The LM78XX series of three terminal positive regulators are
available in the TO-220 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.