2N2222
2N2222 Transistor
https://en.wikipedia.org/wiki/2N2222
The 2N2222 is a common NPN bipolar junction transistor (BJT) used for general purpose low-power amplifying or switching applications. It is designed for low to medium current, low power, medium voltage, and can operate at moderately high speeds.
The 2N2222 is considered a very common transistor, and is used as an exemplar of an NPN transistor. It is frequently used as a small-signal transistor, and it remains a small general purpose transistor of enduring popularity.
NPN silicon transistors with similar properties are also made in a variety of small through-hole and surface mount packages including TO-92, SOT-23, and SOT-223.
The 2N2907 is an equally popular PNP transistor complementary to the 2N2222.
Vce Ic PD fT 40 V 800 mA 500 mW/1.8 W 300 MHz
All variations have a beta or current gain (hFE) of at least 100 in optimal conditions. It is used in a variety of analog amplification and switching applications.