This part is a kind of semiconductor called BD951.

Function of this product has (BD949 - BD956) TO-220 Plastic Package.

Manufacturers : CDIL

Image and pinout :

Some of the text within the PDF file :

Continental Device India Limited An IS/ISO 9002 and IECQ Certified Manufacturer TO-220 Plastic Package IS/ISO 9002 Lic# QSC/L- 000019.2 IS / IECQC 700000 IS / IECQC 750100 BD949, BD951, BD953, BD955 BD950, BD952, BD954, BD956 BD949, 951, 953, 955 BD950, 952, 954, 956 NPN PLASTIC POWER TRANSISTORS PNP PLASTIC POWER TRANSISTORS Power Amplifier and Switching Applications PIN CONFIGURATION 1. BASE 2. COLLECTOR 3. EMITTER 4. COLLECTOR 4 1 2 3 B H F C E DIM A B C D E F G H J K L M N O MIN . 14.42 9.63 3.56 MAX. N L O 1 2 3 D G J M 16.51 10.67 4.83 0.90 1.15 1.40 3.75 3.88 2.29 2.79 2.54 3.43 0.56 12.70 14.73 2.80 4.07 2.03 2.92 31.24 DEG 7 A O ABSOLUTE MAXIMUM RATINGS Collector-base voltage (open emitter) VCBO Collector-emitter voltage (open base) VCEO Collector current [ ... ]

BD951 PDF Datasheet Download