TIP122 Transistor
The TIP122 is an NPN Transistor. In that format, we know that the base requires a voltage that is more positive than the emitter in order to allow current to flow from the emitter to the collector. The location of the base, emitter and collector of a TIP122 are shown in the picture below.
The neat thing about this transistor is that it allows for as much as 5 amps of current going from the emitter through to the collector and as much as 120 mA going from the emitter through to the base.
Equally cool is the fact that you can have as much as a 100 volt difference from the collector to the emitter and as much as a 100 volt between the collector and base.
TIP122 DARLINGTON TRANSISTOR, TO-220
Transistor Polarity: NPN
Collector Emitter Voltage V(br)ceo: 100V
Power Dissipation Pd: 65W
DC Collector Current: 5A
DC Current Gain hFE: 1000
Transistor Case Style: TO-220
No. of Pins: 3
Av Current Ic: 5A
Collector Emitter Voltage Vces: 2V
Continuous Collector Current Ic Max: 5A
Current Ic Continuous a Max: 5A
Current Ic hFE: 3A
Full Power Rating Temperature: 25°C
Hfe Min: 1000
Package / Case: TO-220
Power Dissipation Pd: 65W
Power Dissipation Ptot Max: 65W
Termination Type: Through Hole
Transistor Type: Darlington
Voltage Vcbo: 100V