Any resource to understand the basic feedback operation in electronics?

[mohannad]

I have a basic understanding of the concept of feedback and the control theory in general, but i was going through "art of electronics"
and i really liked the introduction of the concept of feedback but transistor circuits looks very tricky.
when dealing with feedback using op amp it's quite easier but when it comes to transistor things get complicated. 

Any recommendation on this specific concept? any recommended resources?

[LvW]

I have a basic understanding of the concept of feedback and the control theory in general, but i was going through "art of electronics"
and i really liked the introduction of the concept of feedback but transistor circuits looks very tricky.
when dealing with feedback using op amp it's quite easier but when it comes to transistor things get complicated. 

Any recommendation on this specific concept? any recommended resources?

For a single transistor stage, there are in principle only two (negative) feedback alternatives:
(1) With respect to the collector output, the base is an inverting input. Therefore, we can apply the basic feedback principle known from the opamp feedback scheme: (a) A resistor RB between collector C and the base node B or (b) a voltage divider between C and ground (midpoint at B)..
Here it is possible to directly observe the feedback loop.

(2) In contrast, using a feedback resistor RE (emitter path), the feedback loop  cannot be visually identified. However, using the small-signal parameter gm (transconductance) we can find an equivalent diagram which clearly shows the feedback loop (see attached jpg file):
In this simplified diagram I have used the assumption IE=IC (a somewhat extended diagram including the base current IB can be easily found).