This part is a kind of semiconductor called 2N6517.
Function of this product has NPN Epitaxial Silicon Transistor.
Manufacturers : Fairchild Semiconductor
Image and pinout :

Some of the text within the PDF file :
2N6517 2N6517 High Voltage Transistor • • • • Collector-Emitter Voltage: VCEO=350V Collector Dissipation: PC (max)=625mW Complement to 2N6520 Suffix “-C” means Center Collector (1. Emitter 2. Collector 3. Base) TO-92 1 1. Emitter 2. Base 3. Collector NPN Epitaxial Silicon Transistor Absolute Maximum Ratings Ta=25°C unless otherwise noted Symbol VCBO VCEO VEBO IC PC TJ TSTG Parameter Collector-Base Voltage Collector-Emitter Voltage Emitter-Base Voltage Collector Current Collector Power Dissipation Junction Temperature Storage Temperature Value 350 350 6 500 625 150 -55 ~ 150 Units V V V mA mW °C °C • Refer to 2N6515 for graphs Electrical Characteristics Ta=25°C unless otherwise noted Symbol BVCEO BVCBO BVEBO ICBO IEBO hFE Parameter * Collector-Emitter Breakdown Volta [ ... ]
2N6517 PDF Datasheet Download
