Tutorial: How to design a transistor circuit that controls low-power devices
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- čas přidán 6. 05. 2011
- I describe how to design a simple transistor circuit that will allow microcontrollers or other small signal sources to control low-power actuators such as solenoid valves, motors, etc.
- Věda a technologie
I've never watched a video that was as informative and clear. Your explanations are complete without getting overly complicated. Thank you so much for making these.
PNP transistors especially, or transistor power that is used a little to warm up the transistor, so using Ohm Law is not 100% accurate :P.
your comment makes no sense....wanna take another run at it?
lol......great video mate, very well explained.
"Power used to 'warm-up' the transistor" ??
The .7V loss through the Base/Emitter calculation, is a bit more complex than, but 'like' the typical .6V
loss through a forward-biased diode. At such 'PN' junctions, the 'P'-type having a deficiency of Electrons, and so having 'Free-Holes'. The 'N'-type has an excess of Electrons ! (I'm keeping it simple here...).
Now where they are physically touching, (and no voltage applied), for so many atoms thick in the lattice some of the excess flows into the deficiency, creating an Insulating barrier at the physical junction !
As a result, even when 'Forward-Biased' from a voltage source, a Diode needs at least about .6V just to break down this barrier, before it starts to conduct, so you will always loose this!
A similar effect(s) are going on inside most typical Transistors. (Hence his '.7V' loss in his calcs).
(1) For a Diode, this voltage loss is NOT dependent on the LOAD after the Diode! So for example, you could connect 5 diodes in series, for a precise 3V drop, or 10 in series for a 6V drop, irrespective of the load !!
(2) This 'Insulating' barrier at the PN junction, can be considered the 'Dielectric' of a capacitor, so our Diode is ALSO a Capacitor, with the 'plates' being the P/N materials area themselves.
NOW it get's interesting though!! as the higher the 'REVERSE-Bias' voltage across the Diode, this FORCES an even LARGER non-conducting 'neutralized' gap/barrier. 2 main things control capacitance....
The area of the 'plates', and the 'space' (dielectric) between them. So what do we have now???
A solid-state Voltage-Dependant Variable-Capacitor !!! Yep... and it is utilized a lot these days.....
although now 'Special' Diodes are made to take advantage of this effect, called 'VariCap-Diodes'.
Sorry about all that... :-)
I just get 'excited' playing with software like 'Circuit Wizard', that allows you to design on screen virtually any electronic circuit including virtually all elect/electronic components & IC's, see it all run in REAL time, monitor ALL voltages & currents from ANYWHERE in the circuit simply by mouse movements.
Not to mention auto creation of your PCB & all artwork when you are ready, with auto track routing.
ALL before you touch your soldering (not the American 'soddering' :-) ) Iron. Have fun !!!
There are several components to learning electronics. One place I found that succeeds in merging these is the Gregs Electro Blog (check it out on google) without a doubt the no.1 course that I've heard of. Check out this amazing site.
When the transistor turns off, current flowing through the coil will cause a voltage rise on the collector. If the voltage rise is high enough to turn on the diode, current will flow through the diode and limit the voltage at the collector. The problem is that the diode cannot turn on instantly. It takes time for the diode to start flowing current. The capacitor smooths out the rising voltage, and gives time for the diode to start conducting.
Applied Science that part was curious, I was wondering why the diode feeds it back, wikipedia said it feeds the back emf back into the solenoid to lessen the change in current it experiences when turned off, love it.
With the capacitor it make sence. But in all my life I never saw that capacitor to ground in Relay circuit. i red the use fast diode or low threshold voltage diode (Shotky?)
schottky diode will just fine.
Your 5 volt input may have been solid between ground and +5v. I always put a 47K from base to emitter to deal with any leakage currents if the input is inadvertently left open, either by design, or by a failure mode.
amazing video mate! but, could you tell us what diode should we use for this clamp?
I’ve watched dozens of transistor vids looking for exactly this info and none of the others put it so plainly and comprehensive. Thank you.
This video should be shown to everybody starting electronics... No talk of doping and PN junctions, show them this first so that they get a picture of what they are doing.. Too many electronics courses start at the microscopic level.
JonathanAnon because those courses are made for engineers . For hobbyists this is probably enough. For an engineer this is not enough.
Even engineers would benefit of easier introduction to the matter.
@@EdwinFairchild But the introduction at microscopic level kinda kills the interest in my opinion. I like to develop interest in something before getting started.
@@curiosity551 thats what i mean, if interest is the issue which implies a hobbyist, then ignoring the physics part of it is just fine. For an engineering perspective you dont have the luxury of interest, you NEED to know the intricacies whether they interest you or not.
@@EdwinFairchild if you know it all, why are you here?
Dammit, I wish the internet was around when I was in school!! You kids are sooo lucky to have all this knowledge available instantly!
--OldGuy :)
I've been thinking that for years. I wanted to understand and know how to do many things while in my youth but had no available quick easy answers like now. This guy basically covered a 50 page chapter in 20 min without going to the library first. This information would have taken most of a day to learn, if I found the right book. Having someone explain and show examples is so much better than reading about it. Kids these days have no idea how much easier it is to acquire information today compared to 25+ years ago.
Humble boomer brag
Yeah, but now they use it just to watch non educational stuff !!!
C'mon now! Radio Shack had a "101 Electronic Circuits You Can Build " book you could buy...Healthkit offered radio controlling stuff (RC airplanes) and amplifiers...remember the ol' crystal radio? - I built one using thin lacquer coated copper wire, a simple crystal, a empty toilet paper cardboard tube, cheap low power earplug type headphones and a long piece of wire for antenna...it actually worked too..1965! (Crystal radio plans probably somewhere found on YT.) Aah yes..the good ol' days! Truth be - it's much better these days....so all you kids out there...you're spoiled rotten! Ha ha ha! 😉
Yead for my essays had to rely on library, when i go to library the book i want is already has been borrowed😏
I wasted weeks learning all you say in here, which I could have learned in ~20 minutes. Great video. Please add more tags to it, so you rate higher in search results.
For 30 years I've seen explanations of how to use a transistor and never "gotten" it. Bravo this is spectacular. The best explanation of a bipolar transistor I have ever seen in any medium.
@2:54 Your description of the circuit symbols for NPN vs PNP BJTs is so ridiculously simple and intuitive
@7:00 So THAT'S what hFE is used for with BJTs!
This whole video is so informative it's helped me to make tons of sense of how BJTs work. You, sir, are a genius.
Clear and well-presented. Amazingly, this circuit was pretty much the same as when I started studying electronics back in 1975, including the 2222 transistor! So for you younger students, the techniques outlined in this video will practically never become obsolete. We tend to think that the world is run on low-voltage, low-current technology (e.g. microprocessors, microcontrollers). But at some point real work requires higher voltages and/or higher currents, so studying transistor control circuits, like the one presented here, is very valuable knowledge.
How I wish I had friends as smart as this guy in my circle. I love channels that pass along wisdom to others....thank you, Sir!
So clear. So lucid. This is a great switching transistor 101. Thanks, really appreciate the work you put into this.
One of the best transistor as a switch presentations I’ve seen. Thank you.
Good Tutorial. Thank you for that. Just another thing: You have to consider the power dissipation of the transistor itself, due to the voltage drops across it. taking the numbers (0.2Volts and 56mA), you can say that the transistor dissipates like 11mW of power, which is quite low for that circuit, but if you have a larger current and also a larger voltage drops on the transistor, you could damage your transistor if you don't attach it to a proper heatsink.
Why couldn't I have had you as my electrical theory teacher. What I learned in 21 minutes with you took me weeks with my teacher....and I probably still did not quite digest and assimilate it well enough. Thank you for your tutorials and lectures. You are educating the world.
Watched many video's on the topic, none was ever this clear. Thank you!
Thank you, thank you, thank you, for mentioning the 0.7 volt drop across the base-emitter junction, when calculating the base resistor. I see many people forgetting to subtract that 0.7 volts. When using 5 volts to drive the base, forgetting that 0.7 volt drop across the base-emitter junction will create a 14% error, when calculating the base resistor. That’s more than enough to prevent the transistor from switching properly.
Also, for the beginners, when he talks about the “clamping diode”, it’s worth mentioning that it goes by many different names. You’ll hear terms such as, “kickback diode”, “buck diode”, “flyback diode”, etc. They are just different names, for the same diode. Use a good diode, as well. One of the most popular silicon diodes, which I recommend, is the 1N4007. Actually, the MOST common one is the 1N4001, but it’s rated for much lower voltage. The difference in price, between the 1N4001 and 1N4007 is so negligible, that it’s worth just buying 1N4007’s. That way, you’ll be covered for any voltage that you’re likely to come across. It also provides an extra safety margin. In a “clamping” application, a failed diode will typically fail ‘shorted’, which will burn up your switching transistor, as well. It’s definitely worth spending an extra penny, for the better diode.
1N4007 has higher forward voltage than 1N4001. 1N4007 waste more energy to operate... Same thing happens to higher voltage transister. So not a good idea to choose higher rating voltage than it needs to be.
PS.....Also I have heard word "free wheel diode"
ຮຸ່ງ ພຸ່ງແຣງ So what would be the best way to protect the transistors if picking a higher value diode is not efficient?
@@Asyss_Complex The Fairchild (On Semi) 2014 datasheet for the 1N4001-1N4007 series specifies the same forward voltage of 1.1V at 1.0A for the entire range.
In addition, the energy dissipated in the diode is not a consideration in these sort of applications unless you're trying to switch the solenoid at kilohertz frequencies (!), so it doesn't really matter which diode you use.
Very nice explanation. Super clear and concise primer on transistor basics. I was glad you skipped all the ohms law and such and just got right to the setup and calcs needed to drive your load. All the rest of the blanks can be filled in from innumerable other sources across the net. Excellent job!!!
You are a life saver. Thank you for that explanation, it solved some questions that I had in my mind. It's nice to know why I am doing certain things instead of blindly following equations. Thanks.
I went to school to repair PCBs many years ago but in my profession I wound up doing repairs at the next level. "Through that board away and replace it". This is usually the cheapest and quickest for repairs of most equipment but that takes all the fun out of it. I still enjoy dabbling with semiconductors but time is not on my side. This great video helped me to refresh the details I need for my dabbling. Thanks, Great video!!
As someone who routinely removes protection diodes, I appreciated the detailed explanation of the relay inducance pulse. I may leave a few more diodes in my circuits now :)
Thank you so much. I've spent ages trying to learn this basic theory and you have explained it wonderfully. I now feel I can grab some components and use them to switch real world items from an arduino. Fantastic video!!!
Thanks. Your experience shows and this makes me feel confident about your lecture. As my brother says: in theory practice and theory is the same but in practice it's not.
Very simple, straight-forward explanation. And somehow you managed to predict all the questions I wanted to ask as I was thinking them. Excellent video!
This was the best video I found on biasing a transistor. There were a lot of videos out there that didn't explain what the β quantity actually was.
Good job.
This gave me the understanding I needed to figure out a circuit I was banging my head against. Thank you!
Don't damage the circuit with your hard head.....lol
First year electrical engineer student.
Thanks for this video, I think you are a great tutor.
I have worked in electronics for 35 years, and so wish I had a presentation like yours when I was starting out. I never really understood transistors that well. Good work!
I have spent weeks watching CZcams videos and even trying out the Great Courses plus series on electronics. Your video is hands-down the most educational and clearly explained thing on the internet. Thank you!
It took me years to learn this by myself when i was a young electronic enthusiast. You summarized nicely, and totally understandable. Great job!
See my vedio on transistor ckt design
Best transistor tutorial I've seen yet. Thanks alot!
This is an excellent video! Great job on explaining the thought process and the math behind your decision as well as the practical application of it.
This video is awesome, no one else has been able to answer these questions clearly for me. I also appreciate that you actually included the formulas needed to calculate the resistor needed on the base leg, etc. Great vid, thanks a ton!
Really a great video! Clear and simple!
Thank you!
cos è sta supercazzola? ...hai il dono della sintesi? me la riassumi? :)
La cultura non è per tutti!! 😜
a hahaha....preparati per la stagione venatoria che siamo a brucio vah!!!
Wow, great job on the video. I'm not too good with electronics, having learned strictly with MCU's early on and using digital PWM instead of actual power management. You have nearly tripled my knowledge on transistors and how they can be used, and for that, I thank you.
Same here :)
I've been trying to wrap my head around transistors this whole semester of solid state electronics and motor speed controllers. You are a great teacher, I understand why I let the smoke out now.
Very clear and explanatory, thank you. Never late to watch such educational videos even after a decade. It was brilliant.
Absolutely fantastic tutorial!
REALLY good video. Probably the best transistor video I've watched. Nice job!
I'm pretty sure this is the best introduction to how to practically use transistors and explanation of their essentials of how they work I've ever seen.
I have always wondered about how this worked. Seeing you add the different components to the solution and the calculations were very clear. Thank you
That was wicked awesome man, thanks a bunch.
You are a great teacher! Thank you!
Perfectly done
Just a curious question. Why is your current flow in reverse? Current flows from negative to positive
fernando velasco mathematically it makes no difference which way current flows. Most people use conventional current flow over electron flow
Yes it does but he is talking about CONVENTIONAL CURRENT FLOW where it is imagined that current flows from + to -
I ve deep interest in electronics i want to learn more...
This is a great video. This explains partially why a joule thief works the way it does. The joule thief resembles a Hartley oscillator. I wish I had a teacher like you when I went to TCI in New York.
Great tutorial, thank you. After searching for a while, I finally understand the meanings of things like gain and Hfe, and why a diode is important in a solenoid circuit.
Thanks for the great tutorial. I wish you would have given details about how to choose the appropriate clamping diode. Also a bit about the rol o the capacitor, and how to choose it. Also, it was unclear to me why NPN instead of PNP. I did not understand the justification.
Finally, a way to control a motor requiring 12 V from an Arduino and L293D. :)
Learned more in these few minutes than in the hours I spent on my own to clearly understand these principles. Many thanks and cheers from Florida.
Very good explanation. Just the right amount of information for an introductory of how to use a transistor as a switch.
"Yeah but I live in a voltage world how do I get this solenoid to turn on and off"
Legit LOL'd.
Livin' the voltage life.
Many years ago, I came up with a way to quickly differentiate between NPN and PNP transistors. I look at the emitter arrow, and if the arrow isn’t pointing inwards, its an NPN transistor. NPN = (N)ot (P)ointing i(N)
Try to watch Razavi lectures you won't need hacks to remember that
I learned the difference by just never using PNP *dabs*
''Points the arrow to the B - it's PNP'' is another way
@@ajayrajan8882 mnemonics is not a bad method to reliably revert stuff though
Great tutorial. I know the feeling of blowing things up through a lack of knowledge: I destroyed two "5v" LCD screens instantly, it turned out the backlight was 5V, but the control was 3.3V.
That was one of the best transistor videos I have seen. Practical approach and good examples. Excellent!
Actually they DO make 4.3k resistors and they're part of the E24 series (24 values per decade).
I would always use a MOSFET for power control, and not a BJT. Unless I needed to control the amount of current through the device. BJTs drop voltage and waste power.
Absolutely. Although MOSFETs have to be driven hard(er) for higher voltages - and even in this case, they would require a pull down resistor at least (5V is high enough gate voltage for most cases to driver 12V). It's harder to explain.
A BJT is a perfectly reasonable choice for currents up to 100mA as the voltage drop and power wasted is then negligible. Above that, a logic-level power mosfet is a good choice, and essential if you have a 3.3V microcontroller. Remember that the mosfet will normally cost three times the price of a small-signal BJT.
Glad I ran across your channel. I am an EE working in the field and also work part time as an adjunct professor. You did an outstanding job in simplifying the explanation of a practical situation of component use. I admit that I wish I could make it that simple for my students. I will strive to be better. ;-) Thank you for the challenge.
Probably the single most useful video I have ever found on CZcams. Thanks! Finally I think I actually understand how to use transistors in this context!
Back in 1979 my high school electronics teacher taught us to remember NPN = the arrow "Not Pointing iN".
It's still the best way to remember it.
Hi :)
Great video
Just one question: why did you say in the beginning that the pnp doesn't have a way to limit its base current? Shouldn't a resistor work as in the case of the npn?
Andrei Stefanescu, since the logic input signal varies between 0-5V and the emitter is at +12V, the base current can never reach zero. Thus the PNP device is a poor choice here. On the other hand, if the logic -input- output varied 0-12V it would be acceptable.
@andrei, think opposite. in an npn a + voltage at the base turns it on. in a pnp a + voltage at the base turns it OFF. 12-5=7VDC across the emitter/base juction, because you have + 12vdc at the emitter.
@@avid0g so you would use that if you needed a 12V signal to control a 5V device?
@@renakunisaki
My point was that an open collector logic device with a resistor pulling up to +12 volt would have the correct output. The logic device needs to be rated to handle the +12V. An NPN would also translate, but with inverted logic.
One downside to resistor pull-up is the RC time constant rise waveform.
Just wow. I have never been able to grasp the basics around transistors, yet your video seems to have demystified it to the point I could confidentiality use them in a very simple circuit. Thanks soooo much.
I think I learned more about transistors from this video and a few others on youtube than I have in my senior level college course. Thank you for making this easily understandable and well explained video!
So what do you guys think about biopolar transistor are they getting too old since the mosfet ones got more efficient and popular or is it just me? for all my applications I use FETs and can hardly think about using biopolar yeah FETs are a little more expensive but still the low 'ON' resistance (Efficiency) is well worth it.
"A little more expensive" can add up to a lot more expensive if one is building hundreds of thousands or even millions of widgets, with each widget possibly having many transistors. I would guess most companies simply go with the least expensive option that meets the requirements.
Yeah but the very high efficiency translates in to a more quality product when it comes to power consumption and simplicity anyway mosfets get cheaper and cheaper over time.
True. It would then depend on what the requirements were, and if reaching higher efficiency is more important than reducing costs. In some cases it would be worth it, in other cases, not so much. But either way, you've made me think about it and I will do some more learning about BJTs and MOSFETs so I actually have a clue what I'm talking about lol.
Yeah that would be great!
Michael bjt transistors aren't inferior because they're older they happened to be discovered 1st. Fets are a cousin to tubes which came before that. Tubes still have their place. darpa is still pouring money into tubes. a plain old 3904 bipolar isn't going on the scrap heap any time soon.
Nice video. The 2N2222A handles 800mA, meaning that if the restriction depends only on the transistor, the right resistor would be (5 - 0.7)*100/0.8 = 538 (560 ohms). So, the solenoid would be destroyed but not the transistor!
What about the power loss that occurs between base emitter junction due to low resistance? Cant ignore that either.
right what I was going to say
10, not 100. As a switch, base current should be 1/10th of collector current. Read the datasheet.
@@AlienRelics Can't help think that Ben has been scarred by destroying many transistors when he started out that he errs on the side of minimizing base current. 1K would do the trick.
@@kissingfrogs Perhaps. But beta varies from batch to batch, device to device, temperature, and time. I'd accept 15 or even 20, but 100? That is the rated beta in the active region.
You'll destroy more transistors with excess Vce drop at higher current.
I worked with EE's. I have some electronic background, but not design. I would marvel at my EE throwing together a complex circuit and wished that I had a fraction of this skill. This video is a great first step at understanding design, beyond just following a schematic. Thanks
Just what I needed - Transistors are a simple yet madding concept that pushed me to look for a tutorial to get back to basics. Found exactly what I was looking for!
I've got two bread boards. I can make a ham on rye on one of them.
I tried that once, but the wires kept getting caught in my teeth.
What you didn't cover was how you chose your diode and which one.
electronics.stackexchange.com/questions/110574/how-to-choose-a-flyback-diode-for-a-relay
I've been using npn transistors for a few years and Never fully understood why sometimes they work in my circuits and sometimes they don't. So glad I stumbled on this 9 year old video!! thanks
this is seriously the best lecture I’ve had about BJT on the Internet. Keep up the good work Mr.
in your circuit you need to add resistor between base and ground e.g. 100KOhm to avoid floating base
Good tutorial though
Beboba This tutorial discusses bipolar transistors, which do not have floating bases, and do not need such a resistor. An insulated-gate transistor such as a MOSFET or IGBT have high impedance gates that may need a resistor to tie the gate high or low.
Applied Science Interference from nearest components can easily turn the bipolar transistor on. E.g. if you have high voltage generator.
+Applied Science Can you explain what a floating base, or floating anything is? I see this mentioned a lot when reading about electronics.
+Akfloatable Leaving a pin of an electrical component not connected to anything is considered "floating". This means that the voltage at that pin can change very rapidly if there is nothing to sink or source current. Turn on a digital multimeter to its voltage range, and leave the test leads disconnected. You'll see the voltage floats around. For some components like bipolar junction transistors (BJT), leaving an input floating is not particularly bad because the device requires a fair bit of current to operate, so the pin will remain fairly stready by itself. A MOS component requires almost no current to operate so the slightest bit of charge will cause the pin voltage to change, and turn the MOS on and off very rapidly or partially, which is not good.
+Beboba BJTs are current activated devices (current from base to emitter establishes the current from the collector to emitter.) If the base is floating, there is nothing to induce a contiuous current from the base to the emitter, an electrostatic charge, while a very high voltage, doesn't have enough charge to induce a large enough current to turn a small signal BJT on. FETs have the issue you discuss where they are voltage activated devices (voltage between the gate and source establishes the current from source to drain) and can easily be turned on by stray voltages. All that said, very high gain BJTs (especially darlingtons) can be briefly turned on by small electrostatic charges.
this is what i expect . most of the videos simply explain the low to high but you deeply gone. thanks a lots
When I first started in electronics it took me way too long to understand how transistors work. Wish I had this video when I first started. This pretty much covers everything you'd need to know about using plain BJT NPN transistors for use in DC circuits. Best and most concise explanation I've seen on the subject. Well done!
Excellent video! Sent here by a friend from eevblog and now have a MUCH clearer understanding. Thankyou so much!
Nice job. I was trained as an EE, and in the lab I blew up dozens of 2N2222 transistors. Later, as an "advanced" student, I destroyed a few Op Amps before I got the hang of their biasing. In the late 1970's, a simple NPN transistor was inexpensive - maybe 25 cents at the school lab stock room. Op Amps were much more expensive in the 1970's -- maybe a couple of dollars -- so I learned to read the data sheet carefully before breadboarding those projects.
When in doubt, add a resistor! It's a good motto for any EE student or dabbler in the mysteries of electronics. One of the most valuable circuits a designer should know by heart is the voltage divider. Such a simple circuit, and so many fresh faces in the lab don't know it. Lesson 2, a little more complicated, is using a negative feedback circuit to automatically control current surging at the base and thought the transistor. Always protect your active components! I appreciated your trick to sink stored current around the solenoid, too.
Thanks again. I'm retired and haven't played with electronics in a long time. I've been looking around CZcams for interesting channels. and yours is practical without being pedantic. I'm a new member and will be looking in.
I think i watched hundred of videos on the same subject.
This is the first time that i see someone explaining every single step, all others always take those for granted.
And abole all i appreciated the first part, when he described the several choices (possible components to use). All the designers make tutorials and never clear why they use a particular component among others and indeed they must know the reason (again take that for graanted).
I congratulate and thank you.
I'm only half way through the clip, and I have to say: thank you for teaching me the difference between NPNs and PNPs! Also clears up as to why my electronics project failed, as I was not given the distinction that they are different and as to what the difference is. The irony is, it's simple! I guess the teacher needed a break.
Starting with the age of about 16, most education systems require a bit of own initiative to acquire knowledge on their own on the part of the student (like at least asking questions in case something isn't entirely clear), as that is really considered the most important task of mandatory education, rather than simply conveying knowledge. But it might not be the case where you live, which begs the question, how would that kind of school system prepare people for college or university at all?
I've been reading about transistors for a few days now and this is the first tutorial that actually makes it clear to me, thank you!
I was wondering about PNP and NPN transistors. You explained it in like 40 seconds compared to 30 plus minute videos i've been watching. Your videos are so concise and informative! Subbed!
Excellent video...probably the most clear concise video on the topic I have ever seen! Thank you so much!
This was a perfect lesson. Thanks a million. Exactly what I wanted to get my head around using transistors as switches.
Ben, this is a GREAT transistor tutorial. Very clear and thought out. I use this as a basis for my switching transistor circuit design. Nice Work.
Excellent video. For me this was a great refresher of basic electronics theory I learned about 40 years ago. All valid points and well presented.
omigosh i have been an electronics hacker since i was a kid and i think i've never gotten such a solid grounding of how to work with a transistor. i'm 100% going to use this as a reference on my next project
Hats of to the depth this man goes to for explanation. Amazing.
I learnt alot from this video ,well shown and explained ,and i am 65yrs and still learning ,Wish i had someone like this to teach me in my younger days .Many thanks .
Excellent design exercise. Thanks for taking the time and making a video with the most complete and clear explanation. Best ever!
Your video connected much of what I knew to be deficiencies in my electronics knowledge. Couldn’t believe how much is in this one piece.
Excellent tutorial. Thanks for sharing the very basics of a transistor to be used as a switch. Very nice demonstration.
Just what i needed. I have a design concept, but needed some practical info on sizing components. This was perfect. Thank you.
Great video. Very clear and easy to understand. Exactly what I was looking for.
So simple topic ..... But you inserted a universe of knowledge....
Great explanation.....Great love towards the subject....
Finally... simple topic is where the research starts...
The world should know this.....
Thank you for explaining that so clearly. You answered many questions for me. I don't follow books well and listening to you really helped a lot.
Great tutorial; objective, easy to understand, and covers the important things we need to know. Great !!!
I LOVE these explanation/teaching videos! I always get so much from them. 👍
Super informative video. Thanks so much for all the work. As it turns out, I'm designing a circuit to control an air solenoid, and your lecture helped me so much in the design of the drive section. Thank you!
Thanks for that lesson. I was a mere lad when most audio electronics were tube devices. And that includes TVs. But today i enjoyed upgrading my knowledge with transistors.
very clear - excellent. This is the first vid about transistor calculations that I actually understood all the way through. So many jump over a detail, especially that bit about the 0.7V drop and I think I'm missing something when actually it as the presenter who missed something. This was so very clear - thank you.
Ben Krasnow, you are a great teacher :-) Thank you for these explanaitions!
I am ecstatic about how great this video is. Seriously, thank you for making this. You explained so many things I have been wondering about.
Thanks man...your ability to explain complex system is awesome. It is fortunate for me that you post these or I'd be lost.
Thank you.
I have no business being here, however I stumbled upon it and watched it all the way through and I think i learned a thing or two along the way. You're a natural teacher, thanks s`much.