This part is a kind of semiconductor called 78S05.

Function of this product has L78S05.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

L78S00 SERIES 2A POSITIVE VOLTAGE REGULATORS . . . . . OUTPUT CURRENT TO 2A OUTPUT VOLTAGES OF 5 ; 7.5 ; 9 ; 10 ; 12 ; 15 ; 18 ; 24V THERMAL OVERLOAD PROTECTION SHORT CIRCUIT PROTECTION OUTPUT TRANSISTOR SOA PROTECTION DESCRIPTION The L78S00 series of three-terminal positive regulators is available in TO-220 and TO-3 packages and with several fixed output voltages, making it useful in a wide range of applications. These regulators can provide local on-card regulation, eliminating the distribution problems associated with single point regulation. Each type employs internal current limiting, thermal shut-down and safe area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 2A output current. Although designed [ ... ]

78S05 PDF Datasheet Download