The main problem I have noticed why people don't know how to use transistors, is the teachers. They are starting electronics with transistors, and immediately dive into the deep end of transistor analysis and different types of transistors, without actually ever explaining what they are and what they are used for. Even on the first introduction to electronics, teachers start throwing around words like FETs, BTJs , IGBTs, NPN, PNP, emitter, controller, base etc. never actually telling students what those acronyms mean. For example, a few years ago, I participated in 1st year students electronics course in an University as an undercover student to troubleshoot why everyone was failing these lessons. I have a few engineering degrees and although my electronics degree is from the the early 2000s, I could barely follow the class and had to correct the teacher several times on critical (possibly fatal) theoretical errors, because he thought they were so obvious everyone would know that he was talking about only a very limited use case with a lot of safety precautions in place. With the excuse that I had "just read on a the internet that isn't it like this instead?", since I couldn't just let those things pass. Then the after the 2nd week, theory was over, and we moved to lab to start building a full audio-amplifier. Basically, everyone just followed instructions, but didn't understand anything they were doing, and learned even less. I won't name the school, state or country The teacher was a former electronics virtuoso from a top name company (that still did consulting for them, but had downshifted to teaching), but he was so disconnected from beginners, he was talking and teaching to them as they were all post-graduate students, and just excepted everyone to be at that level coming in to the first electronics lesson. Also, for some messed up reason, physics I and II were scheduled AFTER the electronics courses.
Many many thanks for explaining how easy it is to use these little devils. I have lots of transistors, but never use them and stick to simple circuits for fun, but now that you have explained them to me, I will start to use them in my circuits and get all the benefits that they bring as well as enjoying electronics more. Thank you so much, Joe
Excellent Explanation . you taught me so many things in just 27 mins which my college failed to teach in four years. please keep making the videos which is very helpful for knowledge seekers like me. Thank you so much
Another excellent review deepening my understanding. I'm an Amateur Radio operator and electronics hobbyist since childhood. This is an area that I clearly grasp but still was not fully confident. Logic was easy, but other applications are now much more clear. My Sansui QRX 7400a is clearly an example of class A B amplifying. But PWM and other applications I was not quite clear on. Your examples are very helpful, thanks again..
Exactly what I'm looking for. Not just the bare explanation of how a transistor works, but even several examples what they are doing and above all why that's important. Cause, I never understand realy why I should use a transistor as a switch after e.g. an push button. Direktly saved in my learning list! Thanks
Ahhh, this is outstanding stuff for the audience you intended this for & I most definitely count myself as part of it! I'm in the "Super eager-to-learn electronics enthusiast w/zero formal schooling & 100% self-taught" & transistors are like the Next Big Step for me that I've procrastinated LIKE CRAZY on implementing in any of my projects all just bc of how intimidatingly arcane it was for me to try & learn even the basics about them w/o any primer. Pretty much any "intro" to transistors & semiconductors in general might as well be written in sanskrit if you don't have a grasp on the lexicon going in, so thank you for the effort to help bridge the gap for people like me!
Thank you sir, now I know how touch buttons on certain old elevators work on the inside ! I’m a lift mechanic and nobody could explain it to me on a component level!
Yes it's like sales people that read from the back of the box, but this is all very interesting. I guess there is an attitude to things that, nobody expects anyone to use a soldering iron any more.
Absolutely outstanding presentation which leaves more room for more. Particularly interested in RF amplification applications and also discussions about filtering in all types of amplification using transistors. Terrific presentation as usual. Many thanks. 73, NZ5i
Your approach to teaching is unique, practica, clear and previous!! It’s seems all so natural and easy to explain these topics your way!! But it’s clear that there is a lot of preparation An planning before each video. Thank you very much!! I just discovered you today but U will come back often!
Salam dorud. I suspect you're Iranian. That makes you the second great Iranian electronics teacher I've found on YT. You're tutorials and contents are fantastic and you're channel will grow fast. I'm from Tehran.
"trite" - awesome. that is a better word choice than most native speakers would make. i had to watch this again after your recent transistor magnum opus.
Great way of high side switching n-channel mosfets.... Use photovoltaic opto isolators. The isolator's output can be floated on the mosfets source. Thus gate-source voltage can always go high enough to ensure full on.
Photovoltaic couplers are generally pretty slow and the last time I looked (years ago) they were quite expensive. Still, they are a good solution for some applications.
Well, I'm positive i learned something new - but i also feel i may need to watch this many more times! Easy to understand once you get used to his accent and speech speed.
very very very very very useful channel! Thank you a lot , continue like that 🙏 I have idea why You sir don't use a plastic table to draw not loose paper 🙂.
Good video! I would like to see more information on how to create constant current supply for led and laser diodes. There’s not a lot of very good videos on cc supply. Cheers!
When switching a motor or anything else with a coil, use a feedback diode! This is to avoid/cancel back EMF. Without it can ruin your funny experiments with transistors pretty soon.
Great contents as always ,congrats. Could you make a video explaining inductor the same as this video(example: how exactly inductor oposes the Change in current,)please Iam stuck in electronics until I grasp this
@@elewizard its true. Not only for integration of small electronics into big machines, but you can add complexity to circuits simply by having an entire secondary circuit connected via transistor. I use them for all sorts of stuff, almost as much as I use diodes.
Nope, this configuration is called "Common collector" the circuit is OK. There is a dedicated video about this circuit on the channel. Look for DC motor speed controller video on the channel for detailed information on this subject.
One type of transistor serves as an inverter in one piece. Solar power banks use it for the Nokia 5110,6110,7110 series. The transistor can invert the 3.2v safely to 6.9 v when loaded, and can operate a 6 v cleaner motor at high speed from a little 3.7 v Nokia battery.
@@Enigma758 A common collector (CC) amplifier or "emitter follower" is a good circuit to use when you want to apply a constant (but variable as required) voltage to a load that varies in impedance. Remember that an ideal voltage source has zero output impedance - the voltage stays constant no matter what current is drawn from the source. The CC amplifier has high input impedance and low output impedance. The output impedance isn't zero, so you don't get a perfect voltage source, but it is low. Just what the ratio of input impedance to output impedance actually is depends on the current gain of the transistor. The higher the gain the higher the ratio of input to output impedance. That gain will vary somewhat from one unit to another of the same type and will vary with temperature. Usually with a DC motor with brushes what you want to do is control the speed , which is reasonably proportional to the applied voltage. If the mechanical load increases while the applied voltage is kept constant, the current increases, and vice versa. That low output impedance of the CC amp is just what you need. Overall the performance isn't great, but can be quite adequate for lots of purposes. (If you need really good speed control you'd typically use a tachometer in a closed-loop system, though you can do a pretty good job by measuring the back-EMF from the motor, which tends to be very linear with speed). There are circuits where you might add some extra resistance in the emitter circuit of a CC amp but that moves the circuit farther away from being an ideal voltage source if the load is in series with the added resistor. If a CC amp is used as the final output stage of an amplifier with feedback, sometimes a small resistance is used to isolate capacitance that may be present with the load. Capacitance can cause a phase shift that can play havoc with the stability of the system and the resistor can mitigate the problem. This is common with audio power amplifiers. Both JFETs and MOSFETs can be used in "source follower" (common drain) circuits for extremely high input impedance. The difference between gate voltage and source voltage is not as well defined as with BJTs.
@elewizard I have similar vice type and without filter the sound is not good. In order to avoid post processing my audio every time I use Sure MV7 with their software. Once you setup the filters the audio is good every time. My configuration for creating RU-vid videos is: I use SurePlus Motiv for the microphone , then it goes into NVidia Broadcast as I apply some extra filters and background blur, and then it goes into OBS Studio. I don't use filters in OBS though it has plenty. Just to setup my scenes, screen. My first video had terrible audio when I used my Webcam microphone.
....IMHO: I think that for many people, working with various "electronic" devices, etc., we often find that, if any circuit board "craps out", it's often faster, and cheaper to just replace the "entire board(s)", rather than trying to sort out any specific faulty components on the "bad board"...So, although we may study "transistors", and solid state devices',... unless we specialize in being an electronics repairman/bench technician",... we never get "good" at finding specific "faulty components", and replacing "them".... instead, we merely replace larger boards, entirely...
wow washing someone describing my hobby in such a confusing way troubles me. first vacuum tubes and FET field Effect Transistors are voltage contorled devices. a BJT is NOT Binary Junction Transistors are current controlled. I stopped counting at 30 misleading statements, If anyone wants to learn electronics this is not the channel. a great example of " If you can't dazzle them with brilliance baffle them with BS "
Yeah, WOW man. Wizard actual. You seem to use English far better than many of my American neighbors lol. I'm already using a custom open source 'Solid State Tesla oscillator' circuit (by Master Ivo), employing SiC power mosfets, running a [bifilar pancake] Tesla Coil based 'single wire transmission line', improvising simple little analog circuitry for probing my system. Even so, this vid managed to: a. Rock my world b. knock my socks c. cause me to execute a backflip Question: How would YOU replicate Tesla's trick of using an old telephone handset to 'listen in' for null points along a [scalar/longitudinal]TX line? F resonant is around 120kHz, must i use a heterodyne to get audible tones, or can it be managed more simply? I think Tesla was also using telephone handset with a 'coherer' RF detector to make just periodic 'beeps' out around NYC while his transmitter was oscillating. A simple 'periodic beeper' to sound off when my step-down 'receiver' transformer is getting power from the line (or spherical terminal), would be helpful for me to demonstrate reception inside a grounded faraday cage too - any tips, my guy? ❤ cold
I would not call the simple 2-transistor current limiter a "switch." The main transistor is essentially switched ON below the current limiting threshold, but as that threshold is approached the whole circuit begins to operate in linear mode. It is important to remember that the main transistor power dissipation may be quite high and a heatsink may be required. This circuit isn't high precision and you'd get a moderate amount of variation from one unit to another, but it is plenty good enough for lots of applications.
Good points, the circuit is not high precision, you have to add some other components to make it more precision. Components like OPAMP. I will explain it in one of my upcoming videos 👍
