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- Опубліковано 22 лип 2024
- NOTE: The horizontal axis of the characteristic curve plot were mislabeled as Vbe instead of Vce in one or two spots. The downloadable video notes have been corrected. This is a back-to-basics tutorial video on the bipolar junction transistor, or BJT. While there are just two basic types (NPN and PNP), the video mainly discusses NPN types. It reviews the schematic symbol, typical pinouts, & basic operating principles of linear and switch operation. We dip our toe into the physics a little bit, and then do some experiments on the bench to demonstrate the linear and switch / saturation mode of operation. Links to the notes and other videos appear below the chapter listing:
00:00 Introduction
00:09 Types of Bipolar Junction Transistors (BJTs) - NPN and PNP
00:39 Schematic symbols and transistor terminal names
01.06 Common package pinouts
02:05 The common diode or junction diagram
02:43 Basic principles of operation of the bipolar transistor
03:50 Linear and Switch regions of operation
04:54 Transistor characteristic curves
06:37 Linear operation details
09:41 Brief look at the physics of operation
12:51 Summary of the physics
13:14 Linear test circuit schematic
14:15 Demonstration of linear operation
17:30 Switch / Saturation region of operation
19:04 Saturation test circuit schematic
19:28 Demonstration of switch / saturation operation
21:15 More bipolar transistor videos
23:07 Closing
Video Notes:
www.qsl.net/w2aew/youtube/Bipo... - Наука та технологія
I'm a big fan of these videos that are very nicely made. But at 10:00 I'm a bit concerned by the over simplification and the misunderstanding it could imply. For exemple, even if it's not actually said, I think that many people will understand that the N region having extra electrons means it's negativity charged...
I suggest you link to this explanation for more details on the physics:
ua-cam.com/video/7ukDKVHnac4/v-deo.html
Pinned this comment so viewers can find the more detailed physics video
Please continue creating more "Back to Basics" content. Your knowledge is incredibly valuable and should be shared with others who have the same interests and passion for electronics. Thanks for your sharing!!
This is absolutely lovely. All of what one needs, none of what one doesn't, and delivered clearly and concisely. No 'flab' but not rushed. This should be a template for textbooks and instruction everywhere. Great stuff.
As always, crisp and clear. We appreciate every second you put into your content! Topclass!!
Nice to see you back. Hoping to see more of your quality content in the future.
Perhaps a topic for your channel:
An easy transistor Low noise amplifier.
It connects your appreciation for HAM radio and electronics.
Keep up the good work 😃
Hello from a fellow ham and EE. Your knowledge transfer and delivery style are so incredibly efficient. I swear every one of your videos fills in some gray area that has persisted through my EE career. Thank you for such informative content!
@CirrusSecure Thank you - I'm just a lowly BSEE
I also refer new Hams to this channel. I struggled with a lot of the modulation parameters and things like FM deviaation, oscillators, and anything beyond physics level E&M, and electronics that I got in school. You made it quite clear what they answers are wanting, but also why they are important things to know.
Watching 25min of your video is better than attending electronic class during my time in 1980s. Thank you so much.
You should have much more subscribers and views. Your channel is a treasure for us and future generations. Alan, I recommend you create a Playlist with all these Bipolar Transistors videos, and maybe the same for other types of videos. Keep a backup of all your videos, just in case.
Back to basics are the best and glad to see you again mr. Wolke. I really enjoy watching your educational videos.
Alan: What can I say that hasn’t already been said. I too am a fellow ham, a telecommunications engineer and repair technician. Your videos are a great source of, as one commenter said, education that aptly fills in the gaps! Thank you so much and please keep the basic electronics videos coming from time to time.
As a ham and an electronics hobbyist, I really appreciate the knowledge and effort you impart to the community. I learned a lot from your practical ways of teaching than reading books. Keep it up! Looking forward for more circuit tutorial videos 👍
I feel I've learned a lot from your videos, which include just the right combination of theory and practice while keeping the math mercifully simple. Back in my school days, I hated math classes, because I could see no real-world applications for "equations", "imaginary numbers", "phasors", "vectors", etc. Now I'm beginning to wish I'd spent less time staring out the window and more time solving math problems! Fortunately, nowadays there are inexpensive devices which excel at computation.
Superb job explaining the junction physics without lots of scary math! Alan, you REALLY should release these "back to basics" videos as a "digital boxed set"!
Another excellent description. I never understood transistors from the typical path of diving deep into electron holes, doping, etc. You hit just enough to detail to make sense while talking about what we really need to know, like the relationships between the voltages and current around the transisitor.
your back to basics videos are the best on youtube..you explain very nicely 👍
I've been an engineer for over a decade but I should get back to basics. Thanks.
Always find something to learn when watching these. Thankyou for your general rule of thumb inclusions.
I'm very blessed to have such a great teacher. Thanks!
Alan, THANK YOU! ... I have today passed novice licence exam ... your great work was an will be always big help! ... still so much to explore ;)
Fantastic! Congratulations!
Back to basic videos are my favourite ones! Always crisp and to the point
In the past week I've watched #185, 113 and 114. NOW you make this video too! Thanks! I love the way you used the meters to display this.
Excellent video! You helped me understand in 23 minutes what electronics teachers I had 40+ years ago could not in many more hours! Thank you! I’ll be mining through your videos for more tidbits like this, and I look forward to anything new! 73, de Larry, N2LJ
Great job, thanks!!! Greetings from Argentina!!
Just want you to know how you've increased my enjoyment of electronics by your teachings. I've watched so many of the back to basics videos multiple times to reinforce theory and I love how you then show the theory in a practical example. I usually then try to duplicate the experiment for myself and the math for the circuit. That drives everything home.
That's the most concise applied physics lesson I've ever had, especially relating to semiconductors. I wish I could have seen that years ago. It really clarified some murkiness around BJTs that's haunted me a while. (I really dislike "black boxes" I don't understand. 😁) Thank you! 👍
I really love your videos. There is optimal amount of theory and practical demonstration. Thank you!
This is soooo good!! I am so happy that I can understand these topics, thank you w2aew!
Another fantastic video. I was waiting for more content, it's been a while, but as always, you delivered! This is probably my favorite channel. I peruse your videos quite often as they are very helpful, simple and to the point!
Fantastic content as usual. I always learn SO much from your videos. You give every topic a very fair, and in-depth-enough treatment to explain the subject thoroughly but at the same time very concisely. Thanks for sharing!
I really like your "Back to Basics" videos.👍
This is great! I need to actively start binge watching your channel which I should have done many moons back 🙂 Thanks for the great content as always.
Just found your channel, and I am delighted. I am a new ham interested in learning as much as possible, so these videos are perfect. I like your presentation style and the topics. Thanks!
Now, this is some GREAT educational content, concise, with all necessary background physics explained, clear examples and with perfect timing! Subbed, liked and would love a donation button too :)
There actually IS a donation button. Lower right corner of the banner graphic on my channel's homepage (also in the About page). Thank you!
Thank you, for your brilliant tutorials 👏👏👏
Thank you Alan. As always, the perfect balance between theory and practice! A useful index as well!
Great explanation 👌 Thank you for this (for me) remedial. I will start today with repeating your experiments, and review the other video's.
Hee thanks for the clear explanation and nice demo setup. 👍
Thank you for sharing your knowledge. You have a great way of presenting the information, it's clear and precise. Have a great day.👍
Very informative and clear explanation. Thank you!
Thank you for noting the opposite linear/ saturated operation for FETs! When I was learning this the first time I was very confused by that.
As always, a great video on the BJT. Thanks.
Thank you for the refresher course. Always interesting and useful !
Always enjoy watching all your videos, I have learned a lot from them. 73s~ 2WR785
Thank you sir!
Great refresher! Enjoyed watching, thanks!
Another great video, as always!
Alan, you are an amazing teacher.
Thanks.
De VU2RZA
Awesome content as always! I was just refreshing myself on BJT physics yesterday with an old textbook (old enough to show currents running "backwards"). You could follow this up with a video on the Sziklai pair to show some complementary circuitry. For the uninitiated, Its basically a Darlington pair using opposing BJT types.
Nice refresher!
I felt the same way
A very high quality post!
Thanks for a nice, concise memory refresher!
Thank you wonderful as always.
I really like this channel. There is a lot to learn here. Greetings from Germany.
Such great content. Thanks, I appreciate it
Great job. Makes it easy to understand. 👍
Well done!
That said, it's going to be hard to beat your differential pop-up book in #193! :-)
This is so clear and in particular the physics, and would have been so useful when studying the same topic in my Millman and Halkias (integrated electronics) textbook 😊
That's an old text book (1972? ... 50 years!) Maybe get a newer text?
@@willthecat3861 🤣yes indeed bought it in 1974 ... However the physics haven't changed much...
@@willthecat3861 millman was co-worker with Elbert Einstein at MIT
Thanks Alan! great video, as always!!!
Great like always.
I am glad the kitchen remodeling project is done, and we will get great presentation again.
Here are some subjects, you might consider:
PLL
Costas loop
logarithmic amplifier.
I do have a video on PLLs
Thanks, Alan! Nice lesson.
Great tutorial....cheers.
Thanks from 🇧🇬 Bulgaria!
Dude, where ya been? Good to see you back.
I find myself landing on you channel frequently by pure accident, hmmm.
I've spent a little time designing and building transistor based logic circuits and have found that 1k(collector) and 10k(base) resistors work really well with 2n3409s at 5v. Can easily achieve a 10+ fanout and comfortably managed an 8 input (N)AND gate.
I think you meant the 2n3904
good timing since we just started BJTs in class last week
Nice I love Watching Your Videos I learned Much Stuff From You Sir... thanks
Very interesting, thank you for the upload. :)
Great work, tnx.
Tysm Alan! Another great one! Appreciate it 🙏🏻 in #273 I asked for a two stage direct coupled BJT CE amp and you put it on your long list, that was 5 years ago 😁 Seems I have to check back again in 5 years 😂 damn nobody explain as good as you!
It’s a long list ;-)
@@w2aew yeah... I understand 😁
Great video again!
Yea! Back to Basics... Thanks for what you do!
Oh.. wow... Thanks a lot sir..
Another way to look at a BJT is considering it a reverse biased diode (the BC junction) whose reverse saturation current is controlled by the base-emitter junction. This explains why the VCE-IC characteristics look like the reverse VI characteristics of a diode for different values of Is.
(Just reverse the axes)
That is a *BRILLIANT* way to think about the collector I-V curves vs base current - thank you!
Again: wish you had been my professor at university. Very good explaination of the fundamentals without being shallow. 73
Merci for this video!
Two thumbs up!
Excellent!
These videos on transistor amplifiers are GREAT! Any chance you can do a video on CE amplifier bootstrapping as I see very little information online with respect to this?
Back to back to basics. I’m into it. Anybody headed to Charlotte Ham Fest this weekend?
Thank You!
Nice job.
Hi.
I was always wondering why the collector is the largest surface in a bjt?
The emitter current is the sum of base and collector current, so it has to handle the largest amount of current.
(in valves it might be logical, that the plate is bombarded with electrons.)
Where can I get one of those wireless Scope probes? Professional instruction as always. 👍
Mr. Alan, please teach us about which one better to use between ebers moll or beta consideration when using BJT. Thanks always for your great video content.
Ebers-Moll is a small signal model
top, as usual
I had been watching your UA-cam post. It's very informational and educational.
Thanks for your hard work.
I own Simpson 260 6xlpm and 262. From UA-cam help and most your site I learned a lot
specially the 260 xlpm. in regards with the Simpson 262 I can not find any tutorial.
I don't know how to use the 262 beacuse they numbered different.
I hope you could make a tutorial on how to use the Simpson 262 on how to read ohms
and voltage and so on.
Thank you
I would like to do a tutorial on the 262, but I don't own one or have access to one. The best I can do is point you to the user manual:
www.simpson260.com/downloads/simpson_262-1_user_manual.pdf
which particular difference between the circuits explains the different modes of transistor operation in the two of them?
In the saturated case, the load in the collector circuit drops enough voltage to drive the transistor into saturation when the base is biased sufficiently.
Thanks for the video. While it was strictly refresher for me, I needed something to uncook my brain before going to bed. Sometimes it helps greatly after struggling in a lot of unknown territory on project. I bookmarked a few you listed at the end. Grounded base, I don't really get it, which is incontinent since I'm rebuilding a SB-200 linear amplifier and it's grounded grid. 73, KO4SWI
As long as you "wiggle" the base-emitter junction, you'll get a larger wiggle on the collector current. You can ground the emitter and wiggle the base, or ground the base and wiggle the emitter. The latter has a lower input impedance and no miller effect, which is why of often see it used in RF amplifiers.
Thanks!
I don’t think it’s a coincidence that I just purchased a “component analyzer” Atlas Peak DC75 Pro just yesterday and been looking up curve tracers for transistors/fets and run into a video you did many many years ago and watch it TODAY 3 hours ago and BOOM all of a sudden you drop another video on the same topic? Is this a reupload?
How does this work in a for example MCP4921 12 bit DAC? with a LM4040-2.5V reference
This 0.6/0.7 gap? how can this divide 2.5V with 4096 options and still give you 0,000610352V per step.
is this 0.6/0.7 gap related the thickness of the silicon wafer?
The base-emitter voltage drop is just a consequence of the semiconductor materials, just as with a diode. Has nothing to do with the thickness of the wafer. Also, the Vbe voltage really has nothing to do with the number of bits of resolution in a DAC.
Wow, pls, pls do 1 on n and p channel mosfets too!!!!!
I have a video on the basics of FETs, including MOSFETs
Great video. However, there is something my poor dim mind can't figure out. At 9:11, you show the diode characteristic of the base-emitter junction. I think I understand that. But then on the diagram below that, you have another plot which appears to be the diode chracteric of the base-collector junction superimposed on the IV curves for the transistor. Without knowing Vbc, I'm wondering how it's possible to draw that curve. Or is that inferred by the IV curves which plot the relationship between Vbe and Ic at various Ib settings? Maybe I'm misinterpreting that curve. Maybe it's just a line indicating when the Vbc junction is forward or reversed biased.
I Love those analog meters, Im looking to purchase a couple meters for monitoring current like you are in this video. What do you recommend that wont break the bank. Thanks Man!!
The best continue to be made by Simpson and Triplett, but both would likely break the bank for the hobbyist. I don't really have any direct experience with some of the less expensive brands of analog VOMs (TekPower, Sanwa, etc.), so can't really give you a recommendation. You could look for used ones...
Is it the base current or base voltage that causes the collector current to begin flowing?
The presence of carriers injected into the base region (current) due to the voltage across the base-emitter junction, in conjunction with the electric field setup due to the collector-emitter voltage, gives rise to collector current.
🔥 👍
Just make very little but important cache , transistors base current equation is start like this , first VBE , then IC start , after that it is base current, so the equation is IB = IC/B .
And not IC = IB× B .
Second trickery part is that transistor is voltage control device and NOT current control device. To prove it you can put resistor in emitter then you will get so call degeneration, and feedback, the current through that resistor make VBE decrease then IC decrease.
Yes - when designing bipolar transistor circuits, you almost always start with the desired collector current and work from there.
Regarding voltage or current controlled - it is really both. The B-E is a diode, and your generally working your way up/down/around the diode IV curve when setting up bias and operation. So it can be thought of from either perspective equally. Generally for biasing, you consider currents and in particular, establish a base bias that is largely independent of Beta (so you have to think about Beta and base current). For small signal linear operation, you will often think of voltage control (such as small signal Vout = Vin * gm * RC). Unlike a FET where there is effectively no gate current (other than gate capacitance charge/discharge) thus truly considered voltage driven, the BJT is arguably both.
@@w2aew yes truly is both voltage and current controlled device. Thanks again for such nice video and explanations.
I think there are a few mistakes in axis labeling of a graph. Shouldn't it be Ic vs Vce rather than Ic vs Vbe?
I love your back to basics videos. I've watched all of them.
How do you amplify a 10mVPP input signal using a transistor without consuming ideal power in biasing? I know OP amps can do it.
Take a look at my common emitter amplifier tips and tricks video
@@w2aew Will do thanks.
Hi Alan. Thank you for another great video. I had a question about your simpson (the one with the mirrored scale. (I also have one very similar to that, except I also put mine in a case with the roll top cover). This meter has 'reverse' banana jacks (i.e. the jack is actually a banana plug facing out of the socket). I see that you have some adapters, and they don't look like the ones that I used (Years ago, when I first got the meter, I called simpson and complained, and they sent me one set of adaptors). But I was wondering what type of adapters you are using and if you have part numbers for them? If you do, it would be great if you could share that info. Thank you. Neil, K7WK
I actually made a short video on this: ua-cam.com/video/tfmRzkU_Y6g/v-deo.html