Guest Posted October 24, 2016 Share Posted October 24, 2016 (edited) am nevoie sa imi spuna cine se pricepe mai bine la citit DS-uri.. IRF4905 deschide "full" la -4V sau doar la -10V ? Edited October 24, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
UDAR Posted October 24, 2016 Share Posted October 24, 2016 Vgs(th) , dup? cum Quote Link to comment Share on other sites More sharing options...
Guest Posted October 24, 2016 Share Posted October 24, 2016 (edited) un raspuns complet. totusi, IRF4905 este un HEXFET, adica nu e "logic level" ? shit. noroc ca am de unde sa-i dau tensiune ca i-am comandat... Edited October 24, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
UDAR Posted October 24, 2016 Share Posted October 24, 2016 HEXFET e o tehnologie . Poate fi sau nu Quote Link to comment Share on other sites More sharing options...
Guest Posted October 24, 2016 Share Posted October 24, 2016 (edited) e ok schema asa ?... PS: nu am folosit niciodoata P-MOSFET , foloseam High Side Switch, insa vreau sa reduc costul la montaj.. Edited October 24, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
Guest Posted October 24, 2016 Share Posted October 24, 2016 sunt inversate in schema Drain cu Source, din repezeala, dar ma refer in special la div. rezistiv pe intrarea lui IRF4905 Quote Link to comment Share on other sites More sharing options...
Mircea Posted October 24, 2016 Share Posted October 24, 2016 @radu, si eu multumesc pentru explicatii.AG, "frumoasa" schema, am mai zis ca esti lene? (). R3 si R2 sunt inutile, zic eu. R4 poate fi si mai mic. Quote Link to comment Share on other sites More sharing options...
UDAR Posted October 25, 2016 Share Posted October 25, 2016 Schema este func?ional? ( ?i cu observa?iile lui @thunderer eventual ) dar tranzistorul ?la este absolut subdimensionat acolo - dac? v?d eu bine c? sarcina este 200m? adic? 75A! Quote Link to comment Share on other sites More sharing options...
nel65 Posted October 25, 2016 Share Posted October 25, 2016 Nu trebuie inversate D-S intre ele?Asa cum e acum ,e in conductie continua prin dioda interna. Quote Link to comment Share on other sites More sharing options...
Guest Posted October 25, 2016 Share Posted October 25, 2016 (edited) AG, "frumoasa" schema, am mai zis ca esti lene? ( ). R3 si R2 sunt inutile, zic eu. R4 poate fi si mai mic. da ce naiba sunt pictor ? nu ma pricep la facut scheme inteligibile...nu e vorba de lene ) (mai mult prostie) @nel65, am spus deja ca sunt inversate. @radu, in schema reala am 3 in paralel pe radiator comun. daca il scot pe R2, o sa fie antena intr-un mediu cu bruiaje maxime...ramane. despre R3 si R4...nu stiu...pentru ca de-asta am si postat schema..R3 ma gandeam la 4.7K cu 10K ca sa rezulte cei -10V din 15V. Poate fi si peste 15V la un moment dat...ca nu e stabilizata tensiunea pe ramura aia. Edited October 25, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
Mircea Posted October 25, 2016 Share Posted October 25, 2016 Pictore, vorbeai de redus costul. D-aia ziceam de rezistente. Vgs este +/-20V, pana pe la 18V e safe fara rezistente. In plus, iti doresti O comanda ferma, adica catre 0V pe poarta.Oricum, cate vreme Q1 e blocat vei avea cei 15V in poarta. Cu divizorul tau cobori tensiunea undeva la 5V. De ce sa nu cobori la zero? Daca Q1 poate intra accidental in conductie, atunci pastreaza R2. PS: N-am vrut sa te supar numindu-te lenes, te-am tachinat un pic. Spor la treaba. Quote Link to comment Share on other sites More sharing options...
Guest Posted October 25, 2016 Share Posted October 25, 2016 (edited) maine vin, si-i pun un pic pe breadboard, inainte sa fac pcb-ul. o sa vad atunci. nu m-am suparat ca m-ai numit lenes, doar ca m-am intristat...fiind adevarat ce spui... dar e ok, sunt prea obisnuit in stilul asta haotic personal, ca sa mai ma corectez...asa ca, m-as bucura daca nu m-ai mai "certa" pe tema asta .. L.E: totusi, esti sigur ca divizorul ala de 4.7K & 10K, coboara la -5V din -18V ?... pentru ca mie-mi iasa -10.204V ... Edited October 25, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
Mircea Posted October 25, 2016 Share Posted October 25, 2016 Pai 15V dupa divizorul ala sunt 5V. Adica -10V fata de Vd=15V.Poti da detalii despre aplicatia ta?Scuze pentru dojeneala. Quote Link to comment Share on other sites More sharing options...
Guest Posted October 25, 2016 Share Posted October 25, 2016 (edited) da. e un charger auto, dar vreau niste functii de genul quick charge de asta am nevoie de curentii aia mari. am notat +5, acolo fiind iesirea unui uC.. Edited October 25, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
Guest Posted October 27, 2016 Share Posted October 27, 2016 (edited) eu tot nu inteleg un lucru...poate ma lumineaza cineva.. spre rusinea mea nu inteleg o banalitate. din ce am inteles eu, dupa cum spune thunderer , prin Q1 trec doar cei 5V. astfel ca divizorul e degeaba , ba mai mult chiar incurca. eu insa vad altfel, poate gresit, de-asta va rog sa ma corectati. eu vad ca prin Q1, "curg" atat tensiunea de 5V spre masa, cat si cea de 15V spre masa(din Q4), ceea ce inseamna ca divizorul format din R3&R4 este necesar... cum este de fapt ?...ceva nu inteleg...eu sau... Edited October 27, 2016 by Guest Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.