm dua, koj yuav tsum nce qhov kev tiv thaiv R. Ntawm qhov tod yog qhov hloov pauv qeeb dhau, txo R.

Yog tias ib tus paub U0, qhov ua haujlwm R thiab qhov hluav taws xob U (t) tom qab lub sijhawm t, tom qab ntawd lub peev xwm C ntawm lub capacitor tuaj yeem suav los ntawm qhov no. Rau qhov no yuav tsum muaj logarithm qhov sib npaug thiab tom qab qee qhov kev hloov pauv peb tau: C = -t / (R * ln (1 - U (t) / U0))

Piv txwv: U0 = 10V, R = 100 kohms, t = 7 vib nas this, U (7 sec) = 3.54V. Tom qab ntawd C ua rau tus nqi C = 160 μF.

Tab sis muaj qhov thib ob, txoj hauv kev yooj yim los txiav txim siab lub peev xwm C. Uas yog, qhov hluav taws xob U (t) tom qab t = R * C yog raws nraim 63.2% ntawm U0.

U (t) = U0 * (1-exp (-R * C / (R * C)) = U0 * (1-exp (-1)) = U0 * 0.632

Qhov no txhais li cas? Cov tub ntxhais kawm yuav tsum txiav txim siab lub sijhawm t tom qab qhov hluav taws xob U (t) yog 63.2% ntawm U0. Tshwj xeeb, rau qhov piv txwv saum toj no, lub sijhawm xav tau tom qab qhov hluav taws xob hla lub capacitor yog 10V * 0.632 = 6.3V. Qhov no yog rooj plaub tom qab 16 vib nas this. Tam sim no tus nqi no tau tso rau hauv qhov sib npaug t = R * C: 16 = 100000 * C. Qhov no ua rau qhov tshwm sim: C = 160 μF.

Kauj ruam 3: Arduino

Qhov kawg ntawm kev tawm dag zog, lub peev xwm tseem tuaj yeem txiav txim siab nrog Arduino. Qhov no xam lub peev xwm C raws nraim li txoj hauv kev ua ntej. Nws them tus nqi hluav taws xob ntawm tus paub resistor R nrog 5V thiab txiav txim siab lub sijhawm tom qab uas qhov hluav taws xob ntawm lub capacitor = 5V * 0.632 = 3.16V. Rau Arduino digital-to-analog converter, 5V sib npaug 1023. Yog li ntawd, koj tsuas yog yuav tsum tau tos kom txog thaum tus nqi ntawm cov khoom siv sib piv yog 1023 * 3.16 / 5 = 647. Nrog lub sijhawm no, lub peev xwm C tuaj yeem suav tau. Yog li cov capacitors nrog cov peev txheej sib txawv tuaj yeem ntsuas tau, 3 qhov sib txawv them nqi tiv thaiv tau siv. Ua ntej, qhov kev tiv thaiv qis tau siv los txiav txim lub sijhawm them nyiaj txog 647. Yog tias qhov no luv dhau, piv txwv li yog tias lub peev xwm ntawm lub capacitor me me dhau, tom ntej yuav tsum tau them ntau dua tiv thaiv. Yog tias qhov no tseem me me 1 Gohms tsis kam ua raws qhov kawg ntawm kev ntsuas. Tus nqi rau C yog tom qab ntawd tso rau ntawm lub vijtsam nrog chav raug (µF, nF lossis pF).

Kauj ruam 4: Cov lus xaus

Cov tub ntxhais kawm kawm paub dab tsi hauv chav no? Koj yuav kawm paub txog cov khoom siv hluav taws xob, lawv lub peev xwm C, cov haujlwm nthuav tawm, logarithm, kev suav ua feem pua thiab Arduino. Kuv xav ntau.

Chav tsev no haum rau cov tub ntxhais kawm hnub nyoog 16-17 xyoo. Koj yuav tsum tau dhau los ntawm qhov ua haujlwm nthuav dav thiab logarithm hauv kev ua lej. Muaj kev lom zem sim nws hauv koj chav kawm thiab Eureka!

Kuv yuav zoo siab heev yog tias koj yuav pov npav rau kuv hauv kev sib tw tshawb fawb hauv chav kawm. Ua tsaug ntau rau qhov no!

Yog tias koj txaus siab rau kuv lwm qhov haujlwm hauv physics, ntawm no yog kuv li youtube channel:

ntau txoj haujlwm physics: