This part is a kind of semiconductor called L7805AC.

Function of this product has PRECISION 1A REGULATORS.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

L78 Positive voltage regulator ICs Datasheet - production data Features  Output current up to 1.5 A  Output voltages of 5; 6; 8; 8.5; 9; 12; 15; 18; 24 V  Thermal overload protection  Short circuit protection  Output transition SOA protection  2 % output voltage tolerance (A version)  Guaranteed in extended temperature range (A version) Description The L78 series of three-terminal positive regulators is available in TO-220, TO-220FP, D²PAK and DPAK packages and 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 embeds internal current limiting, thermal shutdown and safe area protection, making [ ... ]

L7805AC PDF Datasheet Download