LM317 Adjustable Voltage Regulator. Most useful regulator ever.

The LM317 adjustable voltage regulator is by far one of the most versatile regulators ever. If you need a precise voltage somewhere in the range of 1.2 volts to 37 volts, this regulator is for you. A simple resistor network allows you to select the output voltage, and with the capability of driving up to a 500ma load this is one excellent regulator.