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!
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.
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 .
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.
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...
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
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.
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 .
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
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
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!
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!
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.
Thank you for your well done instruction of this op amp circuit 🙂
it would be nice to see the stability of the loop by doing a current load transient
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.
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 .
The transistor is commonly referred to as a PASS TRANSISTOR. Good video... thanks!
Very nicely explained 👍
Thanks for the great explanation and simple circuit to build and use.
its possible to do this without -12v supply ?
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.
Работать то оно будет, но устойчивость схемы к непостоянной нагрузке под вопросом. На каких то частотах может начать осциллировать.
A classic! Thanks.
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?
this series might help: th-cam.com/video/Z8JDsvfZjL8/w-d-xo.html
also videos #858 #859
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...
Thanks!
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
sounds like you need to study and try some examples that are known to work
Great Video, Will this work with single 12v power supply ? with LM358 ?
I think so
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 :)
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.
yes, you would need a darlington or a high current opamp.
Neat and accurate. But I prefer the 7805 regulator, you only need one power rail. :)
this works just the same with the opamp hooked to one power rail and gnd or uni polar supply.
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 .
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
if you need a voltage lower, just follow the zener with a resistor divider.
If the input voltage changes, does the out change ? in my circuit it does.
it will change a small amount, the zener diode voltage changes with current.
Great talk coach. Now can we do a Jellybean boost circuit?
I have several videos on that subject:
th-cam.com/video/VjCEfdCe4Rg/w-d-xo.html
th-cam.com/video/9bFVTa8FEM4/w-d-xo.html
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
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!