Popular transistors.

BC639 transistor.
Pinout. Datasheet.

Type Designator: BC639.
Package: TO-92, 1-emitter, 2-collector, 3-base.
Material of transistor: Si
Polarity: NPN
Total Devise power dissipation |PD|: 0.65W
Collector-base breakdown voltage |VCBO|: 80V
Collector-emitter breakdown voltage |VCEO|: 800V
Emitter-base breakdown voltage |VEBO|: 5V
Maximum collector current |Ic max|: 1A
Maximum junction temperature |Tj|: 200 C
Transition frequency (ft) : 200MHz
Input Capacitance |Cib|:50pF
Output Capacitance |Cob|:7pF
Collector-emitter saturation voltage|VCE|:0,5V(IC=500mA,IB=50mA)
Forward current transfer ratio |hFE| : 40-160(IC=150mA,VCE=2V)