This part is a kind of semiconductor called 2SD1866.

Function of this product has Medium Power Transistor(Motor/ Relay drive) (6010V/ 2A).

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

2SD2212 / 2SD2143 / 2SD1866 / 2SD2397 Transistors Medium Power Transistor (Motor, Relay drive) (60±10V, 2A) 2SD2212 / 2SD2143 / 2SD1866 / 2SD2397 !Features 1) Built-in zener diode between collector and base. 2) Strong protection against reverse surges due to "L" loads. 3) Built-in resistor between base and emitter. 4) Built-in damper diode. !External dimensions (Units : mm) 2SD2212 1.5 0.4 4.0 1.0 2.5 0.5 (1) 3.0 0.5 (3) 1.5 0.4 4.5 1.6 (2) ROHM : MPT3 EIAJ : SC-62 !Absolute maximum ratings (Ta = 25°C) Parameter Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector power dissipation Junction temperature Storage temperature 2SD2212 2SD2143 2SD1866 2SD2397 Symbol VCBO VCES VEBO IC Limits 60±10 60±10 6 2 3 2 10 1 20 150 -55~+150 Uni [ ... ]

2SD1866 PDF Datasheet Download