Possible error in AC vector addition ebook topic


Joined Mar 24, 2008
You are going to need to be a bit more specific where you thing the problems are. Cut and paste the actual error, for example, along with the link where you got it.

I saw no errors in the chapter. When the phase angles were 0° they added. When they were 180° they were subtractive. In all illustrations this was spelled out.

If you are having problems with the concepts (and don't think it is an error) this is not the forum to bring it up in, you need to post in the Electronics Chat forum and ask the questions.

Feedback and Suggestions Forum for providing feedback and suggestions about All About Circuits, including corrections to the e-book. This forum is not for getting help with technical questions.

Thread Starter


Joined Jan 6, 2012

I was on a phone so couldn't cut and paste effectively and I realise this is the sub forum for posting comments and not questions. So, just ot explain my 'error':

RE: http://www.allaboutcircuits.com/vol_2/chpt_2/3.html

Extract 1

Similarly, if AC voltage sources with the same phase angle are connected together in series, their voltages add just as you might expect with DC batteries: (Figure below)

“In phase” AC voltages add like DC battery voltages.

And then, Extract 2:

We could have just as well shown the opposing voltages subtracting in series like this: (Figure below)

Opposing voltages in spite of equal phase angles.

My original assumption was:

The power sources are the same in 'Extract 1' as in 'Extract 2' but the overall voltage is, I think, illustrated wrong in 'Extract 2' as the phase angles are the same for both the -6+v and -8+v sources.

But 'Extract 2' has a cheeky twist in the wire across the 8v source so there is -6v++8v- hence all is fine.....!