I'm stuck at couple points in the problem

Thread Starter

cikalekli

Joined Dec 10, 2020
42
hi,
Do you use LTSpice or Proteus simulator.?
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I learned by myself both of them and yeah they are already downloaded my computer. Actually the teacher wanted from us this to do with by hand but if those softwares which you mentoned is required, then they are also ready for you ^^
 

Thread Starter

cikalekli

Joined Dec 10, 2020
42
hi cik,
We need to know the Voltages Va, Vb and Vc .??

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The problem was not given those Va, Vb and Vc values.

I tried to design it via LTSpice and I have some problems on it.

Could you look at my design please?

Also I used"Universal Opamp 2" will it cause any problems or should I have been used LM741 or OP07?

Furthermore, I studied about noninverting summing amplifier design for that because it was wanted to make it as a non-inverting op-amp.
 

Thread Starter

cikalekli

Joined Dec 10, 2020
42
hi,
Without Va,b,c you cannot answer the question.

Post your LTSpice asc file.

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Just I've asked my teacher and he said that only he forgot to mention about Ra=20 kOhm and Rc=40 kOhm and gave them later.

Unfortunately, he literally doesn't accept that Va,b,c are missed... I meant he said it is possible to find them without knowing them with the help of simulation of ltspice. That statement confused me a lot...

Moreover, I attached my .asc file as you requested sir

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Probably I put the place of "Vin" on the wrong wire. I was not quite sure about that.
 
Last edited:

ericgibbs

Joined Jan 29, 2010
11,563
hi,
Your teacher is incorrect it saying that Va,b,c and the currents ia, ib ,ic can be determined in using LTS, without knowing Va,b,c.

The actual values of ia,ib,ic depend upon the applied voltages Va,b,c
If Va,b,c are 0V then Vout of the OPA is also 0V.

If you wish, ask him to contact me and explain how he can solve this without Va,b,c.

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AAA 896 12.24.gif
 

Thread Starter

cikalekli

Joined Dec 10, 2020
42
hi,
Your teacher is incorrect it saying that Va,b,c and the currents ia, ib ,ic can be determined in using LTS, without knowing Va,b,c.

The actual values of ia,ib,ic depend upon the applied voltages Va,b,c
If Va,b,c are 0V then Vout of the OPA is also 0V.

If you wish, ask him to contact me and explain how he can solve this without Va,b,c.

E
View attachment 225533
I'm really appreciative of this evidence, now I'm gonna communicate with immediately to show his missed point...

I will inform you immediately sir, cheers

Edit

I sent him this issue and he will probably reply to me after one hour. I'll inform you, sir, in the evening.
 
Last edited:
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