Introduction to Bipolar Junction Transistors (BJTs) | Basic Electronics

In this high level introduction to bipolar junction transistors (frequently known as BJTs), Josh goes over some of the higher level topics of BJTs, talking about the symbol, introducing the base, collector, and emitter, and going over their applications as either a switch or an amplifier. As this topic is surprisingly in-depth and can be quite complicated, we highly recommend checking out our other tutorials about BJTs as well to get a more comprehensive understanding of how these fundamental electronic components work.
And here's the written tutorial JB put together on using a BJT as a switch: www.circuitbread.com/tutorial...
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[@riemanndiy6693]

at 10:28 it should be ib(beta)=ic

[@CircuitBread]

Yep, dang it. ie = ib + ic but ic = ib * beta
Good catch, thank you!

[@StEvUgnIn]

@@CircuitBread Make something to cover on the video

[@znhait]

I was great at circuit analysis with resistors, capacitors, and inductors, where I could rely in my mathematical abilities. But with electronic devices, while the math was simple, what tripped me up was all these different configurations and regions of diodes and transistors. There are so many different permutations that everything becomes a guess and check. Personally, I wish schools would have a course on semiconductors at the physics level before introducing it at the circuit level. It becomes much more intuitive that way. At my school, most of the professors in the Electrical and Computer Engineering department that taught classes that dealt with transistors and diodes got their degrees in physics, not electrical engineering--obviously, they intersect, but you get the point. Saying all that, once you understand a transistor, its practical use will fascinate you.

[@BigDaddyGarth]

Needed this thanks 🙏🏾

[@josiekelly7950]

Thank you this was so helpful!!

[@jeromesimms]

Nice 👌Just what I've been doing. Keep up the good work as I find theses videos so informative

[@CircuitBread]

Thanks Jerome!

[@zetaconvex1987]

Thanks for that. Keep up the good work.
A simple mnemonic for the arrows: NPN = Not Pointing iN
It also helps to think of the arrow as a diode, so you know the voltage drop across base/emitter is 0.7V

[@CircuitBread]

Thanks! For some reason, this particular mnemonic doesn't stick in my head as well as it should but when I do remember it, it saves me some time having to look it all up again.

[@tridium-go6hw]

I use a similar but easier (for me) mnemonic: Points, Not Points. In a "P"NP transistor the arrow "Points" to the base. In an "NP"N transistor, the arrow "Not Points" to the base (doesn't point to or points away from).

[@globalassistance1050]

Many Thanks!

[@Electronzap]

Good topic :)

[@damirshodiev673]

love your ohm's law poster on the background

[@CircuitBread]

You can download the PDF from our poster gallery here: www.circuitbread.com/extras/poster-gallery 😀

[@acestudioscouk-Ace-G0ACE]

Thanks for this, I now understand how a NPN works as a switch and an amplifier. I need to watch a few times for it all to sink in. It takes longer to learn when you are geriatric! LOL

[@CircuitBread]

😂 I must be a geriatric as well because I have to go over these principles many, many times as well to make sure I understand them.

[@acestudioscouk-Ace-G0ACE]

@@CircuitBread LOL!

[@arashyusefi1889]

Thanks 😊👍🙏💯

[@sbfarmer8]

can you always with all types of transistors put load before the collector or after the emitter?

[@jeromesimms]

In general usage, you would want to have the load after the emitter.

[@Electronzap]

Load position in relationship to collector and emitter depends on the type of circuit you are building. Switch and current source circuits need the load on the collector side. Emitter follower circuits need the load on the emitter side.

[@CircuitBread]

Yep, spot-on. While the load after the emitter is probably the most common usage, there are many different configurations. I considered going over the different options in this video but was worried about both overall tutorial length and not being sure that I would do it justice.

[@albertwilliams5532]

When electrons move from emitter to base in npn transistor, then why we point the current flow(flow of electrons) arrow from base to emitter? Thanks much for the video.

[@CircuitBread]

Current flow is the opposite of electron flow. Which is a bummer but it's the way we look at things as electrical engineers. Other than looking at devices closely (like in this video), just work with current flow and don't worry about electron flow. It is confusing, though.

[@martinkuliza]

1:37 Yes there are 2 T's in Emitter
However Collector has 1 L and 2T's as well
LOL.... Just fucking with you

[@StEvUgnIn]

You should make an IGBT video

[@CircuitBread]

I had hoped we were done with semiconductor topics but I've gotten enough requests that I think I will do this. I'll put this in the queue, thanks for the feedback!

[@CircuitBread]

Ha! I went to put it in the queue and noticed it was already there. Alright, it's gonna happen.

[@StEvUgnIn]

@@CircuitBread Thanks.

[@farmerjon5532]

Thanks. FYI, your site is down atm.

[@CircuitBread]

Thanks for the heads up! Can you try again, it looks like it’s up now on our end.

[@farmerjon5532]

Good to go now, thanks

[@hajardj3593]

hey can you please add english subtitle , thank you .

[@CircuitBread]

Hi! We're actually planning on going back and getting actual subtitles (not just computer generated) for each of the videos and are hoping to get that done by early next year. Eventually, we're hoping to get them all translated to a few other languages (the subtitles) but we'll have to see how things go. Thanks for the feedback!

[@suzaku1083]

Add the Arabic translation, please

[@CircuitBread]

As CircuitBread starts to generate income (soon, we hope!) our goal is to provide accurately translated closed captions for all of our content to be able to help even more people. I don't think that'll be for at least 2-3 years, though, unless our growth trajectory changes.

[@suzaku1083]

@@CircuitBread thank you❤️

[@abodahmed4054]

احا مش فاهم

[@suzaku1083]

مفترض يضيف الترجمة

[@adam-pi9de]

سنة كام يا شباب ؟

[@suzaku1083]

اظن يختلف من دوله لدوله لكن عندنا في السمستر ٣ في الجامعه

[@adam-pi9de]

@@suzaku1083 احنا عندنا ثاني سنة في الثانوية

[@suzaku1083]

اجل المنهج يختلف 😂