the l7800 series of three-terminal positive  regulators is available in to-220, to-220fp,to-220fm, to-3 and d2pak packages and  several fixed output voltages, making it useful in a wide range of applications. these regulators can provide local on-card regulation, eliminating the distribution problems associated with single point regulation. each type employs internal current limiting, thermal shut-down and safe 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 toobtain adjustable voltage and currents.