TIP122 NPN Power Darlington Transistor (TO-220)

The TIP122 occupies the same role as the TIP120, using two internally combined transistors to multiply current gain so a small logic-level signal can switch several amps directly, but with a higher 100V rating that gives it extra safety margin in circuits running closer to that voltage ceiling. That makes it a practical choice for switching DC motors, solenoids, and relay coils from a microcontroller pin in projects where the supply voltage runs a bit hotter than a basic 60V-rated part would comfortably handle, without needing a separate driver transistor stage in between the logic signal and the load.