the best thing about this guys videos is that he dosent waste time at the begining of the video, he just gets right into it

that unedited part at 7:38, pure chill.

Your paper moving skills are off the chart

0:00 - basic transistor 2:25 - inverter 4:14 - and gate 6:08 - or gate 7:38 - *NO* gate😀 8:29 - xor gate 11:50 - whole list

Till date the best explanation of logic gates using transistors. I wish I had got this 18 years back

What sets your videos apart from others is that you really show all the small steps in between and really break it down excellently. Highly appreciated, excellent work. And, to be honest, this way it is much easier to understand than with any fancy digital presentations.

Excellent presentation/demonstration to easily understand logic gates

I barely turned 13 years old and this really helped me clear things on how to make gates and what the hell a transistor is. Thank you so much. please continue this work

If you are still not a professor please... Became It! Best lesson of transistor i ever heard!

Resistors used on base: 1k Resistors used on collectors: 100 ohm Transistor model:2N2222 Led: green at 1.2 volt You can use white led at 3 volt The modern silicium transistors have an incredible dynamic range. When OFF, the collector/emittor appear like a very high resistor of more than 50 Meg ohm. When ON, the same two pins act like a low value resistor of about 0.1 ohm. The expression 'semi conductor" is misleading. The material conduct as good as the best metal, copper, in the ON state and act as an excellent insulator when off. The first transistor made with germanium were not as good. In the off state, there was a current leaking from collector to emitter equivalent to about 10 k. When the transistor was warm, it leaked like if it was a 1 K resistor. The OFF state was not that strong neither, cold or hot. About the NOT gate: The explanation is as follow: When the transistor conduct, it is able to act like a very low shunt resistor of approximately 0.1 ohm. It can force the voltage to go as low as 0.2 volt, which is much lower than the usual voltage drop of a diode, 0.7 volt. If you take a voltmeter, you will measure: Emitter = 0 volt Base = 0.7 volt Collector = 0.2 volt The base/emitter pins of a transistor are simply a diode with the usual voltge drop of 0.7 volt. A green LED need about 1.0 volt to turn ON. If you apply 0.8 volt, you get no light at all, not even a feint glow. So, since the transistor can lower the voltage to 0.2 volt, the LED is off. However, if you replaced the LED by an incandescent light bulb, you would see a feint red glow when the logic state is "0".

And that, my friends, is how computers work! Now that I know this, my next challenge is how to get 1,5 billion transistors into a cellphone... Could be a bit tricky.... Jokes aside, as a retired Civil Engineer dabbling for the first time in electronics as a new hobby, this video and style of teaching cannot be overpraised. Well done Sir! Much appreciated!

15 years experience as a control systems engineer ( specifically PLC's)and now I finally get it ...Ty!!!

Finally a video where I could clearly understand what transistors actually do and why are they so important. Thank you!

I took a computer hardware architecture class in college and we briefly discussed and/or/not gates which I kinda got - your explanation totally cleared it up for me. I definitely had an A-HA! moment watching this video.

Discovering your channel is the best thing that has happened to me in a long time. As an EE student who just got started on learning basic digital logic and circuit design, this has my mind blown. Thank you for your videos!

dude your videos are perfect. You show the schematics, boolean truth tables, and physical breadboards to prove it all right there.

I wonder why isn't this channel popular, This channel deserve more than this

This is the simplest and most intuitive explanation of a transistor I have ever seen. Very good work.

Just came across this vid by complete accident. Absolutely brilliant. I’m in my 50’s now and learnt logic gates almost 40yrs ago during computer studies BUT was never shown how to use them in practise with electronics so I never made the connection between 0 and 5v etc. Electronics ended up as a bit of a dead end subject for me and I went in a completely different occupational direction. I’m now retired and really enjoying getting back into electronics and have thought about trying to work these logic gates out for myself. You’ve not only beaten me to it but explained it really well. Thanks very much! 👍🙂🏴󠁧󠁢󠁷󠁬󠁳󠁿

In the military I worked on 60's era launch control system. All of the logic was built like this on postage stamp sized boards.

About 50 years ago - Vietnam War era. We had several books of circuit diagrams and others with logic diagrams built with basic gates like these. Hawk Missile guidance control systems. All "Top Secret" back then. It would all fit on a grain of sand now. But back then it was big stuff - actually useful when we could keep it running. Lots of breakdowns. That's where I came in. (smile). After service, I used to keep a small breadboard of logic circuits on my desk to remind me of those times. I'm 75 years old now - still breathing.

I loved the silence around 8 minutes. It felt as though he was giving us time for it to sink in. Brilliant!

I love these videos. Ben has a special talent for being able to speak very quick and clearly at the same time. It's like speed reading interesting content

I’ve been trying to understand transistors and logic gates for months. This video just did it in 13 minutes. Great video!

For those who are interested, his explanation of how a transistor works is based on conventional current; which is the reverse of the actual electron current. You can imagine the electrons building up on the emitter with nowhere to go because of the depletion zone between the emitter and collector. when the circuit between the base and the positive terminal of the power source is closed, the electrons move from the emitter through the base to the positive terminal and in the process are also able to cross the depletion zone to the collector.

I just learned what a basic transistor is in just 2 minutes, like veryyyyyy clear and concise, compared to when I was in out online class.

these premade neat models are the key to completely understanding this . even if i myself dont have such circuit made for me as i study , i see it working as it is intended and the circuit diagram confirms this . so great . your effort is phenomenal . thanking you from the bottom of my heart . thanks

Almost 5 years after this video was uploaded I stumble upon it during the process of trying to learn about transistors, microprocessors and how computers work...and this video manages to get this basic gate info across to me even better than the fabled book "But How Do It Know?" which had me glassy-eyed by page 36! Well done, sir!

This is more helpful than my stupid college lecture.

6 years late, but this video really helped me understand how transistors work in logic gates! Thank you so much :)

This is such a fantastic, concise demonstration of the concept of logic gates using transistors! Thanks so much, Ben!

this is actually called RTL logic it was shortly replaced by TTL gates because of the high current consumption!

I love how consice he is, his understanding, and his presentation, is this guy a professional teacher or something?

Flashback to building these in an undergrad Computer Logic course I attended back in 1985... Thanks for sharing! I enjoyed it!

I was finally able to make the XOR gate through your video. Such an elegant design. Thank you.

I studied all this at the University (I am an electronic engineer), but I am still really enjoying watching these videos of yours because you explain very clearly. Better than many of my professors of the times. Congrats! :)

THANK GOD, I FINALLY GET IT! I've been trying to learn this for a few months already, you showing the schematics as well as demonstrating it made it click for me!

Can you not make an AND gate with just one transistor?

You sir are my saviour. Finally someone EXPLAINED how this thing really works instead of giving me false, useless and over"simplified" examples of how the gates work

He’s so good at explaining I’m only 11 and I understand

I don't think you know just how GOOD this video is, as I been thinking about all the circuits I could do, and I can just see it.It was just an excellent way to teach it. I have been thinking about this for hours. I am very good at electronics and you just did a super job. You could change some kids life, by just waking them up, making them think, opening a whole new world! WELL DONE!!

I've been looking for someone to explain these gates forever - this is so helpful.

Was having trouble on finding a video on the internals of logic gates and you nailed it. This made perfect sense. Thank you!

You got a pretty long silent part from 7:40 - 8:17 I think you forgot to make a cut ;)

Your video is just amazing. The explaination so crystal clear. Thanks as it helped me built my physics project on logic gates.

Simple, clean, well structured ... It's just awesome, thank you !

I wish you taught me my first year of electrical engineering school 🙂 So much time spent working formulas calculating all kinds of stuff and zero time spent just telling you how the components work and what you could do with them....love the practical explanation!

What you do is exactly what i want to learn, i will definitely pay on patreon if i see you are consistent (it is my first video from you)

I've seen only two of your videos, and it feels like a complete ILLUMINATION !! Now I understand how logic gates are made with transistors, the way they look physically, and how they are inside the DIP IC's ... thank you SO much. I had lost the interest on the subject but it rose again now that I'm watching your videos because now I understand. Your videos are clean, brief, on point and very detailed. THANK God you are making these videos! YOU HAVE the talent of teaching, God BLESS YOU MAN!! for real!!

Your videos are really inspiring and motivating. Thanks for all your effort!

Man, this was just so concise and exactly what I needed. Couldn't find anything else like it for this specific topic 👍

I don’t have the cash or time right now, but I’m going to buy and build all of your kits, this is addicting

Everything up till this video, we covered in my Digital Electronics class, but this is something that was NOT covered, and it a very important in understanding how all the gates work. PLTW has failed me as a student, or the teacher did not follow the course right. Either way, it's taken me 5 years to finally learn the truth on how these work. Thank you education system, you sure did me a great service.

What makes this so dope is you include both analogue and digital circuits at the same time for a complete picture of how everything works with no deception or gaslighting involved. Often digital logic is taught by saying 'you don't need to know the implementation' or 'it's not my job to explain analogue circuits.' And analogue circuits are taught by saying 'it's not my job to build logic gates, it's to show the science of transistors.' etc. So people end up with a huge hole in understanding that is exactly this video. You do it the right way, providing the analogue circuit as the primary foundation with its truth table as a tertiary feature.

By far the best explanation of how transistors work I've ever seen. I wish I could 'like' it more than once. The XOR gate in particular was a eureka moment for me. Thank you.

I'm pretty sure that I've learned more from you about electronics than both my electronics and microprocessor class in college combined! You're very good at explaining how it all works! Keep it up!

So far this is the best video explaining logic gates. I appreciate the explanation, the schematics, as well as that you have the gates built on a breadboard, so the users can pause the video and try to rebuild it by themselves. Thank you! EDIT: I think you had something wrong with the OR gate, mine didn't work that smooth, didn't know why. I worked it over with another video and it works though. While these gates are good for demonstration purposes, the wiring could be optimized by linking the transistors without jumpers.

Thank you. For a newbie like me, these videos are gold.

I watched your videos regarding networks before. How happy I was to find your videos once again for another topics I'm interested in

Finally, a minimal TTL diagram that really works! Thank you!

my mind is truly blown on so many levels. Man I love this stuff so much.

I have to leave a comment here. I have been looking for an intuitive explanation on how XOR gate works at circuit level for very long time as I have not electronics background. I finally get it today. The sense of understanding is great. Thank you Ben.

one of my favorite editors. good fx

Thank you. I'm using this information to totally rewire my computer.

I had a difficult time with transistors, cuz I'm a beginner. After watching your video, I have at least vaguely understood them.

I like your easy-to-get explanations of transistors as logic gates. Thank you.

Certainly one of the more accessible explanations suited for younger learners Great job!

The best science videos I've found

Thank you. Great lesson how the logic works behind the scenes.

In my digital electronics class we learned how to build modules all the way up to a microcontroller starting just from logic gates (although we did it through coding an FPGA, not with individual gate chips on breadboards), but for some reason we skipped the initial step of building gates from transistors. Not sure why when it obviously only takes 15 minutes to explain. Thank you for filling that gap in my knowledge.

Excellent on building Logic Gates with NPN BJTs. Very clear and precise. Thank you!

I was laying in bed, thinking about precisely this, and i find it on my raccomandation 5 minutes after. Damn

bravo! great explanation!

Just watched many intro to logic gate videos.....Logic concepts are as simple as they can be but their purpose didn't click until I saw a physical representation of them like you've done here. Thank you!

Amazingly simple and conclusive reference video. Love the content!!

Incredible! This is the knowledge gap I've had when it comes to ICT.

It was at that moment that I actually learned how a computer really works!

A most beautiful and complete explanation - thank you.

I love your channel, it's the best resource as an electronics refresher course.

A minimal transistor-count Toggle Flip Flop would be very interesting !

YOU ARE THE BEST! Vefy nice EXPLANATION

i ran out of OR gate ics and you really helped me, i needed it, thank you ❤️

Best explanation of how to use transistors to make logic gates on UKposts.

+Ben Eater Great video!! Can you provide some specs on the transistors and resistors you've used in this video? My dad and I tried making your circuits and we couldn't figure out the parts you used from the video.

Second schematic uses voltage devider. There is still voltage across diode, just not enough to light shit up.

Master Ben, your a true guru in these videos man, I'm able to expand my projects after your straight forward teachings . Bless you sir

What I've noticed in the XOR gate diagram that you made is that it's two gates that work together. An OR gate and an AND gate. The OR gate is the primary gate while the AND gate is more of a secondary. The AND gate just adds more functionality to the OR gate.

For the XOR logic gate, it seems to me the +5V supply (thus the resistor also) at the collector of the BJT between the AND and OR gate units is not needed. Also the resistor between the AND gate unit and the middle BJT seems to be unnecessary for logic operation. Can you confirm?

I wasn't much good at electronics at school. If I'd had Ben Eater as a teacher, things might have been very different.

Amazing explanations! If you are a professor, your students must thank God every day to have you as their professor.

simply sweet and easy for not, and, or gate demonstration. Thank you.

Hello, thanks for the video. I have a question in mind about the circuit at 3:20. So, we're saying that there is no voltage difference between the two sides of the transistor, and I guess that's because the resistance of the transistor is negligibly small. But does electricity still flow through the LED, albeit with no effect visible such as light? And does that, in a larger scale like in CPUs where there are many transistors, affect the system?

One of the best videos on the web. But I keep wondering why everybody in every video and tutorial keeps repeating that when transistor is on all the all current flows through it and because of that the potential difference between collector and emitter drops to 0, effectively meaning that both of LED's legs are connected to positive side. That's not correct, transistor is not a superconductor, it still has a resistance when it's on, current does still flow through LED, the reason why LED turns off is because current becomes way way too small which is not enough to light up the LED.

Seriously Ben: You should teach this professinally. You can explain very well and have a deep understanding of electronics. Greatest respects to you, Carl.

What i didn't get in school in several hours, I get it here in few minutes, thank you very much! 😊

I have an idea for the XOR gate. To save power, you should put a transistor in series with the two transistors that basically make a NAND gate. Then, connect the base of that transistor directly to both inputs. This ensures that if A or B is on, the circuit is on, but if neither A nor B is on, no current flows at all.

I loved electronics as a child, I was always disassembling broken electronic for components, making things, but never had mentor or support and this was pre internet (too poor to buy a computer anyway) pre maker space days so outside local library I was out of luck. Now as an adult with young children of my own I'm picking back up these hobbies in the hopes that if my son's so choose, I can perhaps help them I whatever interests of endeavours they choose. Guess thats my long winded way of thanks for making these videos.

Is the inverter you made at around 4:00 functionally equivalent to a pnp transistor, or is there a difference in behavior between the two? I know the operating principle is different, since the pnp acts simply as an on-off switch, and the inverter functions as a low resistance path opening compared to another one, but does that make them behave any differently?

This was really brilliant and simple. I am thankful, guys like you are on the internet

I appreciate you so much thank you!