Hello, it's the end of the semester and one of my things to do is to explain:
How does the μA741C amplifier work, what are its specs?
Where is it used?
What's the function of the offset-voltage null capability in it?

The problem is that the teacher didn't say a thing about it maybe because he gave the assignments at the beginning of the year and because of covid he had to shorten the material or maybe he just didn't want to talk about it at all, yesterday he sent me an "explanation file" from a market store like texasinstruments or something, which answered 1 question, that I didn't put in this thread. I searched in forums and in youtube, but I couldn't find anything particular. I'd be really thankful if somebody helped. I'll attach the amplifier's scheme.

 

Look up the data sheet for the 741 op amp, and look up the definition of operational amplifier.
After you've read those come back here with your questions.

 

Hello, it's the end of the semester and one of my things to do is to explain:
How does the μA741C amplifier work, what are its specs?
Where is it used?
What's the function of the offset-voltage null capability in it?

The problem is that the teacher didn't say a thing about it maybe because he gave the assignments at the beginning of the year and because of covid he had to shorten the material or maybe he just didn't want to talk about it at all, yesterday he sent me an "explanation file" from a market store like texasinstruments or something, which answered 1 question, that I didn't put in this thread. I searched in forums and in youtube, but I couldn't find anything particular. I'd be really thankful if somebody helped. I'll attach the amplifier's scheme.

View attachment 227668

Hello,

Well if you really want to know how the 741 works you would have to study the internal diagram. However i think that might be beyond what you actually want to do.

You can look up the specs that's not hard. The internet is wonderful for this. When i was just starting out we had physical books and books and books to look up specs for various parts. Now we have the internet and all you have to do is type the part number into a search engine and you will get lots of hits.

As to the question of what the 'null' does, you would have to read up on what an offset null for an op amp is and why it is useful. There isnt much to it really.

You could at the same time look up various applications that the 741 is used in and you will find there are a lot. There are limitations to this op amp that sometimes get in the way but you will find that out when you look up the specs on the internet. You will have a lot to read but you should find it interesting.

 

Hello, it's the end of the semester and one of my things to do is to explain:
How does the μA741C amplifier work, what are its specs?
Where is it used?
What's the function of the offset-voltage null capability in it?

The problem is that the teacher didn't say a thing about it maybe because he gave the assignments at the beginning of the year and because of covid he had to shorten the material or maybe he just didn't want to talk about it at all, yesterday he sent me an "explanation file" from a market store like texasinstruments or something, which answered 1 question, that I didn't put in this thread. I searched in forums and in youtube, but I couldn't find anything particular. I'd be really thankful if somebody helped. I'll attach the amplifier's scheme.

View attachment 227668

If you are paying for education and getting less than you expect you need to take that up with the provider. As others have noted you have many resources available to you that we never did. Some combination of books internet articles or even You-tube videos should at least set you on the correct path. I will give you a couple of hints:

1. No current flows into either of the amplifier inputs. They are very high impedance.
2. At any node in the circuit, the sum of the currents must be zero.

For example if U1 is the voltage at the junction of R1 and R1, the currents are (U0 - U1)/R2 , and (U1 - Ug-)/R1, and 0 which goes to the amplifiers inverting input.

 

Here is a valuable reference. It pre-dates the LM741 but it gives an excellent introduction to opamps as well as some application information.

https://www.ti.com/lit/pdf/sboa092?keyMatch=BURR-BROWN OPAMP MANUAL&tisearch=Search-EN-everything

 

To be honest I don't know if you'll get a notification for this, but you really helped me out, I'm more than 3/4 done with the assignment. The main challenge is to explain everything in Bulgarian afterwards, that's why I need someone to explain it to me correctly. I have 1 new question, which is: what is the transmission characteristic (transmission curve) called for the file I've attached.



The question "how do I properly explain how does the μA741C work" remains

 

I searched in forums and in youtube, but I couldn't find anything particular.

Your instructor probably intended for you to look for the information. It's widely available on the internet if you know where to look for it.

Hint - look for a Signetics Analog Handbook from the late 70's (yes, that's how long the information has been readily available).

 

Update: I answered the question about the characteristics and how is it called. Now I need a source, where I can get something like an algorithm of how the amplifier works. I'll check out everything new you've suggested.

 

I agree that the "teacher" is absolutely useless. The 53 years old 741 opamp is also useless and should be buried.

 

Hello,

Here I have two datasheeta of the ua741.

Bertus

 

I agree that the "teacher" is absolutely useless. The 53 years old 741 opamp is also useless and should be buried.

hi agu,
Where does it say in this Thread that the "teacher" is absolutely useless, that you are agreeing with.??

Its most likely not the teacher who is at at fault, they usually have to teach a predetermined curriculum, using the material resources allocated to the course.

E

 

hi alex,
Check thru this video, it covers OPA's in general, you can use the PDF's in post #10 as a comparison reference.
E

 

I agree that the "teacher" is absolutely useless. The 53 years old 741 opamp is also useless and should be buried.

You should not forget that the task is to EXPLAIN something. And it is not too bad - as a first example - to choose an amplifier topology that is relatively simple to understand.
More than that, there are hundreds (if not thousands) articles and application hints based on the 741 reference.
In case you want to develop a new electronic circuit - you are, of course, free to select another device.

 

The question "how do I properly explain how does the μA741C work" remains

That question is very vague.
At what level of explanation are you needing.?
Certainly if you want a transistor-by-transistor explanation of how it works internally, that's beyond the scope of this forum.

The 741 is an op amp.
Do you know how op amps work?
If not, then you need to study that.

 

I said that the teacher is useless because the semester has ended and the teacher did not teach what is needed for the assignment. Post #7 said, " Your instructor probably intended for you to look for the information" instead of teaching it. I agree with that.

 

I agree that the "teacher" is absolutely useless. The 53 years old 741 opamp is also useless and should be buried.

But hey you love that op amp!

 

Old teachers use old 741 opamps. I bet most old teachers know nothing about modern audio opamps, Cmos opamps and rail-to-rail opamps.

 

Old teachers use old 741 opamps. I bet most old teachers know nothing about modern audio opamps, Cmos opamps and rail-to-rail opamps.

Certainly would not be the first time i heard strange stories about so called 'professors'. They got their degrees at Walmart University.

 

Certainly would not be the first time i heard strange stories about so called 'professors'. They got their degrees at Walmart University.

I am 75 years old - I was teaching analog electronics for 25 years at a "University of applied Sciences". I have treated, for example, analog filter solutions based on opamps, current feedback amplifiers, current conveyors, OTAs as well as discrete transistors.
Satisfied?

Quote: "Your instructor probably intended for you to look for the information" instead of teaching it."
It is quite a challenge to find a suitable balance between "teaching" (by a lecturer) and "self-teaching" (by students). Don`t overlook the importance of the latter

 

I did a 15 page write up and built a discrete uA741 as a final project, although I don’t go into the details of my write up you may find this thread an interesting diversion about your topic

https://forum.allaboutcircuits.com/threads/discrete-741-build-final-project.164101/