# Circuit equivalence clarification

Discussion in 'Homework Help' started by croese, Jan 26, 2009.

1. ### croese Thread Starter New Member

Jan 23, 2009
3
0
I'm still getting the hang of visualizing what a given circuit configuration will do and so I still do a fair amount of converting circuits into more recognizable diagrams. So, I was wondering if anyone here could tell me whether the circuits in the attached schematic are all the same. C1 is the original and C2 and C3 are conversions. For C2, I used the "tracing" method in the textbook from this site and for C3, I converted the lower group of 3 resistors from a delta-type to a y-type (which is why the resistors are labeled RT# since they'll be different values).

Also, I'm not sure if everyone can read the asc file I attached, but whenever I try making a bmp, it always comes out way too big to post here. What do others use to post schematic images? I made the schematic in LTspice IV, btw.

File size:
2.3 KB
Views:
15
2. ### beenthere Retired Moderator

Apr 20, 2004
15,815
282
No, every circuit is different. The differences should be obvious.

3. ### croese Thread Starter New Member

Jan 23, 2009
3
0
I may have used the wrong word when I asked if the circuits were the same.

I realize that the specifics will change as I change the circuit itself around. What I wanted to know is if I rearranged the original circuit correctly so that the resistors remain in the same configuration, but with a layout that's easier to read and see what things are in series or parallel with each other.

Basically, I'm more concerned about whether I can change the original into C2 so that I can remove the bridge and so make the calculations (for total resistance, voltages, current values, etc) easier to do and the operation of the circuit a little easier to visualize since I can clearly see what things are in series or parallel to others.

As for C3, I saw that technique in the textbook I'm reading and I wanted to get an opinion from someone more experienced as to whether I am using that delta-to-y conversion correctly.

Last edited: Jan 27, 2009
4. ### Ron H AAC Fanatic!

Apr 14, 2005
7,050
655
To save an LTspice schematic (or waveform window), go to Tools/Copy bitmap to Clipboard, then paste into Paint. Save as a .PNG file to wherever you want on your hard drive.
To post here, just do Manage Attachments as you did to post the .asc file.

5. ### croese Thread Starter New Member

Jan 23, 2009
3
0
Thanks Ron,

I had been doing that, but it usually came out looking rather bad regardless of the format I used (bmp, jpg, gif, or png) and the file size would be rather large so the forum here wouldn't take it. I suppose that's what I get for using paint...

I did find a link to PDFonline in the FAQ that I'd missed before and it seems to work well when I have LTspice output a wmf file and then convert that to a PDF.

So can anyone else tell me whether or not my circuit conversions above are correct (in the sense that I left the components in the same configuration while making the diagram easier to read) or not?

Last edited: Jan 27, 2009