AP1117E50G-13 is a 5V low dropout positive regulator with 1A output current at 6.4V to 18V input supply.
This L293D is a Quadruple Half-H Drivers to drive the inductive loads (relays, DC and stepping motors).
This SP232EEP is a 2x driver and 2x receiver pairs that meet the specifications of RS-232 and V.28 serial protocols with enhanced ESD performance.
This ULN2003A is a 7x high voltage, high current darlington arrays with common emitters. Each channel rated at 500 mA.