How Transistors Work - The Learning Circuit

Ғылым және технология

Rather than using a physical, mechanical switch, a transistor can act as an electronic switch, using signals to turn it on or off. Karen goes over what transistors are, how they work, and some different types of transistors: Bipololar junction transistors (BJT), NPN transistors, PNP transistors, and darlington transistors. Connect with Karen on element14: bit.ly/2EASjxT
Visit The Learning Circuit: bit.ly/2OIkbEQ
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Visit Project14: bit.ly/2PPrjfk
Previously, we’ve talked about how diodes work. Silicon diodes have a p-n junction. Bipolar junction transistors or BJTs are bipolar because they have two p-n junctions. BJTs are essentially two diodes in a single package. The two main types are NPN and PNP transistors. NPN transistors have two n-type regions on either side of one p-type region, while PNP transistors have two p-type regions, on either side of one n-type region. Bipolar transistors have 3 leads, one going to each region. Typically, the middle layer is the base. P-type in an NPN, and n-type in a PNP. One of the other layers form the emitter and the third, the collector. These are labelled B, E, and C. On the circuit symbol, the arrow is always on the emitter, so we can tell which lead is the emitter and which is the collector by seeing which one has the arrow. The NPN transistor symbol has an arrow on the emitter pointing out, while the PNP transistor symbol has an arrow on the emitter pointing in. Transistors act as an electronic switch, conducting current across the collector-emitter path when a voltage is applied to the base. The switch is off if there is no base voltage present. When base voltage is present, the switch is on. We know from our diodes lesson, that diodes require a forward voltage of 0.7V before they are turned "on" allowing current to flow. In a standard NPN transistor, when 0.7V is applied between the base and the emitter, the transistor “turns ON”, allowing current to flow from the collector to the emitter. With an NPN transistor, we normally bias the device so that the collector voltage is positive with respect to the emitter. The voltage across these two points is referred to as the Collector-Emitter Voltage or VCE. If you connect the base to be positive with respect to the emitter, the voltage is referred to as the Base-Emitter voltage, or VBE. For a PNP transistor, rather than needing a minimum of 0.7V on the base of the transistor, there needs to be a minimum difference of 0.7V between the VCE, collector-emitter voltage, and VBE, base-emitter voltage. If the circuit power supply is a 9V battery, the base-emitter voltage would need to be no more than 8.3V for the transistor to turn “on” and allow current to flow between the collector and emitter. If the base-emitter voltage is 8.6V, a difference of 0.4V, the transistor would be off and no current would flow. If the base-emitter voltage is 7V, the difference of 2V is greater than 0.7V so the transistor would be “on”, allowing current to flow between the emitter and collector.

Пікірлер: 857

  • @element14presents
    @element14presents3 жыл бұрын

    This content has been recreated as an eBook for easy offline reference - part one is available now for free: bit.ly/3tpT0PS Also check out the Candy Thief Alarm project Karen created with her newfound transistors knowledge bit.ly/3jlR32f Or the conversation between Karen and James (aka thebaldengineer) about transistors bit.ly/36HoGXr

  • @AntHenson

    @AntHenson

    2 жыл бұрын

    Hey, your ebook link doesn't appear to be working :/

  • @omarpalislamovic7102

    @omarpalislamovic7102

    2 жыл бұрын

    element14 presents, go to hell.

  • @darkhumorsecret

    @darkhumorsecret

    2 жыл бұрын

    You literally taught me in 7 minutes what my instructor failed to do in an hour.

  • @johnskariah1233

    @johnskariah1233

    Жыл бұрын

    You too fast

  • @U2WB
    @U2WB4 жыл бұрын

    This is an AWESOME lesson. You pulled back the veil that has shrouded this in mystery to me for years.

  • @Calmcatfish
    @Calmcatfish2 жыл бұрын

    Great refresher. I used to dabble with semi conductors as a kid, but didn't really understand how they worked. This video brought it all back for me...thanks!

  • @davidcohen9448
    @davidcohen94483 жыл бұрын

    Excellent video. Easy to understand. Logically ordered. Very professional. Like listening to a talented engineering expert.

  • @yoramalon5273
    @yoramalon52733 жыл бұрын

    Thank you for this video. Well explained and easy to understand. You are the personal teacher of so many people that acess youtube. You give joy, and self fullfilment to so many people. I cherish you in my mind.

  • @ericglover259
    @ericglover2594 жыл бұрын

    Without really knowing much of anything about electronics I could still get the idea of how this works. Fantastic....must resist temptation to binge watch entire series now....

  • @johnvictor9071
    @johnvictor90715 жыл бұрын

    I think this is the first time I've ever been able to wrap my head around this.

  • @Utubeasiangirls
    @Utubeasiangirls4 жыл бұрын

    Thanks to your simple explanation i think i finally understand PNP transistors which seemed more complex than NPN :D

  • @aaronramsden1657
    @aaronramsden16573 жыл бұрын

    Thanks, this is the only video that makes it super simple to understand without the presenters stroking their ego by trying to sound smart by overcomplicating things.

  • @entidade1000
    @entidade10004 жыл бұрын

    I swear to god I just spent 15 minutes reading about how transistors work but 3 minutes into this video I feel a lot more enlightened. The article never even mentioned why it’s called a transistor.

  • @bradzimmerman306

    @bradzimmerman306

    3 жыл бұрын

    Maybe check the first thing she says at the :25 mark

  • @entidade1000

    @entidade1000

    3 жыл бұрын

    @@bradzimmerman306 how does it feel to be stupid?

  • @bradzimmerman306

    @bradzimmerman306

    3 жыл бұрын

    @@entidade1000 I don’t know. Tell me how you feel.

  • @allis1971
    @allis19712 жыл бұрын

    This is the most amazing explanation of transistors that I have ever run across! Thank you!

  • @dgusev
    @dgusev5 жыл бұрын

    Comprehensive, easy to understand explanation. Thank you.

  • @ishaanj8023
    @ishaanj80234 жыл бұрын

    Thanks, professionally made and good for reviewing the fundamentals.

  • @dkryptonut
    @dkryptonut4 жыл бұрын

    OMG, thank you Karen.....a lot easier to understand than some of the stuff I've read!

  • @Blacksheepishot
    @Blacksheepishot5 жыл бұрын

    we owe everything to these transistors. I was working as a tube tech when these devices started to hit the market. like in all things the new replaces the old. as for npn and pnp it depends on the circuit I design. thus, a super stable low frequency tunable osc requires a small load transistor in a reverse polarity configuration.

  • @ramsys9906
    @ramsys99064 ай бұрын

    In just 7 min you cleared every thing. Teaching is an art and that's true.

  • @timornellas
    @timornellas3 жыл бұрын

    I am a new learner and found this video very useful and informative. The pace was perfect for me.

  • @hardwareng

    @hardwareng

    6 күн бұрын

    what is your progress at the moment??

  • @alfieroseburg8887
    @alfieroseburg8887 Жыл бұрын

    You have the most perfect explanation about transistor using precise circuits

  • @mockillu
    @mockillu3 жыл бұрын

    I've spent the last week trying to figure out transistors, reading a lot of material and this was one of the most helpful resources in understanding them. Thank you so much for sharing!

  • @oladayosulyman6885

    @oladayosulyman6885

    2 жыл бұрын

    Me too

  • @oladayosulyman6885

    @oladayosulyman6885

    2 жыл бұрын

    Expecially for the PNP

  • @Uvisir
    @Uvisir2 жыл бұрын

    i finally felt i understood the transistor basics now. wow that took some years to grip but this video confirmed everything ive understood and by watching this i now got it, thanks

  • @g.k.6451
    @g.k.64513 жыл бұрын

    Thanks sister. U explained every thing in a very understandable manner.pl extend your lesson further for novice and other interested.

  • @THK_88
    @THK_884 жыл бұрын

    Thanks so much .. this is a great video to understanding npn and pnp transistors .. really thank you 😊

  • @AndreasA.S.
    @AndreasA.S.5 жыл бұрын

    PNP = Points iN Permanently NPN = Never Points iN this may help with reading schematics.

  • @Limeayy

    @Limeayy

    5 жыл бұрын

    i remember this in class.

  • @rakshithakoriraj8469

    @rakshithakoriraj8469

    5 жыл бұрын

    wow.. really helpful

  • @wakefieldyorkshire

    @wakefieldyorkshire

    5 жыл бұрын

    Excellent MNOMIC Andreas, if you have any more; indeed if anyone has any more, please leave us them in the comments. They are really helpful. Thanks, hats off to you and cheers.

  • @ariztech1058

    @ariztech1058

    5 жыл бұрын

    Thanks Stevens

  • @user-wq1nm4lc7q

    @user-wq1nm4lc7q

    4 жыл бұрын

    Andreas. Thank you. This was the question raised in the mind when i was listening the lecture. How to keep in memory the arrow direction.?..you answered. Thank you

  • @naveenchandra8324
    @naveenchandra83245 жыл бұрын

    very good and detailed explanations, cleared so many doubts which i had about transistors. thanks for making this video.

  • @joelreyes8459
    @joelreyes84593 жыл бұрын

    Well. This video was very helpful! I thought to turn on an NPN transistor, I just needed to have .6v sitting at the base. Knowledge gap. Didn't realize it needed to flow through b to e. Its working now! Thanks

  • @zeds2089
    @zeds20892 жыл бұрын

    With a non-science backgorund was struggling to get a minimum jibor-jabor explanation. Thank you so much

  • @usmani93
    @usmani934 жыл бұрын

    Thank you so much for this explanation, solved a problem after a month

  • @RajendraChhimpa
    @RajendraChhimpa5 жыл бұрын

    Sincere effort to explain the smallest monster of the electronics. Also elaborate with equations. Have a nice day

  • @SB-mr2nk
    @SB-mr2nk3 жыл бұрын

    Freaking awesome video, really dispels the difficulty of learning this stuff!

  • @yummyzerg
    @yummyzerg3 жыл бұрын

    Incredibly clear explanation. Thank you.

  • @8power0
    @8power05 жыл бұрын

    BEST EXPLANATION..., I TRULY HOPE THIS CHANNEL CAN GIVE ME A BETTER UNDERSTANDING OF ELECTRONICS AND HOW THEY ALL WORK TOGETHER THANK YOU I WILL BE SUBSCRIBING !

  • @kingd3223
    @kingd3223 Жыл бұрын

    Wow, this is amazing you deliver it in a unique and short way. Thank you, god bless you.

  • @naderhumood1199
    @naderhumood11992 жыл бұрын

    You 'v got me on the right way, of the transistor. Thank you very much Karin..aptly great channel.

  • @SevenDeMagnus
    @SevenDeMagnus3 жыл бұрын

    Amazing presentation, deep but easy to learn.

  • @brandtharen
    @brandtharen5 жыл бұрын

    Will we see transistors used in a circuit in a future episode? This information is great. I haven't had much exposure to working with transistors so I'll be sure to review this video back couple of times to make sure I understand everything.

  • @maker_karen1785

    @maker_karen1785

    5 жыл бұрын

    Yup! Coming up next Wednesday! I usually do episodes in pairs, first a lesson video, followed by a project using what was talked about in the lesson.

  • @CodeCraftTube
    @CodeCraftTube4 жыл бұрын

    you are heaven sent.... Got D's and E's in physics bt now that i need PCB skills in real life you make it much much easier... thanks

  • @MaxGoddur
    @MaxGoddur5 жыл бұрын

    Taking AC voltage and turning it into DC voltage. Glad I found this channel helps clear the fog from things learned long ago. Also after searching manually through your videos could not find an explanation on the theory covering transformers and rectifying diodes and proper capacitors.

  • @EJP286CRSKW

    @EJP286CRSKW

    4 жыл бұрын

    Rud Dog There is no turning AC into DC here.

  • @Aprendiendo-Reparar
    @Aprendiendo-Reparar4 жыл бұрын

    it is a great Explanation. when somebody explainsa this way Electronic circuits become easier to understand. I'm a beginner. Thank you very much.

  • @noxiousbyproduct
    @noxiousbyproduct5 жыл бұрын

    This video has taught me more than any other video. Thanks 😊

  • @ccandrew111
    @ccandrew1115 жыл бұрын

    Darlingtons are an awesome solution for interfacing micros with stepper motors; done that a few times in the past.

  • @moisesreyes6980
    @moisesreyes69802 жыл бұрын

    Great Video Karen! Amazing explanation and easy to understand

  • @cndbrn7975
    @cndbrn79752 жыл бұрын

    Best explanation I've heard so far, thanks.

  • @UGUAGLIOOOONE
    @UGUAGLIOOOONE4 жыл бұрын

    never seen such a well explained topic

  • @samugote
    @samugote4 жыл бұрын

    I did mechanical and he did electrical. I got more interested in electronics and he helped me a bit until I couldn't catch up with him especially when he started designing power amplifiers using Darlingtons . Oh yes! I manually etched a working stereo 20x20W. That was in 1981 and now I can try catch up.

  • @mohankudva6834
    @mohankudva68343 жыл бұрын

    Great I have always wanted to learn about circuits. Thank you so much.

  • @Etrehumain123
    @Etrehumain1233 ай бұрын

    This lady is really cool, Im binge watching her tutorials. Excellent teacher !

  • @curtpiazza1688
    @curtpiazza16882 жыл бұрын

    Beautiful concise explanation!

  • @lordvectivus1
    @lordvectivus15 жыл бұрын

    Thank you for a very good lesson 👍🏾

  • @pmelectronics6676
    @pmelectronics66763 жыл бұрын

    Excellent explanation and very nice explanation. Thanks for the tutorial.

  • @nimrodlevy
    @nimrodlevy5 жыл бұрын

    Keren, thanks! Looking forward for tge next.

  • @sennabullet
    @sennabullet3 жыл бұрын

    great explanation!!! Thank you for sharing your knowledge!!!

  • @leeorshimhoni8949
    @leeorshimhoni89494 жыл бұрын

    explicit, well presented and made easy.

  • @daljitsingh2143
    @daljitsingh21432 жыл бұрын

    excellent teaching Karen...Thank you!!

  • @77tropic
    @77tropic5 жыл бұрын

    Really good explanation. Thank you

  • @cat-lw6kq
    @cat-lw6kq5 жыл бұрын

    I learned vacuum tubes first and some of the older books compare a tube to a transistor. So that made it easy for me to learn transistors.

  • @rty1955

    @rty1955

    3 жыл бұрын

    Tubes were much nore forgiving. I began designing tube circuits and if you make a mistake like grounding a grid, the plate glows cherry red hahh With a transistor, it just gets damaged and the circuit fails to operate leaving you with "ok why isnt this working?" Of course working with non lethal voltages has its benifits hahah Once I was working on a T.V. and had my hands inside while adjusting the time and my knuckle came to close to the horizontal output tube playe cap. That Hurt a LOT!!! I once got belted with the anode wire for a b&w crt. my jand felt like it was in a. Vise and then got smacked witha hammer! Ouch!

  • @cat-lw6kq

    @cat-lw6kq

    3 жыл бұрын

    @@rty1955 I've worked on both. Transistor sets you slip with you probe and short something and you blow out half the set.

  • @rty1955

    @rty1955

    3 жыл бұрын

    @@cat-lw6kq haha true. Ya gotta be careful with all.esp. now with close tolerances. Gone are point to point wiring where U can push components out if the way to get to a test point

  • @cat-lw6kq

    @cat-lw6kq

    3 жыл бұрын

    @@rty1955 those old tube sets could take a lot of abuse. My teacher would show us what would happen if parts of a tv failed by removing tubes in a working set. The set was powered on and he would pull tubes one at a time. Try doing that with a transistor set.

  • @rty1955

    @rty1955

    3 жыл бұрын

    @@cat-lw6kq how very true. He must of had silicon hands! I recall working in a broadcast T.V. studio where 21" Conrac monitors hung from the lighting grid. They replaced the covers with a screen mesh to allow for airflow. When i took it down for repair, I put it on the bench and powered it on. I could have baked a cake in that thing!

  • @boubacarsantara8085
    @boubacarsantara80855 жыл бұрын

    Very nice video Lady. Please make more simple explanation videos about electronic. Thank you so much

  • @tulpaswan_081
    @tulpaswan_0815 жыл бұрын

    Very helpful. Thank you. Hope for more vedio.

  • @michelnassr4863
    @michelnassr48634 жыл бұрын

    Thank you wonderful style in the explanation

  • @lenny108
    @lenny1085 жыл бұрын

    nice informative video, the development always goes further, bipolar transistors were replaced by PMOS that were replaced by NMOS that were replaced by CMOS.

  • @j3s0n
    @j3s0n3 жыл бұрын

    This is one of the top electronics channels out there

  • @technicaladviser8356
    @technicaladviser83564 ай бұрын

    Hi, how are you. I am really flattered. You explained very nicely and impressively. I am 60 years old man with 42 yeas experience in technical work and I have many Invented designs and many mega projects but I am living in the environment Where is no support from the government for the real visionary people. Each day I am thinking that life is not to waste and each breath is to find out the Real good way to facilitate the whole mankind, but the people who has Power but they don't have a good visionary mind. If I were sponsored by the hogher level authority, I am 100% sure that My only One development program can bring wealth to the whole world but, I am helpless to show because there is no support and sponsor for the true visionary mind people. I am very much impressed from your ability to explain and the real Seekers. Love you so very much, ❤ may God bless you.❤❤❤

  • @francismannion7075
    @francismannion70755 жыл бұрын

    Thank you for a very interesting video.

  • @Inquire98
    @Inquire985 жыл бұрын

    "Thank You", thank you very much 😁 Your presentation/video was REALLY good 😎

  • @nullhelp
    @nullhelp5 жыл бұрын

    Actually useful information for me, thanks.

  • @Jahmas88
    @Jahmas882 жыл бұрын

    Now that's an effective way to teach, great stuff, thankyou

  • @Mamoo480
    @Mamoo4804 жыл бұрын

    You simply the best.easy understanding how actually transistor works.

  • @sennapparajan.p
    @sennapparajan.p4 ай бұрын

    one of the best explained ....thank you so much...

  • @valdemirvlp5234
    @valdemirvlp52345 жыл бұрын

    WoW! great explanation, tks very much!

  • @claytonbenignus4688
    @claytonbenignus46884 жыл бұрын

    If you discuss Darlington Pairs, it would also be useful to discuss Szicklai Pairs. I understand that the Darlington Pair discussion was a teaser. Therefore, I suggest a follow up in depth discussion of Darlington and Szicklai Pairs for a future video.

  • @niwatuwayasaratne6246
    @niwatuwayasaratne62464 жыл бұрын

    Excellent description & thanks

  • @Aylafamily
    @Aylafamily4 жыл бұрын

    Just a small correction. It is called bipolar because it depends on both electrons and holes! not because it has 2 pn junctions.

  • @nengiwemangena6342
    @nengiwemangena63424 жыл бұрын

    Well explained, great work

  • @reasonablebeing5392
    @reasonablebeing53925 жыл бұрын

    Great video. Really enjoying these. One small nitpick - at 2:39 I believe you really meant to say "the small signal current flows from the base to the emitter" not "from the base to the collector". The diagram however is correct.

  • @mohamedsalama1857

    @mohamedsalama1857

    4 жыл бұрын

    Great

  • @TortureBot

    @TortureBot

    2 жыл бұрын

    I just noticed that. I was like, "Am I misunderstanding??" Guess she just misspoke.

  • @eldouble_u4361
    @eldouble_u43613 жыл бұрын

    Excellent explanation

  • @connorchapman4223
    @connorchapman42235 жыл бұрын

    These are awsome thanks for them it is nice to have a greater understanding of the components i use.

  • @dwightbacchus8002

    @dwightbacchus8002

    5 жыл бұрын

    O t

  • @roopeshkrishna34
    @roopeshkrishna343 жыл бұрын

    Awesome video.. amazingly useful..! Million thanks for sharing..

  • @samueldasari5080
    @samueldasari50805 жыл бұрын

    Very good teaching, thank you.

  • @anilchaudhary3552
    @anilchaudhary35523 жыл бұрын

    Please also explains about voltage amplification & modulation by using PNP & NPN Transistors

  • @lucysluckyday
    @lucysluckyday5 жыл бұрын

    This is DEFINITELY and EASILY the BEST explanation I've ever seen on this target level. Using those two voltage sources in the explanatory schematic was genius!!! And the explanation on vBE and vCE was something that often doesn't even get talked about in other vids.

  • @cat-lw6kq

    @cat-lw6kq

    5 жыл бұрын

    except the explanation about the PNP is not correct. The only difference is the battery in the diagram it would be flipped around so the (-) goes to the base. PNP and NPN both require .7v bias.

  • @lucysluckyday

    @lucysluckyday

    5 жыл бұрын

    @@cat-lw6kq It looks correct to me. If using the classic positive current model then the current flowing from positive terminal on right flows into the emitter and (mostly) out through the collector, where the base signaling current would need to have a voltage of 8.3V or less. In other words, if you think in digital terms (rather than analog) she is trying to show that a logic 0 applied to the base switches the PNP BJT on to allow the primary current to flow through from E to C.

  • @cat-lw6kq

    @cat-lw6kq

    5 жыл бұрын

    Suggest you buy one of those cheap transistor testers off ebay. for test some transistors with it, it will show the bias voltage and the gain. The tester has a digital readout, it shows bias (B-E) voltage and gain. You will see a bias of about .7v if the transitor is good.

  • @EJP286CRSKW

    @EJP286CRSKW

    4 жыл бұрын

    It isn't the best. Half of it is totally incorrect. Look harder. Try the PNP circuit shown and measure for yourself. The voltages are not as described.

  • @habtamusium8646
    @habtamusium86464 жыл бұрын

    thank you ! you make everything is understandable

  • @cartycartyamplifiersalesrepair
    @cartycartyamplifiersalesrepair4 жыл бұрын

    Thank you very much i really like your videos very educating keep up the good work

  • @marcelhofman9360
    @marcelhofman93602 жыл бұрын

    amazing, none of KZreadr can explained except YOU, thanks

  • @robmeredith3623
    @robmeredith36232 жыл бұрын

    I wish you were my university professor, because you just explained something better in 7 minutes than they did in 7 hours' worth of lectures.

  • @SteciMeba
    @SteciMeba3 жыл бұрын

    You explain very well, congratulations Teacher. I'm french student and i manage in english. Can i have somes transistor's applications ? Thank you for all and have a nice day...👍

  • @agentanakin9889
    @agentanakin98894 жыл бұрын

    Great refresher, thanks.

  • @jamesallen6007
    @jamesallen60072 жыл бұрын

    Excellent information, many many thanks, I have learnt alot.

  • @paisitalondono01
    @paisitalondono014 жыл бұрын

    Excelente información. Muchas Gracias.!

  • @patilganesh799
    @patilganesh7995 жыл бұрын

    For basic knowledge is a very good learn Thanks

  • @dardale9050
    @dardale90504 жыл бұрын

    Great!! You did it again. You're the best!

  • @myhobbies1288
    @myhobbies12882 жыл бұрын

    Very nice 👌 thanks for educating the world 🙏

  • @dgrewar
    @dgrewar3 жыл бұрын

    Thanks for sharing this...I learned a lot

  • @islamichistoryinbangla-IHB
    @islamichistoryinbangla-IHB3 жыл бұрын

    Hi, I'm Tareq from Bangladesh. Thanks for your nice concept.

  • @sharfazhameed6382
    @sharfazhameed63823 жыл бұрын

    Wow what a great lesson. Thanks a million

  • @SyarifHidayat-pc2ec
    @SyarifHidayat-pc2ec4 жыл бұрын

    thank you for your knowledge

  • @richardpayne9640
    @richardpayne96402 жыл бұрын

    very helpful I would have to have practical applyications before I can get it in my head Thank you!

  • @bharathvyas3654
    @bharathvyas36543 жыл бұрын

    good one...simple & effective

  • @piratec6291
    @piratec62914 жыл бұрын

    amazing explaination! this is pretty much the only video I understood. very well done! (I subbed :))

  • @autarkie123
    @autarkie1233 жыл бұрын

    Excellent video but a bit hard to follow on its own, without looking at the "previous video" you refer to. I'd suggest providing a link to it for ease of use. Cheers!

  • @SuperFreeEnergy
    @SuperFreeEnergy2 жыл бұрын

    Hello, first time I find a girl who works in the field of electronics, I am happy For watching your wonderful channel, greetings to you, my dear sister Very nice 👍👍

  • @ionationat3570
    @ionationat35703 жыл бұрын

    Thank you Karen. Enlightens .

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