Talk:Loop gain

Complex number?
Nearly 40 years ago I learned in university that the loop gain (including its phase shift) can be depicted on the complex number plane, and should avoid the point -1 (or more precisely: -1,0). Could WikiPedia help me to refresh my memory? — Preceding unsigned comment added by 81.207.20.42 (talk • contribs) 22 apr 2009 14:32‎ (UTC)

>Somewhat. Its curve should not surround (-1,0) on the complex plane if the system needs to be stable (e.g. not produce oscillations and not raise the signal indefinitely). --86.35.173.100 (talk) 22:39, 31 January 2011 (UTC)

Gain in Respiration
I was surprised to see the paragraphs on respiration in this article. That's OK, I'm allowed to be and might quite often be surprised. But, it almost seems like respiration has been snuck into the article, in two respects.

First, in the paragraph after point #2 that seems to start off being about gain in general ("Loop gain is an engineering term used to quantify the gain of a system controlled by feedback loops."), and then, without much warning, starts talking about respiration.

Second, if it's going to talk about gain in respiration, it should make it more clear that the discussion about respiration is only one example of the use of gain, and there are many other possible examples.

Third ;-), imho, it's a very non-traditional example of the use (or application, or whatever) of gain.  Maybe the non-traditional example is good, but then maybe at least equal weight should be given to a more traditional example.

I'm going to make an attempt at modifying the article based on my comments above. —Preceding unsigned comment added by Rhkramer (talk • contribs) 13:08, 23 May 2011 (UTC)

UPDATE: OK, I made some changes. I should say that I am not a biologist, nor do I know that the concept of loop gain is "traditionally" applied to respiration. My edits were based on the assumption that it is a fairly "traditional" application. If I'm wrong, this might be an instance of "Original Research". Someone else would have to judge that.

Finally, just one more opinion--I didn't try to address this point, but it seems to me the discussion of respiration goes into too much depth for an article on loop gain. Maybe some of it should be moved to (or already is in) an article on respiration, and the discussion here should be shortened and then a link provided to a more in-dpeth discussion.Rhkramer (talk) 13:27, 23 May 2011 (UTC)