LCD backlight control with BJT

-

hi all,

i'm new arduino , research online found out pin on lcd screen used backlight control.

i want control backlight depending on values obtained ldr. have managed ldr working , reading values well. furthermore, researching found cannot directly connect arduino pin on lcd. need bjt.

could please guide me how can decided bjt can used purpose? possible suggestion bjt?

many thanks


 

 

1. have check (datasheet of lcd), max current flowing through backlight. determine how current bjt has handle (there operating range).
backlight current assumption: 50ma. (recommendation: don't go max! (mightbe on 120ma !).

2. voltage won't issue if power 5 .. 12v.

3. have decide, if go npn or pnp, depending on how switch transistor. if go high activate backlight, npn bjt do.

4. there dozens if not hundreds of npn's out, match requirements.
taking above said consideration, go e.g. bc547 or equivalent.

(max ec voltage = 45v, max current = 100ma).

look @ link, find more information.


Arduino Forum > Using Arduino > General Electronics > LCD backlight control with BJT


arduino

Comments

Post a Comment

Popular posts from this blog

Valutazione Template - Joomla! Forum - community, help and support

-
salve, prima di installare joomla, vorrei porvi tre semplici domande: 1) l'ultima versione in italiano di joomla, supporta questo template prodotto da gavik? loro scrivono che non è un semplice template, ma una vera e propria suite, ma vorrei una vostra opinione. qui sono descritte le funzioni della suite. 2) per sfruttare gli elementi che si vedono nella pagina, ad esempio quello in alto sinistra dove scorrono le notizie, occorre installare qualche componente aggiuntivo? 3) futuri upgrade alla piattaforma joomla, potranno inficiare il funzionamento o la compatibilità del template? vi ringrazio anticipatamente della disponibilità. 1) non vedo nulla di particolare se non una miriade di posizioni per blocchi 2) è un modulo se non sbaglio pagamento, ma adesso non ricordo bene 3) no. ti ricordo che devi installare joomla  1.0.12 Board index Joomla! International Language Support International Zone Italian Forum ...
Read more

SD Datastring Convention

-
i wondering if there preferred convention appending data logged?  see standard sd example uses: code: [select] void loop() {   // make string assembling data log:   string datastring = "";   // read 3 sensors , append string:   (int analogpin = 0; analogpin < 3; analogpin++) {     int sensor = analogread(analogpin);     datastring += string(sensor);     if (analogpin < 2) {       datastring += ",";     }   } creating string called datastring, , appending it, have seen in forums string not liked.  around this, code data logging looks this: code: [select] void sdupdate() {   datetime = rtc.now();   unsigned int hour = now.hour();   unsigned int minute = now.minute();   unsigned int second = now.second();   char datastring[100] = "";   char char_current_pay[15] = "";   char char_overall_pay[15] = ""; ...
Read more

First use of Arduino Uno : avrdude error on Blink uploading

-
hi all, i bought arduino (or should genuino) starter kit. first test , failing. i have follow religiously first pages , when trying upload blink sketch, uploading fails avrdude error : avrdude: stk500_recv(): programmer not responding. as suggested in other posts, have tried 1) switch latest hourly build of arduino ide 2) switch previous stable version of arduino ide (1.6.09) 3) change usb cable 1 know working fine 4) make same steps on computer (unfortunatelly, of them macos running on macos 10.11.6, not interesting test) 5) press reset before upload, interesting thing : tx led never flashes the full log attached. idea of why happening ? to save people having download log, it's sync error, resp=0x00 every time: code: [select] avrdude: stk500_recv(): programmer not responding avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00 avrdude: stk500_recv(): programmer not responding and he's running 1.6.11 hourly avrdude 6.0.1. ...
Read more