Therefore, if we have a way of holding emitter current constant through a transistor, the transistor will work to regulate collector current at a constant value.
于是，只要我们能让晶体管的发射极电流保持恒定，它就能保持发射极电流为恒定值。
2
Regardless of type NPN or PNP-type tubes, the internal transistor has three areas, namely, the launch area, base, collector area, the three areas form two PN junction.
无论npn型还是PNP型管，三极管内部均有三个区、即发射区、基区、集电区，三个区形成两个PN结。
3
The collector voltage of the switching transistor is determined by the voltage of the power network.