Classic Circuits You Should Know: Voltage Follower

[@learnelectronics]

Sneak ol' KZbin switched the mid-roll ads on in this video after I disabled them. I turned them off again. Im sorry for the inconvenience.

[@Zzzzzzzzz678]

Much more respect to you bro.

[@gerrywoody4301]

I had a stroke it took from me the work in electronics I loved I am relearning my trade as a retirement hobby your vids make it so easy thanks paul

[@nabeelahsan504]

Loving the "Classic Circuits You should know" series!!! Great work!!

[@CoolDudeClem]

I made a volatage follower circuit once to improove the quality of a cheap record player that had ceramic cartridge, by putting one of these between the cartridge and the amplifier, it dramatically increased the quality. it went from tinny and shrill with no bass, to sounding amazing!

[@Henry-yq3um]

Best video demonstrating not only the principle of Voltage Followers, but also the REASON to use it! Thank you!

[@stevetobias4890]

I love this series of circuits, every one of them has been a teaching video. I am fairly fresh into the circuit design side things. I appreciate the time you put into these videos and send you peace from down under in Oz. Thank you Paul, till next time mate.

[@stevetobias4890]

All these classic circuits should be compiled together into a book or a downloadable PDF. I with so many others would be getting a hold of thîs book or PDF.

[@thematey3592]

Thank you, I actually understand why these things are used in circuits now. Excellent teacher.

[@mikeoliver3254]

I love it, I use this circuit to protect ic’s that I don’t want to push current through. Great video Paul as always.

[@erik1514]

Thanks for the great explanation. I finally understand how this circuit works.

[@SodaKillz12]

So how do you solve the issue of the voltage dropping at the output of the follower due to the load? Is that something you have to live with? I imagine not..

[@Apollo-p1l]

Isnt using a current source in the sim kind of defeating the object of the exercise? Its gonna supply current regardless of load anyway which makes it low impedance? I know Im nitpicking though. Good video and explanation. PS. i think you should have a resistor inline with that zener.

[@teodulosoriano513]

Does not putting a current limiting resistor in series with zener is advisable? Am i missing something? and it would be nice if we see it in bread board and probe things out in multimeter or oscilloscope (I mean you can do what you want thats just an suggestion) but love this channel commenting for the algorithm 😁

[@andrewdoherty737]

Zener goes bang!!

[@Real46]

Most surely! It's hard to understand how he could make such an elementary mistake. He would either burn the Zener or if it had very elevated power, the power supply would burn. I believe the simulation worked because he used a current supply instead of a battery.

[@TheEmbeddedHobbyist]

What's one little resistor going to add to the reliability of the circuit. You just need a very high power zener. :)

[@teodulosoriano513]

@@TheEmbeddedHobbyist why buy one if one little resistor can solve the problem its there to limit the current that said in the datasheet of the zener

[@TheEmbeddedHobbyist]

@@teodulosoriano513 Hi, you need a series resistor to limit the current to less than the power rating of the zener. so a 400mw 5V zener would need the current limited to less than 80mA. normally if using it as a voltage reference you would set the current to a bit above where it starts to zener! and the voltage stabilises. I was joking about not needing a resistor.

[@deankq4adj125]

Don't worry about the ads, another great teaching video. Love learning these classic circuits.

[@warrenking1815]

Paul you should mention the OP amp offset voltage, not to confuse anyone but to ensure that the output is exact as some will want.

[@AbdulRaw]

how do i determine the op amp power supplies (+Vcc, -Vee) if we are targeting the linear region of the amplifier?

[@g_wimsluis6508]

Hi Paul, I mis a resistor between the 12 volt and the zener diode! Nice video's you make. Greetings Wim.

[@learnelectronics]

The Zener is drawing nano amps.

[@elandje]

@@learnelectronics That just isn't true! Look at you own example in the simulation, you have a current source of 1A, the two resistors of 10k in series draw 5V/20k is 250uA, so where does the rest of the 1A go? Through the 5V zener...

[@tookthe5th182]

@@elandje I see a smoked Zener in this example also....

[@dinoden1231]

@@elandje Not only that, but how is he getting 2.5v from the divider? It's across the 12v. Should be 6v! I don't know about this guy. Be careful learning from this guy. Don't want to talk bad, but a lot of his stuff is wrong.

[@vladuzz7]

@@dinoden1231 because it is zener diode...

[@melplishka5978]

Which opamp u using bud.can I use a lm741 .

[@xila8861]

How the bulb would work when it needs 4v to turn on and being feed 1v ? or is that its maximum ? Sorry I am a noob at this kind of stuff.

[@MarioRodriguez-gr8wc]

So even though the currents are similar, when you mean that the output has a high current, you are talking about the gain of 41 mA? Thanks for the help.

[@vdubjunkie]

I really appreciate these videos and you taking the time. To the best of my ability, I feel like I followed the explanation. I just don't know why having high impedance on one side, and low on the other is desirable. Maybe I just need to study impedance to understand. Anyway, really nice videos for a guy trying to begin to learn circuits!

[@Electronzap]

My favorite circuit fragment :)

[@paulkibedy5460]

how can I get that computer electronic software,the one you use in video,how to use it and why you need it.

[@weerobot]

This was Great Video, never seen a Buffer presented So Clearly...

[@alexandrefernandes6286]

Man, your videos are reaaally good!!

[@sto2779]

That was an excellent explanation of an opamp used as a “buffer”/“voltage follower”. Thanks!

[@learnelectronics]

Thank you for taking the time to comment, I appreciate your support. I'm glad you enjoyed the video.

[@MrDunk66]

Thanks Dude 👍🏾👍👍🏾👍👍🏾👍 Why no series resistor for the Zener?

[@TonyLing]

I was thinking exactly the same thing

[@teodulosoriano513]

When this schematic is build in bread Board can the magic smoke escape?

[@tinkeringwithelectronics]

I work on old radios. Would this work to buffer my oscilloscopes probe from say the RF or oscillator section so I can get a read?

[@worstuserever]

Very helpful, and provoking my curiosity about methods of voltage regulation in general. If I can get hold of suitable parts I'd like to breadboard something like this and take some measurements.

[@electronic7979]

Helpful information

[@baijianwei888]

what is the purpose oF the voltage divider?

[@EsotericArctos]

This is fascinating stuff, though I would be careful with saying "isolated" as technically and also electrically the two sides of the circuit are not isolated from each other when using an op amp. To isolate, you would need something like an opto-coupler. I know I am being a bit pedantic, but I feel it is important for people, especially newbies, to know a buffer does not equal electrical isolation. Other than that little bit of pedanticism, I love watching your videos. You always have interesting facts and this is a great resource for people just starting in electronics.

[@simonyoungglostog]

Could you do this with a transistor?

[@fouazhdib6813]

i love your lessons

[@eebaker699]

Great classic circuits video as always. Makes it easy to understand. Like the way you use multisim. Thank you for sharing.😁

[@learnelectronics]

Glad you liked it

[@20thcenturyboy85]

Great Series...so easy to learn from you! THANKS!

[@skf957]

Hi - is anyone able to explain why this arrangement is preferable to getting a transistor to switch the higher current?

[@nicksanto882]

Loud and clear! Thanks!!!

[@michaelpadovani9566]

Great series and topic, I learned a new configuration for the memory bank.

[@zabuza55]

Why the output voltage dropped when connected to the lamp?

[@joejane9977]

@6:00 you talk of no current draw this is kinda true. there is no current load extra from the op amp. the zener will be sourcing current but it is isolated by op amp. a resistor between your 12 and zener will limit current thru zener too. these are minior points and said for greater understanding. than you for your videos and wisdom.

[@thenoisyelectron]

Besides the great content, I love that channel intro! A+++++

[@rogerfurer2273]

Always check the data sheet for "how Lo can it Go"; usually VOL: Output Voltage Range. This will tell you the smallest Z the amp can drive.

[@abhilashchaturvedi4575]

Thank you!

[@BryanDenham]

thank you for the help

[@ChrisFredriksson]

Really good explanation! Thank you!

[@johnjeremias9437]

good video and explanation. better please if you make close up larger view of circuit

[@bblod4896]

I ask the same question as Techno P. No current limiting resistor for the Zener? What am I missing?

[@learnelectronics]

Oy vey

[@bblod4896]

@@learnelectronics Your Yiddish is getting much better 😆

[@TheEmbeddedHobbyist]

A resistor to limit the current if the voltage fed to the zener has passed it zener voltage. From this point is will take any current it can get, well till it goes pop :)

[@MikeTechnology]

Good to know thank you for you well done video about old circuit that's really useful 👍 thank you

[@ertreri]

Many thanks.

[@daxor483]

Ty ! Really helpfull !!!

[@opalprestonshirley1700]

Love this series. Looking forward to your 100K. Stay safe.

[@duftcola]

Great job.Thanks for the video

[@utkf16]

Great explantion thank you

[@nathanas64]

Fantastic explanation thank you!

[@ae1tpa92gwtom2]

great, hoping to see more using op-amps,.. enjoying the refreshers,... cheers. oh, n 73,.. cheers

[@smallfry8788]

You should make a playlist of classic circuits you should know.

[@learnelectronics]

I have over 20 playlists, including classic circuits you should know

[@georgechambers3197]

More goodness from the dark crevices of Paul's mind. 😁 Thanks, for the video!

[@microhobbyist]

In Multisim, why is the output at 1.666V if it's a voltage follower?

[@learnelectronics]

I explained that in the video. The load is pulling the voltage down.

[@zetaconvex1987]

@@learnelectronics I thought the point was that the output voltage was the same as the input voltage?? But now you're telling us it isn't. What do you mean by the "load is pulling to voltage down"? Doesn't the full 2.55V drop across the load? Or is it only 1.67V? I don't understand what's going on.

[@StevenReiber]

@@zetaconvex1987 Op amp can only supply so much current, so it drops to the maximum voltage it can to supply that current to the load

[@willtipton]

you should do a more indepth video on optocouplers and the uses / implimentation

[@TOMTOM-nh3nl]

Thank You

[@PeterMilanovski]

Paul buddy, what's that software that you are using for this demonstration? It's not for me! I'm asking for a friend, no really LoL.. I already know all this stuff! But I enjoy watching! ( That really sounds dirty 😂).

[@learnelectronics]

Multisim from National Instruments...it's free

[@PeterMilanovski]

@@learnelectronics thank you! I'm going to have to get a copy of it before someone somewhere might realise that it's actually useful and put a price on it LoL.

[@TheDefpom]

Lol, I will be publishing a video soon on a similar subject, for a project I have been working on.

[@keithking1985]

Ideas for getting ya over the 100K. why dont you do a review of some of most viewed videos, and see who things you got have held up since you got them.. stuff like that.. and go right back to basics on one half of a video and maybe integrate it into harder stuff on the second half. i wouldn't mind a little component lesson in a video and sure others either.. Really cant wait to see 100K there beside you channel name!! : )

[@MDJ5]

is this opamp configuration what they call 'unity gain' in audio circuit terms?

[@GORF_EMPIRE]

Yes it is. But the term applies in DC or AC circuits.

[@MDJ5]

@@GORF_EMPIRE oh i didnt even notice that this was a DC circuit - I kinda already knew but found it weird he didnt mention it and no one likes those a-hole's commenting on videos how "i kNoW beTtEr ThAn tHis gUy", ya know? thanks for cluing me in ;)

[@GORF_EMPIRE]

@@MDJ5 The point you should take away from this circuit is that it's a buffer. They work pretty much the same for AC or DC signals. They maintain the voltage level either way.

[@MDJ5]

@@GORF_EMPIRE random related question: which opamp has the fastest slew rate you can think of?

[@GORF_EMPIRE]

@@MDJ5 Of the top of my head, I could not tell you...it's been a long time since I messed around with this stuff. Best to look it up.

[@Jose_T131]

Great !

[@trinity8717]

If anyone tries to build this then expect smoke. The zener will fry. Hes been told this many times already. Its a case of not knowing how to use simulation software correctly that makes him think the circuits ok. Beware.

[@dampandrew]

you can reverse the issues, aging will only make it slightly more difficult but not impossible. A great starting point is to try focusing on the meditation, the rest will happen automatically, to increase the longevity of your arteries I would suggest daily raw garlic, eaten very fresh chewed on empty stomach, i guarantee.

[@dentakuweb]

Why bother with the zener? Couldn't you just just use the correct combination of resistors to get 2.5V? Something like 15K and 3.9K would give you roughly 2.5V.

[@markhall3323]

Your hand is covering the page and we can’t see what you’re writing maybe consider pre-drawing and make it all larger

[@hugovangalen]

Shouldn't the title be "Classic circuits you should know - Voltage follower"? (Note where the "-" is.)

[@kac3514]

For simulation you should also check www.falstad.com/circuit/ it is free and it is awesome

[@EnergeticWaves]

I don't see what problem this solves.

[@markgreco1962]

Paul, 2 ads in 10 minutes. fyi

[@learnelectronics]

In the middle of the video????

[@learnelectronics]

I just checked and KZbin turned the mid-roll ads setting back on after I disabled it. Thank you and please bring this to my attention any time you see it.

[@markgreco1962]

learnelectronics I listen during the middle of the night and wake up a little smarter Thanks Paul

[@DavidSprings]

First!

[@rjmendoza]

Second but in still watching lol