[0:00]Hello students. Aaj se hum basic electronics mein ek naya unit padhne wale hain jo ke hai unit number two bipolar junction transistor and its biasing.
[0:11]So I hope you are ready with your pen and paper, so without wasting much time, let us start this video.
[0:17]Toh aaj ka ye video introductory video hone wala hai transistor ke baare mein.
[0:22]Toh is video mein hum transistor ke use dekhenge, transistor ka matlab samjhenge, uska construction samjhenge, kitne type hote hain, uske kaisi biasing hum kar sakte hain, ye saari baatein dekh lenge.
[0:34]Toh shuru karte hain sabse pehle use se.
[0:38]Toh transistor ki bahut hi jyada varieties of usage hoti hai.
[0:41]Jaise ke hamare mobile phone mein use hota hai, computers, laptops, airplanes, cars, space ship, bahut saari jagah pe transistor ka use hota hai.
[0:51]Ab question aayega ke transistor hota kya hai actual mein?
[0:56]Toh uske liye hum thoda flashback mein jaate hain.
[0:59]Unit number one mein humne semiconductors ke baare mein padha tha.
[1:03]Usme kya dekha tha humne? Ke agar aapke paas ek p-type semiconductor hai aur ek n-type semiconductor hai, dono ko agar aap connect karaate ho, toh ek p-n junction diode ban jaata tha.
[1:13]Iska matlab, abhi hamare paas ek p-n junction diode hai.
[1:17]Aise aap do p-n junction diode ko connect karaoge ek dusre ke saath, toh jo device ban ke aayegi use hum bol denge transistor.
[1:25]Jaise ke yahan pe maine likh ke rakha hai p-n junction diode hai, yahan pe bhi hamara p-n junction diode hai, dono ko apne connect karaya toh usse ek transistor ban gaya jise hum p-n-p transistor bol denge.
[1:38]P-n-p transistor yaani kya? Aisa transistor jisme do p-type jo hamare semiconductor hai uske beech mein do n-type semiconductor humne laga ke rakhe hain.
[1:51]Theek hai? Ya phir aisa bol lo ke aisa transistor jisme do p-type semiconductor, do n-type semiconductor ke beech mein sandwich kiye gaye hain.
[2:01]Ab dusra bhi transistor hai, woh bhi aise hi banayenge.
[2:05]Humne le liya ek p-n junction diode, dusra le liya p-n junction diode, dono ko connect karadiya toh jisse ban gaya hamara n-p-n transistor.
[2:13]N-p-n transistor yaani kya? Aisa transistor jisme do p-type semiconductor, do n-type semiconductor ke beech mein sandwich karke rakhe hain.
[2:23]Ab ye jo dono transistor hai use hum bol denge bipolar junction transistor.
[2:29]Ab by yaani kya? Do pole yaani kya? Do pole hai iske.
[2:36]Ye do pole p-p, ye do pole n-n, bi-polar hogaya aur junction hai, yahan pe n-type ka junction hai, yahan pe p-type ka junction hai, isliye hum ise bol dete hain bi-polar junction transistor.
[2:47]Dusre bhi transistor aate hain jaise ke field effective transistor f-e-t, jo is unit mein hai nahi, toh ye unit mein hum iski baat karne wale nahi hain.
[2:57]Aur is unit mein bhi hum jyadatar n-p-n ki hi baat karenge, kyun? Kyun ki n-p-n ki efficiency hoti hai woh bahut hi jyada hoti hai p-n-p se bhi jyada hoti hai.
[3:07]Ab question aayega ke kyun n-p-n ki efficiency jyada hai toh uska simple answer hai.
[3:13]Hume pata hai n-type semiconductor mein majority charge carriers kaun se hote hain toh electrons hote hain.
[3:19]Aur ye p-type mein kaun se hote hain majority charge carriers? Holes hote hain.
[3:25]Mobility kiski jyada hoti thi? Electrons ki. Yani electrons ki mobility jyada, yani current ka flow jyada.
[3:30]N-p-n mein majority hume electrons jyada milne wale hain isliye iski mobility jyada hogi, isliye current flow jyada hoga, isliye n-p-n ki jo efficiency hai woh p-n-p se jyada hai.
[3:42]Theek hai? Achha, ab question aayega ke ye combination toh dekh liye humne, dusre bhi combination bache hain, kaun se?
[3:47]Jaise ke n-p plus n-p, dusra hai p-n plus p-n. Kya ye combination possible hai?
[3:55]Toh hum bolenge ye combination possible nahi hai.
[3:58]Kya karan hai iska? Simple reason hai ke yahan pe humne kya contact karaya hai p aur n ko ek dusre ke saath connect kiye hain.
[4:04]Aur yahan pe n aur p yaani same p aur n ko connect kiye hain.
[4:08]P kaisa hota hai? Positive. N kaisa hota hai? Negative. P mein holes hote hain, positive. N mein electrons hote hain, negative.
[4:15]Agar dono ko contact mein laaye hum p-n-p-n, toh kya ho jaayega? Diffusion process shuru ho jaayegi.
[4:21]Yani diffusion current banega.
[4:24]Electrons jo hain holes mein diffuse ho jaayenge, toh depletion layer bahut jyada ho jaayega, jiske karan potential barrier badh jaayega, jiske karan current ka flow hoga nahi.
[4:35]Isliye ye transistor possible nahi hai.
[4:39]Ye do transistor possible hain. Toh ye hogayi type ki baat transistor ki.
[4:44]Ab hum dekhenge construction transistor ka. Toh construction yahan pe bana ke rakha hai. Ye kaunsa transistor hai? N-p-n transistor, jise hum bol denge bipolar junction transistor. Theek hai?
[4:54]Yahan pe ye jo p-type semiconductor hai, do n-type semiconductor ke beech mein sandwich karke rakha hai.
[5:00]Ab ye n-type hai, usme se ek terminal nikaal denge hum, jise hum bol denge emitter.
[5:06]P-type mein se ek terminal nikaalenge jise bol denge base.
[5:09]N-type mein se terminal nikaalenge jise bol denge collector.
[5:13]Ab yahan pe kitne terminal hai? Teen terminal hai.
[5:16]Generally jo hamari devices hoti hai usme jo transmission line hoti hai woh char hoti hai.
[5:21]Kaise? Do input ki transmission line aur do output ki transmission line.
[5:26]Yahan pe kitni transmission lines hain? Sirf three transmission lines hain.
[5:30]Ab yahan pe hum, ye jo sare jo hamare jo terminal hai use hum kaise bhi connect kar sakte hain.
[5:35]Jaise ke ye base ko emitter collector se connect kar sakte hain, emitter ko base collector se connect kar sakte hain, collector ko base se bhi connect kar sakte hain, emitter se bhi connect kar sakte hain.
[5:47]Iska matlab ye jo transistor hai bahut jyada flexibility hume deta hai, jiske karan ye transistor bahut hi famous hogaye.
[5:55]Ab yahan pe ye transistor mein thoda aur detail mein dekh lete hain.
[5:59]Jaise ke agar emitter ki baat kare, emitter ki baat, toh uski jo size hoti hai, uski jo size hoti hai woh collector se thodi chhoti hoti hai aur base se bahut badi hoti hai.
[6:09]Base se jyada size hai emitter ki lekin collector se thodi kam hai.
[6:16]Achha, agar ye jo emitter hai uski doping ki baat kare, doping yaani kya? Kuch impurity hum isme mila rahe hain.
[6:21]Toh ye emitter ki impurity sabse jyada hai yaani ki doping sabse jyada ki gayi hoti hai.
[6:27]Doping karna yaani kya? N-type ke andar hum kaun si cheez ka doping karte the? Pentavalent impurity hum mix karte the.
[6:34]Pentavalent impurity mix karne par n-type mein ek electron extra aata tha.
[6:40]Iska matlab kya hua? Jitna jyada doping karoge emitter ka utne jyada number of electron hume milenge.
[6:48]Ab doping kyun jyada karni hai hume emitter ki? Toh uska reason ye hai ke emitter ka function kya hai? To emit the electron, electron ko emit karna.
[6:55]Agar iska doping jyada kiya emitter ka, toh kya hoga? Ye jyada electron emit kar paayega.
[7:01]Isliye emitter ka doping sabse jyada kiya gaya hota hai.
[7:04]Base ki baat kar le toh base ki size sabse kam hoti hai, aur iska jo doping hota hai, iska doping woh bhi sabse kam hota hai, yaani bahut hi kam holes hote hain isme.
[7:15]Ab last, collector ki baat kare, toh collector ki size sabse jyada rakhi hoti hai, aur iske andar jo doping hota hai, woh emitter se kam hota hai.
[7:25]Emitter se thoda kam hota hai, aur base se thoda jyada hota hai.
[7:31]Ab question aayega ke collector ki size sabse badi kyun rakhi? Kyunki collector ka function kya hai? To collect the electron.
[7:37]Ab electron toh collector mein kahase bhi aa sakte hain, jaise ke emitter mein se bhi aa sakte hain, base mein se bhi aa sakte hain.
[7:44]Agar collector ki size bade rakhenge toh ye collector acche se electron ko collect kar sakega.
[7:50]Toh ye sari baatein thi hamari ye construction ki.
[7:53]Ab hum dekhenge ke diode kab active hota hai, kab woh deactive hota hai yaani uske forward aur reverse bias ki baat karenge.
[7:59]Yahan pe do circuit diagram bana ke rakhe hain, circuit one, circuit two.
[8:04]Ab ye dono diagram pe se hume batana hai ke kaun si condition mein hamara transistor active hoga?
[8:11]Jaise ke yahan pe humne kya kiya hai? Yahan pe humne emitter aur base ko connect kar diya hai aur yahan pe hum input de rahe hain.
[8:18]Toh kya collector mein hume output milega? Kya ye connection active transistor ke hain ya nahi?
[8:37]Toh transistor kab active hai, kab woh active nahi hai, kab current flow karayega, kab current ko rokega, toh woh samajhne ke liye hume do junction ke baare mein samjhna hoga.
[8:47]Kaun se do junction? Toh dekh lete hain. Yahan pe ye ek junction hai, ye wala junction.
[8:52]Theek hai? Ye junction kiske beech mein hai? Base aur emitter ke beech mein hai, toh ise hum bol denge emitter junction.
[9:07]Theek hai? Base aur emitter ke beech mein hai toh emitter junction ya emitter base junction bhi aap bol sakte ho. Theek hai? Ab ye wale junction ki baat karte hain, toh ye kaun sa junction hai? Base aur collector ke beech ka, toh ise base collector junction bhi bol sakte ho, ya phir hum bol denge ise collector junction.
[9:21]Theek hai? Usi tarike se yahan bhi dekh lete hain, ye jo junction hai hamara ye wala, ye kaun sa junction hogaya?
[9:27]Ye hogaya hamara emitter junction, aur ye junction jo hamara hai woh kaun sa hogaya? Ye hogaya collector junction.
[9:35]Theek hai? Ab ek cheez aapko yaad rakhni hai kaun si, ke jab emitter junction forward bias mein ho, tab hi hamara transistor active mode mein aata hai.
[9:48]Kaun sa junction forward bias mein hona chahiye? Emitter junction forward bias mein hona chahiye.
[9:54]Forward bias yaani kya? Emitter junction ko forward bias karenge, iska matlab true connection, true connection yaani plus plus, minus minus.
[10:01]Plus plus yaani kya? Ke hamara jo p-type semiconductor hai, ye wala base, ise hum positive terminal ki battery se connect karenge aur ye n-type wala hai, use, yaani emitter use negative terminal ki battery se connect karenge.
[10:17]Jab aise connection karoge aap, tabhi jaake hum bol denge ye jo hamara emitter junction hai woh forward bias mein hai jiska matlab hamara diode active hai.
[10:27]Ab question aayega ke ye jo hamara junction hai, collector junction, ise agar hum forward bias kar de tab kya ye active hoga? Toh tab ye active nahi ho paayega.
[10:39]Kyun nahi ho paayega? Woh bhi dekh lete hain. Ab ye junction jo hai, collector junction, sorry emitter junction forward bias mein kiya.
[10:46]Forward bias mein kya hota hai? Hume pata hai ke depletion layer kam ho jaata hai, potential barrier kam ho jaata hai, jisse karke aasani se electron junction ko cross karke chale jaate hain, current ka flow ho jaata hai.
[10:57]Ab emitter mein humne kya kiya tha? Doping bahut hi jyada kiya tha, yaani emitter ke paas bahut sare electron hain, jisse karke bahut sare electron flow karenge, current ka flow milega.
[11:08]Ab yahan pe ye jo hamara collector junction hai usme bhi forward bias karne par depletion layer kam hoga, potential barrier kam hoga, lekin collector ke paas doping kam hai, yaani number of electrons kam hai, yaani current ka flow bahut hi kam hoga.
[11:24]Isliye humesha se hum kya yaad rakhenge? Ke jo emitter junction hai use hi hum forward bias mein rakhenge, toh automatically dusri cheez reverse bias mein ho jaayegi.
[11:34]Toh yahan pe dekh lete hain ye kaunsa hai? Emitter junction, toh ise hum kis mein rakh denge? Ise hum rakh denge forward bias mein.
[11:41]Toh automatically ye jo hai ye kis mein ho jaayenge? Reverse bias mein ho jaayega.
[11:46]Theek hai? Achha, forward bias yaani kya? True connection, correct connection, positive ke saath positive ki battery ka terminal, negative ke saath negative terminal jo battery ka hota hai woh yahan connect kar denge.
[12:00]Theek hai? Ab ye hogaya kaise active hota hai, kaise biasing hoti hai.
[12:04]Ab yahan pe hum iska symbol bhi dekh lete hain, n-p-n transistor ka, toh aisa kuch circle bana dena, aise teen laane aise bahar nikal dena.
[12:12]Theek hai? Hamara ye hogaya emitter, ye hogaya collector, aur ye hogaya base.
[12:18]Base humesha beech mein hi hai emitter aur collector ke.
[12:21]Theek hai? Achha, ab emitter kiska hai semiconductor? N-type ka.
[12:28]Theek hai? Yahan pe base jo hai woh p-type ka hai aur ye collector n-type ka, toh collector n-type ka.
[12:31]Ab arrow ki direction important hai, yahan pe aapko arrow ye side batana hai, emitter ki side ya p se n ki taraf jaate hue batana hai.
[12:40]Aisa kyun batana hai? Kyunki humne p-n junction diode ka aisa kuch symbol dekha tha jisme kya bola tha? Jab p-type positive terminal ke saath, n-type negative terminal ke saath connect karoge tab forward bias condition hogi.
[12:51]Forward bias condition mein current aise flow hota tha p se leke n, toh yahan bhi current p se leke n flow hoga.
[13:00]Theek hai? Ab yahan p se n flow hua, yaani base se emitter mein chala jaayega current.
[13:22]Theek hai? Ab aise hi hum agar p-n-p transistor ke symbol ki baat kare toh same symbol hoga, p-n-p likh denge, arrow ka direction ye side kar dena p se leke n.
[13:32]Toh ye sara introductory video tha. Ab hum next video mein iska operation dekhenge ye work kaise karta hai.
[13:38]Toh is video mein bas itna hi so till then read hard, work hard, thank you very much.
