晶体管的重要特征

2015.the_art_of_electronics.horowitz.pdf: Chapter 2: p99

Note that voltage amplifica- tion isn’t what matters, since, for example, a step-up trans- former, a “passive” component just like a resistor or ca- pacitor, has voltage gain but no power gain . 1 Devices with power gain are distinguishable by their ability to make os- cillators, by feeding some output signal back into the input.

可以将输出反馈到输入！