Kev Txiav Txim Siab Sib Piv Analog LED Fader Nrog Txoj Kab Ntsig Brightness: 6 Cov Kauj Ruam (nrog Duab)

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:28

Feem ntau ntawm cov hluav taws xob kom ploj/dim ib lub LED yog cov siv hluav taws xob siv PWM tso tawm ntawm lub microcontroller. Qhov ci ntawm LED yog tswj los ntawm kev hloov pauv lub luag haujlwm ntawm PWM teeb liab. Tsis ntev koj pom tias thaum hloov pauv hloov lub luag haujlwm, LED ci tsis hloov pauv. Qhov ci ntsa iab yuav ua raws qhov nkhaus logarithmic, txhais tau tias qhov hloov pauv nrawm thaum nce lub luag haujlwm los ntawm 0 kom hais 70% thiab hloov pauv qeeb heev thaum nce lub voj voog ua haujlwm los ntawm hais 70% rau 100%. pom thaum siv qhov tam sim no tsis tu ncua thiab nce tam sim no tawm fe los ntawm kev them tus nqi hluav taws xob nrog qhov tam sim no.

Hauv cov lus qhia no kuv yuav sim qhia koj yuav ua li cas koj tuaj yeem ua qhov sib piv LED fader uas muaj qhov hloov pauv qhov ci uas zoo li yog kab rau tib neeg qhov muag. Qhov no ua rau muaj txiaj ntsig zoo tawm ntawm cov kab tawm.

Kauj Ruam 1: Txoj Kev Xav Tom Qab Lub Circuit Court

Hauv daim duab, koj tuaj yeem pom tias qhov pom kev pom ntawm LED muaj lub logarithmic nkhaus vim yog txoj cai Weber-Fechner, hais tias tib neeg qhov muag, ib yam li lwm qhov kev nkag siab, muaj qhov nkhaus logarithmic. Thaum LED nyuam qhuav pib "ua" qhov pom kev pom tau nce nrawm nrog nce ntxiv tam sim no. Tab sis ib zaug "ua", qhov pom kev ci ntsa iab nce qeeb nrog kev nce tam sim no. Yog li peb yuav tsum xa qhov hloov pauv tam sim no (saib daim duab) los ntawm LED yog li tib neeg lub qhov muag (nrog kev nkag siab logarithmic) pom qhov kev hloov pauv zoo li yog tawm.

Muaj 2 txoj hauv kev los ua qhov no:

• Kaw lub voj kev
• Qhib voj mus kom ze

Kaw lub voj kev:

Thaum ua tib zoo saib ntawm LDR (cadmium sulphide) cov xov tooj ntawm tes, koj yuav pom tias LDR tsis kam raug kos ua kab ncaj nraim ntawm qhov ntsuas logarithmic. Yog li LDR tsis kam hloov logarithmic nrog lub teeb pom kev ntxiv. Ntawm no, logarithmic tsis kam nkhaus ntawm LDR zoo li sib phim rau logarithmic ci pom kev ntawm tib neeg qhov muag zoo nkauj heev. Tias yog vim li cas LDR yog tus neeg sib tw zoo tshaj plaws los qhia tawm qhov pom kev pom ntawm LED. Yog li thaum siv LDR txhawm rau txhawm rau txhawm rau kev nkag siab logarithmic, tib neeg lub qhov muag yuav txaus siab los ntawm qhov zoo sib txawv qhov ci ci sib txawv. LDR los tawm tswv yim thiab tswj lub teeb ci LED, yog li nws ua raws LDR nkhaus. Txoj hauv kev no peb tau txais qhov nthuav dav hloov pauv qhov ci uas pom tias yog kab rau tib neeg qhov muag.

Qhib voj mus kom ze:

Thaum peb tsis xav siv LDR thiab xav kom tau txais qhov hloov pauv qhov ci rau cov fader, peb yuav tsum ua tam sim no los ntawm LED nthuav tawm los them nyiaj rau qhov kev nkag siab qhov pom kev pom ntawm tib neeg qhov muag. Yog li peb xav tau lub Circuit Court uas tsim qhov nthuav dav hloov pauv tam sim no. Qhov no tuaj yeem ua tiav nrog OPAMP's, tab sis kuv pom qhov yooj yim Circuit Court, uas siv daim iav hloov pauv tam sim no, tseem hu ua "squarer" tam sim no vim tias tsim tam sim no ua raws cov kab nkhaus (ib nrab nthuav tawm). Hauv cov lus qhia no, peb ua ke ob qho kaw lub voj thiab qhib lub voj mus kom tau txais qhov hloov pauv fading LED. txhais tau tias ib qho LED ploj hauv thiab tawm thaum lwm qhov LED ploj hauv thiab tawm nrog qhov nkhaus fading rov qab.

Kauj Ruam 2: Schematic1 - Daim Duab Peb Hlis Waveform Generator

Rau peb cov LED fader, peb xav tau qhov hluav taws xob qhov hluav taws xob uas ua kom muaj qhov nce ntxiv thiab txo qhov hluav taws xob. Peb kuj xav kom tuaj yeem hloov pauv qhov ploj hauv thiab ploj mus ib ntus ntawm tus kheej. Rau lub hom phiaj no peb siv lub tshuab hluav taws xob peb tog sib npaug sib npaug uas tau tsim los siv 2 OPAMPs ntawm cov haujlwm qub: LM324. U1A tau teeb tsa raws li schmitt txhais siv cov lus pom zoo thiab U1B tau teeb tsa ua kev sib koom ua ke. Qhov zaus ntawm daim duab peb sab yog txiav txim siab los ntawm C1, P1 thiab R6. Qhov tsis zoo no muab qhov nce tam sim no uas peb xav tau los tsav tam sim no txaus rau hauv LED Circuit. Cov lus tawm tswv yim nyob ib puag ncig U1B raug coj los ntawm qhov tso tawm ntawm qhov tsis, hloov pauv los ntawm OPAMP cov zis. vim OPAMPs tsis nyiam lub peev xwm thauj khoom (xws li C1). R8 tau ntxiv rau qhov tso tawm ntawm OPAMP rau qhov laj thawj ruaj khov, vim tias cov neeg siv emitter, xws li siv hauv qhov tsis (Q1, Q2) kuj tseem tuaj yeem ua rau oscillations thaum tsav los ntawm qhov tsis muaj impedance tso tawm. qhov hluav taws xob ntawm qhov tso tawm ntawm qhov tsis tsim los ntawm Q1 thiab Q2.

Kauj Ruam 3: Schematic2 - Kaw Loop LED Fader Circuit

Txhawm rau qhia qhov ci ntawm LED, LDR tau siv los ua cov lus tawm tswv yim hauv kev kaw lub voj kaw. Vim tias LDR tsis kam tiv lub teeb pom kev yog logarithmic, nws yog tus neeg sib tw tsim nyog los ua txoj haujlwm. Q1 thiab Q2 tsim daim iav tam sim no uas hloov pauv qhov hluav taws xob hluav taws xob ntawm lub voos xwmfab peb tog tsim hluav taws xob mus rau tam sim no ntawm R1, uas yog nyob rau hauv "txhais ceg "ntawm daim iav tam sim no. Tam sim no los ntawm Q1 yog tsom mus rau Q2, yog li tib lub voos xwmfab tam sim no ntws los ntawm Q2. D1 nyob ntawd vim tias cov zis ntawm lub tshuab hluav taws xob daim duab peb sab tsis ua tag nrho viav vias rau xoom, vim tias kuv tsis siv txoj kev tsheb nqaj hlau-rau-tsheb nqaj hlau yooj yim kom tau txais lub hom phiaj dav dav OPAMP hauv lub voos xwmfab peb tog tsim hluav taws xob. Qhov LED txuas nrog Q2, tab sis kuj yog Q3, uas yog ib feem ntawm daim iav tam sim no thib ob. Q3 thiab Q4 tsim daim iav tam sim no. (Saib: Cov tsom iav tam sim no) Lub LDR tau muab tso rau hauv "txhais ceg" ntawm daim iav nrhiav tam sim no, yog li qhov tsis kam ntawm LDR txiav txim siab qhov tam sim no tsim los ntawm daim iav no. Qhov ntau lub teeb poob rau ntawm LDR, qis nws qhov kev tiv thaiv thiab siab dua tam sim no los ntawm Q4 yuav yog. Tam sim no los ntawm Q4 yog tsom mus rau Q3, uas txuas nrog Q2. Yog li tam sim no peb yuav tsum xav txog cov dej tam sim no thiab tsis nyob hauv qhov hluav taws xob ntxiv lawm. I3 yog qhov tam sim no dhau los ntawm LED thiab yog qhov tshwm sim ntawm cov kab duab plaub peb tog tam sim no I1 rho tawm logarithmic LDR tam sim no I2, uas yog qhov nthuav tawm tam sim no. Vim tias qhov nthuav tawm tam sim no tau tsav los ntawm LED, qhov pom kev pom kev yuav hloov pauv ib txoj hauv kev, uas muaj qhov ua kom zoo dua qub/ua kom pom kev zoo dua li tsuas yog siv cov kab tawm tam sim no los ntawm LED.), uas sawv cev rau tam sim no los ntawm LED.

Kauj Ruam 4: Schematic3 - Qhib Loop LED Fader Circuit Siv Tam Sim No Squarer

Vim tias LED/LDR kev sib txuas ua ke tsis yog cov txheej txheem txheej txheem, kuv tau tshawb nrhiav lwm txoj hauv kev los tsim qhov nthuav tawm lossis nthuav dav tam sim no los ntawm LED hauv kev qhib lub teeb tsa. Qhov tshwm sim yog lub voj voos qhib qhia hauv cov kauj ruam no. Q1 thiab Q2 tsim ib qho kev sib tw tam sim no uas yog raws li daim iav tam sim no. R1 hloov cov duab hluav taws xob peb tog tso tawm, uas yog thawj zaug faib siv P1, mus rau qhov tam sim no, ntws los ntawm Q1. Tab sis tus emitter ntawm Q1 tsis txuas nrog hauv av ntawm tus tiv thaiv, tab sis ntawm 2 diodes. 2 diodes yuav muaj qhov cuam tshuam ntawm qhov tam sim no mus txog Q1. Qhov tam sim no tau tsom mus rau Q2, yog li I2 muaj tib lub nkhaus nkhaus. Q3 thiab Q4 tsim qhov txuas mus tas li tam sim no. Cov LED txuas nrog rau qhov tam sim no tsis tu ncua tab sis kuj tseem rau cov iav tam sim no poob qis Q1 thiab Q2. Yog li tam sim no dhau los ntawm LED yog qhov tshwm sim ntawm qhov tam sim no I1 rho tawm qhov tam sim no I2, uas yog ib nrab-nthuav tawm tam sim no I3 Qhov kev nthuav tawm tam sim no los ntawm LED yuav ua rau muaj qhov zoo tawm ntawm qhov pom kev pom ntawm LED. P1 yuav tsum tau txiav kom LED cia li tawm thaum ploj mus. Qhov duab oscilloscope qhia qhov ntsuas hluav taws xob hla R2 (= 180E), uas sawv cev rau tam sim no I2, uas tau rho tawm los ntawm qhov tam sim no I1.

Kauj Ruam 5: Schematic4 - Hloov LED Fader los ntawm Kev Sib Txuas Ob Leeg

Vim tias LED tam sim no nyob rau hauv lub voj voos qhib tau hloov pauv thaum piv rau LED tam sim no hauv kev kaw lub voj voos, peb tuaj yeem sib txuas ob qho kev sib txuas los tsim ib qho kev hloov pauv LED fader uas ib qho LED ploj mus thaum lwm qhov ploj thiab tawm mus.

Kauj Ruam 6: Tsim Circuit Court

• Kuv tsuas yog tsim lub Circuit Court ntawm daim ntawv qhia zaub mov, yog li kuv tsis muaj PCB txheej txheem rau hauv Circuit Court
• Siv cov LEDs ua haujlwm tau zoo vim tias cov no muaj kev sib zog ntau dua ntawm tib yam tam sim no dua li cov LEDs qub
• Txhawm rau ua LDR/LED ua ke, muab lub LDR (saib daim duab) thiab LED ntsej muag rau lub ntsej muag hauv lub raj nqaim (saib daim duab).
• Lub Circuit Court tau tsim los rau kev muab hluav taws xob los ntawm +9V txog +12V.