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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7ukDKVHnac4.html
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!
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.
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.
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 😃
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 👍
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.
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.
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.
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.
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"!
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!!
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
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!
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! 👍
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!
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 :)
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 😊
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.
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.
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.
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!
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)
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?
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
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.
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.
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?
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.
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.)
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.
I had been watching your RU-vid post. It's very informational and educational. Thanks for your hard work. I own Simpson 260 6xlpm and 262. From RU-vid 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
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.
What type of configuration or what is the correct terminology when a preamp uses NPN first stage then PNP second stage? both transistors are silicon but the one stage is NPN and the second stage is PNP, this must be called a certain configuration
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.
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.
hello. I'm trying to service my analog multimeters, but they're old and I'm not getting components to replace. can you tell me where you buy special components like diodes, resistors? thanks.
@@w2aew I'm sorry I didn't introduce myself. I'm Emílio Abrahão, I live in Brazil. Of these distributors that you introduce me to, I only know the mouse, but I didn't go in to research the components I need. Thanks for letting me know the vendors you know.
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...
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.
Clearly, I need to go back and start over with electronics. I was unable to get an electronics simulator to produce even close to the same numbers shown on your meters. Everything was very well explained, it just didn't align with what "I" am trying to verify. It's unfortunate, but these kinds of videos where the material is clear and practical but I'm unable to piece any of it together make me want to give up electronics entirely. Nevertheless, thank you for your content!
Hi, I had been watching your youtube and really appreciate the hard work your doing. I own Simpson 268 6xlpm and 262 series 2. I learned so much how to use the 260 from youtube. I hope you could help me how to use the Simpson 262. I had been searching online for help but I could not find any help in regards to my 262.( it seems they have different readings ) I hope you could post Simpson 262 and 269 tutorial on how to do reading ohms and voltage. Thank you so much.
