AC circuit: 2 Dependent sources (Confirmation with software)

The Electrician

Joined Oct 9, 2007
2,750
On the second page of your calculations you have:

I6 + I1 = 2 Vo + I5 ==>

(10-V3)/2 +.........

The expression for I6 is not correct; it should be: (V4+10-V3)/2

Show us your results after you make the correction.
 

MrAl

Joined Jun 17, 2014
6,644
Hello,

I was found the node's voltages of the circuit and I want a confirmation. Can someone verify using a software ?

This is my try: https://docdro.id/AontV5p

The circuit:
View attachment 191155

Thanks.
Hi,

The general rule for this site is to upload all of your images to the forum itself so that this site does not have to depend on external sites to maintain images. If the site you upload to goes away for any reason then this thread becomes useless to others in the future.
 

The Electrician

Joined Oct 9, 2007
2,750
In your first working (in the image attached to post #1) you had an expression for I5 of (V3-V4)/-j2

In your latest working you have an expression for I5 of V3/-j2. This doesn't seem right; can you explain why you changed it?
 

Thread Starter

michgkou

Joined Oct 3, 2019
37
Hi again,

Question, why did you make the cosine source 0 degrees and the sine source 90 degrees. Shouldnt it be the other way around? Normally a sine source is taken to be at 0 degrees and a cosine at 90 degrees because the sine source passes though 0 volts (or amps) at 0 degrees.
sine is minus 90.
 

MrAl

Joined Jun 17, 2014
6,644
sine is minus 90.
Hello again,

Well thanks but that is not an explanation of why you made the cosine source 0 degrees and the sine source minus 90 degrees. The cosine source peak starts at 0 degrees not the zero crossing.
A sine source is normally placed at 0 degrees. If you change that to -90 then all your phase shifts will be different by 90 degrees.

So the question is what is making you place the sine source at -90 degrees? What told you to do that? We already know you did that, but what caused you to believe you should make it minus 90 degrees? Did some instructor tell you to consider the cosine source to the the reference source or what?

For another example, if you had a source of sin(w*t) and another source of sin(w*t+30 degrees) would you arbitrarily make the 30 degree source the reference phase? No, not unless there was something else in the system that suggested you should do that or the instructor told you to do that or some other good reason.
 
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