7812

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7812 is an integrated three-terminal positive fixed linear voltage regulator. It supports an input voltage of 18 volts to 35 volts and an output voltage of 12 volts. It has a current rating of 1 amp although lower current models are available as of 2006. Its output voltage is fixed at 12 volts. The 7812 also has a built-in current limiter as a safety feature. 7812 is manufactured by many companies, including National Semiconductors and Fairchild Semiconductors. The 7812 will automatically reduce output current if it gets too hot.

It belongs to a family of three-terminal positive fixed regulators with similar specifications and differing fixed voltages from 8 to 15 volts. These are usually packaged in TO220 chip carriers, but smaller surface-mount or larger metal can packages are also available. The last two digits represent the voltage; for instance, the 7812 is a 12-volt regulator. The 78xx series of regulators is designed to work in complement with the 79xx series of negative voltage regulators in systems that provide both positive and negative regulated voltages, since the 78xx series can't regulate negative voltages in such a system.