This part is a kind of semiconductor called 7912CT.

Function of this product has L7912CT.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

® L7900 SERIES NEGATIVE VOLTAGE REGULATORS s s s s s OUTPUT CURRENT UP TO 1.5 A OUTPUT VOLTAGES OF -5; -5.2; -6; -8; -9; -12; -15; -18; -20; -22; -24V THERMAL OVERLOAD PROTECTION SHORT CIRCUIT PROTECTION OUTPUT TRANSITION SOA PROTECTION DESCRIPTION The L7900 series of three-terminal negative regulators is available in TO-220, ISOWATT220 TO-3 and D2PAK 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; furthermore, having the same voltage option as the L7800 positive standard series, they are particularly suited for split power supplies. In addition, the -5.2V is also available for ECL syste [ ... ]

7912CT PDF Datasheet Download