Function Generator-Help.

Thread Starter

Andr31

Joined May 7, 2020
4
Hello guys! I have a problem, I want to build a triangular and rectangular signal generator with adjustable frequency between 5Hz and 1kHz , output current of 60 mA and Uvv=5V. I have a figure but when I increase Rf the amplitude increases and is limited after 100 Ohm. What should I do? Thanks a loooot!


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crutschow

Joined Mar 14, 2008
24,912
Yoooou neeeeeed an op amp whiiiith a hiiiigher output currrrrrent rating than the ancient 741111111.
(Did I add enough extra characters for yooou?)
 

Audioguru again

Joined Oct 21, 2019
1,458
Most ancient old teachers use an ancient old (52 years old) 741 opamp. Some countries do not have modern things.

If you reduce the value of C1 a lot (it is a massive 10uF) then the value of RF can be increased but the frequencies will be the same. Try 0.33uF for C1 then RF can be 1.5k to as high as you want.
 

dl324

Joined Mar 30, 2015
10,702
output current of 60 mA and Uvv=5V
Not many opamps will sink or source 60mA and the LM741 isn't one of them. Is the positive supply 5V? What about the negative supply.

LM741 is not intended for operation at 5V (or +/-5V). Are you required to use this opamp? It has a number of limitations that make it difficult for novices to use.

Try to avoid unnecessary wire jogs and turn off the grid when you post.
 

Thread Starter

Andr31

Joined May 7, 2020
4
Not many opamps will sink or source 60mA and the LM741 isn't one of them. Is the positive supply 5V? What about the negative supply.

LM741 is not intended for operation at 5V (or +/-5V). Are you required to use this opamp? It has a number of limitations that make it difficult for novices to use.

Try to avoid unnecessary wire jogs and turn off the grid when you post.
No, I don't need to use this one but I don't know very well. If you can help me with another op amp I would be happy! And with advice to reach the frequency of 5Hz because it does not go below 400 Hz.
Thank you very much!
 

dl324

Joined Mar 30, 2015
10,702
No, I don't need to use this one but I don't know very well. If you can help me with another op amp I would be happy!
This post is in Homework Help. What is the learning objective for this problem? If part of it is to select an appropriate opamp we can't do that for you. If you were supposed to figure out that the LM741 wasn't appropriate; well then, we've already given you too much information.
 
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