This is one of the regulator types.
Part number : 7805, KA7805, LM7805
Function : 3-Terminal 1A Positive Voltage Regulator
Package : TO-220 Type
Manufacturer : Fairchild Semiconductor, National Semiconductor
7805 is 5V, positive voltage regulator. The 7805 of three terminal regulators is available with several fixed output voltages making them useful in a wide range of applications. One of these is local on card regulation, eliminating the distribution problems associated with single point regulation. The voltages available allow these regulators to be used in logic systems, instrumentation, HiFi, and other solid state electronic equipment. Although designed primarily as fixed voltage regulators these devices can be used with external components to obtain adjustable voltages and currents.
The KA78XX/KA78XXA series of three-terminal positive regulator are available in the TO-220/D-PAK package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.
1. Output Current up to 1 A
2. Output Voltages: 5 V
3. Thermal Overload Protection
4. Short-Circuit Protection
5. Output Transistor Safe Operating Area Protection
Reference page : http://www.datasheetgo.com/7812-voltage-regulator/
7805 Datasheet PDF
Download Datasheet PDF : [ 7805.PDF ]