# 120 leading and 120 lagging from 10sin(wt)

Discussion in 'Homework Help' started by charliekasper15, Apr 15, 2016.

1. ### charliekasper15 Thread Starter New Member

Apr 13, 2016
4
0
First of all, I would like to add that I am very sorry but I have ZERO IDEA on this. Absolutely no idea whats what but I am hoping I learn something really quick from this circuit. My project exam is on tuesday (18th April) and Theory exam is on first week of may (thats when I will start reading about the subject). Now on project topic.

My project is to create a circuit that will take input of 10sin(wt) and create two outputs 10sin(wt+120) and 10sin(wt-120).

I collected a circuit from another guy who has the same project. Attached below.

I used multi sim to create that circuit.

I gave an input of 3khz and 20 mV.
For leading 120*, I got this output.

For lagging 120*, I got this output.

I have no idea whats what and now I don't know what to do. PLEASE PLEASE PLEASE help me, I have the test on monday, once I create the circuit I will have a guy make me understand whats happening in the circuit, all I need first is a working circuit. I also have to write a report on it.

All I ask on this forum is to see whats wrong and fix it and I will take care of the understanding and report writing. You don't know me or owe me anything but I will forever appreciate your help.Please.

2. ### ericgibbs AAC Fanatic!

Jan 29, 2010
2,604
396
hi 15,
Check the polarity of your 741 OPA power supplies to pins 4 and 7, in the simulation.

E

3. ### charliekasper15 Thread Starter New Member

Apr 13, 2016
4
0
For both the opamps, I gave -12V input to 7 number pin and 12V input to 4 number pin. For leading the output flatlined and for lagging the output went from positive Y axis to negative Y axis.

Apr 5, 2008
15,806
2,390
Hello,

Also check the connections of R6.

You might also want to know that the circuit will be frequency dependend.

Bertus

5. ### charliekasper15 Thread Starter New Member

Apr 13, 2016
4
0
What needs to be done? I suspected that R6 needs to be put in the #2 pin and not to the ground after R8. Is it that?

Apr 5, 2008
15,806
2,390
Hello,

Just compare it with how R5 and R9 are conected.

Bertus

7. ### WBahn Moderator

Mar 31, 2012
18,093
4,920
You might give some thought to how you approach learning things. You have a theory exam the first week of May and you are going to wait until then to start studying the material. Meanwhile, you have zero clue how to do anything on a project less than a week before the exam on it. Did you wait until a week before it was due to start on it, too. Then you want someone else to fix your circuit for you so that you can have yet someone else tell you how it works. There's a trend here. Perhaps the reason you have no clue is because you have never been willing to roll up your sleeves and do anything for yourself.

panic mode likes this.
8. ### charliekasper15 Thread Starter New Member

Apr 13, 2016
4
0
That's pretty harsh, the truth nonetheless.

9. ### WBahn Moderator

Mar 31, 2012
18,093
4,920
Yes, it is harsh, but it's meant to help you. Sometimes that's what we need to take a step back and evaluate our behavior and make a change. We all get stuck in patterns of behavior that aren't good for us, but because they are familiar we don't see them for what they are. Having it thrown in our face in stark terms can sometimes shake us out of our complacency. Hopefully that's what will happen for you. If not, you are just digging yourself a deeper and deeper hole that you will never be able to find your way out of.