This post explains for the voltage regulator.
The Part Number is 7805A.
The function of this transistor is 5V, regulator.
Manufacturer: Estek, WingShing
Preview images :
This 7805A series of fixed-voltage monolithicintegrated-circuit voltage regulators is designed fora wide range of applications. These applications include on-card regulation for elimination of noise and distribution problems associated withsingle-point regulation. In addition, they can be used with power-pass elements to make high-current voltage regulators.Each The internalof these regulators can deliver up to 1.5 A of output current. limiting and termal shutdown features of these regulators make them essentially immune to overload.
1.Output Current in Excess of 1.5A (PD˚ 15W)
2. No External Components Required
3. Internal Short Circuit Current Limiting
4. Internal Thermal Overload Protection
5. Output Transistor Safe-Area Compensation
6. Output Voltage Offered in 4% Tolerance […]
7806A : 6 V
7807A : 7 V
7808A : 8 V
7809A : 9 V
7810A : 10 V
7812A : 12 V
7815A : 15 V
7818A : 18 V
7820A : 20 V
7824A : 24 V