BC517 is an NPN darlington transistor manufactured in TO-92 package, a darlington transistor is a pair of combined two BJT transistor connected with each other in a wiring called darlington pair in a single package for obtaining high gain and to switch ON higher current on very small base current.
Package Type: TO-92
Transistor Type: NPN Darlington
Max Collector Current(IC): 1.2A
Max Collector-Emitter Voltage (VCE): 30V
Max Collector-Base Voltage (VCB): 40V
Max Emitter-Base Voltage (VEBO): 10V
Max Collector Dissipation (Pc): 625 miliWatt
Max Transition Frequency (fT): 200 MHz
Minimum & Maximum DC Current Gain (hFE): 30000
Max Storage & Operating temperature Should Be: -55 to +150 Centigrade