I am currently digging into some amplifier feedback analysis tools papers and literature. I found some "term" right at beginning of this topic that I don't quite understand. That is "Error equation of system/circuit". Simple feedback system incorporating this term looks like this:
At the beginning I thought of it as being a closed loop error or something in that direction, but this figure represents it as something else. So, system error (or E) is just a summed signal resulting from \$V_{IN}\$ signal and \$\beta\$ (or feedback path signal)?
Also, in paper I am currently learning from (published by Texas Instruments) gives these three equations for feedback system (incorporating E):
$$ V_{OUT} = EA $$ $$ E = V_{IN} - \beta V_{OUT} $$ $$ E = \frac {V_{IN}} {1+A\beta}$$
These equations tells me that System Error actually is a summing output. But why is it named "Error"? I first thought of it is being some miscalculation of fault term. And I probably wasn't the first that thought of it this way.
