Guest Video: Bob DuHamel - How Opamp Virtual Grounds Work

[@EEVblog]

UPDATE: A slightly corrected version is here: kzbin.info/www/bejne/oZ6ZlZiipqxgesU

[@momomo393]

wow such a great demonstration! this is the best explanation of the inverting op amp ive ever seen on youtube

[@rbm0307]

+1 @Jordan Schnabel. It is the pedagogical skills of the presenter that can make or break a lecture. There are many people who understand these concepts themselves but very few of those with the skills Bob demonstrates to communicate those concepts in a concise, understandable and entertaining/captivating manner.

[@rostlaur]

The sign of mastering a field is seen when the person can put theory into words that will captivate an audience of any age and level of experience. You get an absolute 10 from me, I wish I could have been a student of yours 40 years ago when I started in electronics.

[@6alecapristrudel]

There it is finally. The most intuitive way to explain inverting opamps.

[@richfiles]

Let this be the yardstick by which to measure all op-amp explanations... and to measure op-amp voltages on diagrams. :P

[@UpcycleElectronics]

Yeah, anyone trying to understand op amps really needs a practical intuitive understanding first before trying to understand the math. It can also help to play with some crude discreet transistor based op amp circuits to help gain an understanding of what is happening on a fundamental level. This will allow you to probe other parts of the circuit or experiment with JFETs/MOSFETs/Darlington configurations. It's a great excuse to create a sacrificial offering to the Engineerapagan Magic Smoke gods. Then learn KVL as it relates to op amps....Still wrapping my head around that one myself in practice.

[@tav9755]

Bob, you are an excellent teacher. It is a rare gift and you have it.

[@3deeguy]

The best tutorial on opamps I've ever seen.

[@microteche]

What a great bloke who is willing to graffiti his garden shed in the pursuit of educating complete strangers, thank you Bob.

[@splitzzzzz]

Prolly whiteboard marker :)

[@galfisk]

Peter Whitney I'm guessing whiteshed marker

[@alimmi9]

Everyone should have a huge coordinate system permanently drawn to their garden shed :D You never know when you need it..

[@apexmike849]

+Adrian L ...Calibrating shed...

[@mearslab]

This is the best explanation for how opamps work, thank you!

[@ManishYadav-gx8ce]

I don't own a credit card to support on patreon. So, I disabled my adblocker, refreshed and intentionally clicked the ad on your video to show my support. Your videos have really helped alot.

[@thecakeredux]

My eyes involuntarily widened as my brain wrapped itself around the concept of how OpAmps work. This was exactly what I needed to finally understand this. Thanks a lot.

[@stevebliss6056]

Some might find the Op-Amp very intuitive and assume everyone else does, but clearly that is not true. Although I am in the former camp, I absolutely love the brilliantly clear way you explained it. Really nice Bob :)

[@theoneandonlyyoko]

I love this videos from the kid yesterday to this electronics veteran , it just shows how the electronics community belongs to all of us and there is no age to start learning and there should be never an age to stop learning,

[@theoneandonlyyoko]

Okurka haha sorry, January 11 I mean, tanner :p

[@trickedouttech321]

Best operational description ever, on VG-OP Amp for that fact best ever on any voltage compensation regulating amplifying component. This was great even for those that do have a good understanding of the function of a VG circuited OP Amp. Feel free to create more content. With great understandable content like this. If you not already, you could become a heavy hitter in the electronic educational YT world. For me personally, I had a good understanding of how the VG worked understanding it was not a true zero and that input and output fluctuated to maintain virtual (0) volts. However, your demonstration truly took my knowledge on this topic and created a deeper understanding that could also be visualized. That makes it unforgettable. Great video!

[@Factory400]

Nice work Bob! You really nailed it on this video. This topic is so hard to explain.

[@clems6989]

Great job Bob. That's the most intuitive description I've ever seen of off amp

[@softdorothy]

I like it when someone takes a novel approach to explaining a concept. You explained several concepts this way and I grokked it all. Excellent.

[@ZacDoesCoolStuff]

Wow, I learned more about OpAmps in this short video than I did in 3 years of university, what a great demo.

[@MrBroseph19]

Really hope Bob can get RSD Academy back on youtube!

[@formbi]

it's back under the name Vocademy

[@LackoPataj]

I am an engineer student at 6th semester, have not seen such cute opamp so far^^ thx Dave, subscribed :D

[@Electroblud]

That is actually the best explanation for Op-Amp circuits I have ever heard. Very nice!

[@Itzpugs]

Absolutely the best explanation of something that yet still blows over my head.

[@gnather]

I very rarely post a comment ,because I am a raw beginner even at my advanced age. But This video helped me truly understand what was going on in am Op-amp. Dave your explanation was great but I got lost because my fundamentals are laking this was a very easy to understand video and I an now a subscriber to Mr. DuHamel's channel. Thanks for turning me on to him. I will go back now and watch your explanation again with enlightenment..

[@michalXKX]

Dave you did it!!! 500k Subscribers!!! Congratulations and my best wishes for you! You are making a history here.

[@amicklich6729]

Bob, you are obviously a teacher! Well done :)

[@MrTaz6552]

Brilliant! Best explanation ever!

[@DrakkarCalethiel]

Thank you for cleaning me up! Never understood this one 100%, it's actually pretty simple when you understand it.

[@thegame4027]

Well, thats how it always works. If you understand it, it's simple.

[@GLPRAGMA]

Great Explanation!! The best practical demonstration I ever had on KZbin. Great Job! I wish you could release another video, diving deep in the internals of a real OpAmp!!

[@alimmi9]

Is BobCAD a competing product to DaveCAD? At least it runs on Gardenshed OS, so thats innovative..

[@Weldod909]

My god, the best explanation I saw, many thanks, I'll have a very good explanation for my students now !

[@ddcreativestudio7602]

Excellent explanation! Together with Dave's video, make OpAmps easier to understand! Thanks for this. :-)

[@hrnekbezucha]

Nice way to clear that out. Voltage is just the difference between any two points. And the relationship of input and feedback resistor as a bonus.

[@Anthony-lr4bk]

By far the best explanation ive ever heard!

[@migsvensurfing6310]

Awesome demonstration. I love opamps, so much can so easily be done with them.

[@isoguy.]

Really detailed presenyation, all tutotials should be like this one. Thanks

[@AdamTheAd-vanc3d]

Excellent. So easy to grasp when you can actually visualize whats happening in a op amp circuit. I never quite grasped the see saw effect until now . Great educational share .

[@hughaskew6550]

This is a very clear explanation. Sometimes visuals really do make the difference (and patience doesn't hurt either!)

[@irgski]

Lovely assistant! Thanks Bob. Great visual explanation of the “virtual” subject. My confusion was what happens with an op amp that uses a unipolar power supply like 5V and you kindly explained that as well!

[@falxonPSN]

Holy ****!!! It's so simple! This is the first time I really "got it". Amazing idea.

[@micronetwork]

Wow! Bob I'm all in! What a teacher you are. :-)

[@Sailesh004]

Why on green Earth I find this video this much lately. Amazing demonstration 🤩

[@Steve_be]

What a brillient way to show hove the op amp works.. I wish it had been that easy when I learnt about it ..

[@samuellourenco1050]

Very complete and thorough explanation! However, an op-amp only tries to compensate the differential voltage at its inputs with the output only if there is negative feedback. This is valid for inverting and non-inverting amplifiers alike. I don't think you mentioned that detail, and it is a very important one. Anyway, this is an excellent video, and thumbs up!

[@apexmike849]

I think he was trying to leave out too many things that would amount to, "except in the case of..", which would re-confuse a lot of people.

[@samuellourenco1050]

This is not an "except in case of" example, but rather a "only happens in case of". He only had to mention that the op-amp has to have negative feedback. But I do agree that it is a detail, although an important one.

[@flymypg]

Nicely done! I particularly enjoy seeing mechanical (geometrical) analogies used to illustrate simple-but-confusing electrical/electronic concepts. Of course, this must be understood as an illustration, not a definition or explanation. It's still an analogy, though an especially good one, since even the (simplified) math works in both domains.

[@uwezimmermann5427]

I really like your way to explain the feedback! It is actually a crucial point and I will come back to your way when this topic comes up again with my students this fall.

[@CrucialMuzic]

Wow where were you back in my electronics days? That was explained very well, thank you!

[@xfran70]

Undoubtedly the best way to teach. Great!

[@BC3012]

That was outstanding 👏👏

[@alimmi9]

The representation with your wife (as I suppose) as the op-amp is very lovely! :) Thanks for the great video!

[@cdnsoundguy]

Great video.....explained a complex subject very simply. Richard Feynman would be happy.

[@juanvarela4006]

Robert, this is my first KZbin comment ever (and subscription to a channel). I found this awesome video by chance via EEVBlog and after watching it I felt you deserve the feedback. I think you used a very creative way to explain OPAMP's behaviour which makes it very easy to understand. I've also found you have very good cadence and clear speech (english is not my native language) which made me even easier to follow. I can't wait to dig in your channel to find this kind of "treasures".

[@spencermayang2306]

It makes sense now. Thank you for demonstration

[@fastlingo]

Nice, intuitive. It's actually a voltage divider with two variable voltage sources at the ends, the opamp source trying to keep the voltage in the middle at a certain level.

[@bjarkeistruppedersen8213]

You take something that is complicated, and make it really easy to understand. Not an easy thing to do 🙂

[@brainfornothing]

Good explanation ! Thanks a lot to you and your lovelly assistant, Cheers from the south of Spain !

[@1978SOOTY]

Wow, great explanation! I honestly don't think I've ever heard it explained so well, this needs to be shown in our tech schools for a better reference. Thanks to Dave @ EEV, you have another sub.

[@1978SOOTY]

And congratulations on the 500K!

[@qzwxecrv0192837465]

wow. so simple in such a short amount of time. thank you so much. If you have more videos or contributions sir, would love to see them.

[@Drew-Dastardly]

Great video, Bob! I don't know how you persuaded your daughter to get involved but she did a fine job too!

[@jsleeio]

Ace! Thanks Bob (and assistant!), that was great.

[@razeenrizwan3082]

Superb explanation . I understood clearly about the virtual ground. Thanks a lot.

[@Lincento53]

I wish i could have wached this video before my exam few days ago, would have nailed "what is virtual ground in op amp"

[@yoramstein]

Make an habbit to consult Yo8uTube before exams :-)

[@v.kritin]

Thank You, sir. This is the best explanation ever. Great demonstration. I had hard time understanding the concept during my college.

[@MarkGovier]

Excellent explanation but the reason the voltage at the inverting input remains zero is due to the fact that the currents reaching that node through the two resistors are equal but opposite. I think current should always be mentioned.

[@billigerfusel]

Already had subscribed to him. That guy is brilliant.

[@electronicsNmore]

Very good video. Congratulations on the 500K! I know it took a while, but you did it. :-)

[@ShinyPennyYay]

Great explanation Bob! Probably the clearest one I've seen.

[@vencibushy]

A brilliant explanation. So simple and elegant!

[@michaelhawthorne8696]

That was a well thought out explanation, thanks for that.

[@bobel659]

Great explanation Bob! I've subscribed and am looking forward to viewing your other videos (and learning more too!). One of the best guest videos so far Dave! Bob

[@grebz]

What a fantastic explanation, nice work.

[@felixar90]

This explanation was one of the best I ever heard. I'd love to show it to my classmates but they don't speak English :/

[@jboy6944]

Excellent demonstration!!!

[@MrDoneboy]

Thanks for this, Dave. Bob is a treasure, who got screwed by yt!

[@ultravidz]

What an epic educator and communicator. Just subscribed to him!

[@IvanIvan1974]

This is a very vivid explanation.

[@ullassasvihallimath9161]

Wonderful demonstration 😄

[@jcobnl]

Great explanation. I wish i had a teacher back in the days at school who could explain opamps like this, it would be so much easier...

[@Pathgriho]

A nice understandable explanation of virtual grounding ❤

[@tl1024]

Sorry Dave, this might be the best 'blog video yet. (With the exception of "unboxing stuff you sent"). Hope you don't get a complex. Best guest nerd video. But, loved '70s Dave, C64 winning! Ground is what you make it!

[@stuartthegrant]

Very succinctly explained, the output is always inverted.

[@JWH3]

I could have used that fulcrum example a long time ago. Great expansion for beginners.

[@Speglritz]

Lovely demonstration!

[@ee6lpzfzj023]

Brilliant!

[@LJ45Chimera]

Fantastic explanation. Thanks Bob

[@peterschmidt9942]

Great explanation Bob.

[@danielbright919]

Brilliant video. Explains it so well!

[@georgegherghinescu]

Best one so far Dave!

[@fizzicist7678]

very creative demonstration

[@utab1987]

Great job! Wonderful analogy.

[@paulrautenbach]

Nice intuitive explanation - thanks.

[@krishna34674]

Super excellent and clear explanation !

[@thekaduu]

Hats of to Mr DuHamel!

[@thekaduu]

Older Afrotechmods... Minus the humor, I guess.

[@UncleSteveFishing]

Now I understand it! Thank you.

[@irawarnaca8133]

Great video, loved the demonstration!

[@ollieb9875]

Thank you for this, very well done.

[@7head7metal7]

Great explanation! And a very charming one, too :)

[@BMRStudio]

Awesome! I saw something similar explanations with gears, lifters, ropes and pulleys when I was kid :)

[@dentakuweb]

That was great Bob.

[@Hasitier]

Great explanation. You have one subscriber more Bob.

[@brianwalters9768]

I believe an easier way to understand the virtual earth concept is to look at the Op Amp open loop gain. The open loop voltage gain Av = Vout/Vin is extremely large, typically 100,000 to 200,000, therefore the voltage between the inverting and non inverting inputs is very small. If the non inverting input is tied to ground, then the inverting input voltage is so small it is said to be at virtual earth potential. The input signal of course does not disappear at the virtual earth, it is 100,000 times smaller than the output voltage. Near as damn it to ground.

[@mikeall7012]

I wish I would have had explanations like this, when I started taking electronics in engineering school!