The LM78XX series of three-terminal positive regulators is available in the TO-220 package and with several fixed output voltages. Each type employs internal current limiting, thermal shut-down, and safe operating area protection. If adequate heat sinking is provided, they can deliver over 1 A output current. Although designed primarily as fixed-voltage regulators, these devices can be used with exter-nal components for adjustable voltages and currents.