维基对反馈的电子电路分类下有说明，见下
https://en.wikipedia.org/wiki/Feedback#Electronic_engineering
The use of feedback is widespread in the design of electronic amplifiers, oscillators, and stateful logic circuit elements such as flip-flops and counters. Electronic feedback systems are also very commonly used to control mechanical, thermal and other physical processes.
对于无源电路，如果用电路增益去描述反馈后的变化就不合适了。 |
楼主
