#1090

[@Enigma758]

These are among my favorite kinds of videos as they get me thinking about practical circuit considerations. Also, another great example of "use what you have to make what you need". Brilliant!

[@rjrodrig]

it would be nice to see the stability of the loop by doing a current load transient

[@mrlazda]

No need to do transport test, loop stability is terrible, this is better as oscillator then as it is as voltage regulator for any practical purpose.

[@CueBallFunStuff]

Thank you for your well done instruction of this op amp circuit 🙂

[@CrystalLizard96]

What happens to the supply voltage? To me it looks like the output voltage should be the output from the amp plus the supple voltage minus the transistor voltage drop? I guess I'm missing something obvious?

[@plainedgedsaw1694]

You're a bit wrong here talking about the 317, it has bandgap Vref at 1.25V, and - input of op amp tied to output, Adj pin being in series with the reference.

[@dixsusu]

LM 723 , my first op amp for building these liniars , 7805 didn't existed on mass productions back there. Good video , now some overvoltage protection please .

[@jeffreywyke368]

The transistor is commonly referred to as a PASS TRANSISTOR. Good video... thanks!

[@henriquecasonatto8881]

its possible to do this without -12v supply ?

[@argcargv]

A -12v supply isn't necessary, but if you will want to make sure that your voltage reference is compatible with the common mode input range of the op-amp. Some op amps can go all the way to one or both rails. For example, the ubiquitous LM358 inputs are spec'd to go all the way to the negative rail. So that would be one you could use instead to make it work on just a 12v supply. With a 3.2 volt reference as shown here even the TL072 will work with a single rail supply.

[@NackDSP]

I would look to eliminate the -12 V supply and the 100 ohm resistor. I doubt that op amp can produce enough current to damage that transistor. I would also use a higher voltage Zener, maybe 5.6 volts to eliminate the expensive potentiometer.

[@alnoorratansi9364]

Great Video, Will this work with single 12v power supply ? with LM358 ?

[@IMSAIGuy]

I think so

[@PF-gi9vv]

It does, I built this power supply 30 years ago using the LM358. And it works without the -12v. Its still working till this day :)

[@aishwaryasai9746]

Hope you are doing well. I have a doubt regarding my design of the amplification circuit with an op-amp to amplify the voltage. I have a few doubts regarding the op-amp designing circuits. QUESTION: I need a bipolar output of +/-15V using an op-amp where the input of the non-inverting op-amp is a sinusoidal signal with amplitude of 3.3V from a microcontroller with frequency=40kHz from a DAC unit. But the problem is when I am simulating its outputting the same voltage though I have chosen R2 and R1 resistor. Can you please help me with this issue. Thank you

[@IMSAIGuy]

sounds like you need to study and try some examples that are known to work

[@mulx3867]

this circuit can works with 3.3v zener?

[@hadibq]

Very nicely explained 👍

[@rudygomez6996]

Something as simple as zener diode can be used as voltage regulator, correct? What advantages does this circuit have compared to just using a zener diode? Thank you!

[@NackDSP]

Efficiency. A 5 amp Zener diode would have to shunt 5 amps or more to enable output of 5 amps when needed. I've never seen a 5 amp Zener, so you would need a bunch in parallel.

[@rudygomez6996]

@@NackDSP thank you very much for answering!! That makes a lot of sense :)

[@MechanicForGMCCars]

Hello sir me ignition coil is e core design and it uses the mc 3444 ic chip set . I wanted to ask is there any way that I can use voltage regulator,dimmer circuet or any other means to control that ignition coil externaly??? I have realy problems starting me car that 4pin gm ignition module does not have retarding option so I hoppe to build me self that can help me easyr start me car in winter or some sort of resistor capacitor box combinations or frequency controlers any thing just to make that thing some what more variabel. If not can you sugest some external variabel circuet like buzz coil design? I was also wondering can those positive linear voltage regulator back fead ? I have lately unusual effect in me engine its self acelerates I cant licate the problem .

[@jaymclemore9497]

I enjoy your videos very much and I am trying to learn about opamps, but just don’t get them yet. Can you recommend a good beginner video?

[@IMSAIGuy]

this series might help: kzbin.info/www/bejne/kGmtdaasm7-dgpo also videos #858 #859

[@deanedgx]

I want to regulate a 50v supply. Can it be done using your circuit?

[@IMSAIGuy]

No

[@user-power_electronics]

This circuit only work at low current. When increase load in the range of few amperes, the output voltage will collapse. Load current increase will cause base current increase and op-amp can't handle high output current to drive the power transistor directly.

[@IMSAIGuy]

yes, you would need a darlington or a high current opamp.

[@rickb.6068]

Thanks for the great explanation and simple circuit to build and use.

[@alnoorratansi9364]

If the input voltage changes, does the out change ? in my circuit it does.

[@IMSAIGuy]

it will change a small amount, the zener diode voltage changes with current.

[@6WTF_MAN9]

Работать то оно будет, но устойчивость схемы к непостоянной нагрузке под вопросом. На каких то частотах может начать осциллировать.

[@t1d100]

A great subject and a great video. I would love a series which builds a 30V/3A Lab Linear Power Supply, with a true zero volts, constant current, bells and whistles, etc. And, explanations of how each section of the circuit works. Please and thank you. IMHO, power transistors are expensive. That has nothing to do with the video; just saying...

[@cellularmitosis2]

A classic! Thanks.

[@jj74qformerlyjailbreak3]

Great talk coach. Now can we do a Jellybean boost circuit?

[@IMSAIGuy]

I have several videos on that subject: kzbin.info/www/bejne/jJumdpmaeMpniMk

[@IMSAIGuy]

kzbin.info/www/bejne/b5Oph4eXbat4g5Y

[@Yorumcu63]

Great video about adjustable power suppys. I have questions : If I want more low voltage from 3,3 volt I must use more low zener diode ? and ıf ı don't use zener in there ,voltage output begin 0 (zero )volt ? I think I can use more powerfull transistors I can make more power power supply like 5 Ampere Could you make a video in same base circuit with current limiting and 2-3 ampere too ,ıf possiable 1-2 transistor adding increase current too (I mean maybe a darlingtan transistor or more efficiency new transistor) Thank you for great video

[@IMSAIGuy]

if you need a voltage lower, just follow the zener with a resistor divider.

[@frankowalker4662]

Neat and accurate. But I prefer the 7805 regulator, you only need one power rail. :)

[@AnalogDude_]

this works just the same with the opamp hooked to one power rail and gnd or uni polar supply.

[@anandar1158]

Hi @IMSAIGuy sir, Could you please make some practical videos on how voltage and current behaves in capacitor and inductor. And also how power delivered when these components are present in the circuits. If possible please make one on why imaginary numbers are used in the AC circuit analysis.

[@IMSAIGuy]

for LC this might help: kzbin.info/www/bejne/aWWqZaOwjNdsoaMsi=cHOnhdyKbsOIK5_S I have thought about how to teach the subject of imaginary numbers. It is not easy to make a simple video as it requires a bit of math. But, I will try someday

[@anandar1158]

@@IMSAIGuy thank you so much

[@KenYOW]

Thanks!

[@marcospy2tki767]

olá IMSAI. Ótima explicação. Sobre o circuito inicial, eu acho que é uma aplicação de amplificador operacional, circuito não inversor. em que o Ganho de tensao Gv = (Vo/Vi) = (1 + R2/R1) , sendo o R1 = parte de cima do VR=10k, e o R2 = parte de baixo de VR=10k. O TR NPN serve de booster de corrente para o amplificador operacional, se o IC pode fornecer 1mA, com o TR, esse fator é "multiplicado por hfe", em que o hfe está entre 10 a 20 em TRs de potência. No caso, como a topologia é amplificador não inversor, a fonte de alimentação negativa pode ser dispensada, colocando o pino do IC no GND... Mas isto pode provocar que a tensão de saída não comece em Zero Volt (como no caso do LM723). Veja que se R1 = R2, nós teremos Vo = 2*Vi = (2 * 3.1) = 6.2V... A relação entre R1 e R2 define o valor da tensão de saída da fonte... 73

[@Jibs-HappyDesigns-990]

U and U'r little knobs & buttons! U do these little op-amps every so often! so U could power this, with a 9V battery. this guy, & his big fancy power supply! wait? why am I harassing him!🤔I ponder, & wonder! but, does this grow fonder? I'm glued 2 my mattress, @ the moment! bla..bla...bla.. good luck with it!