LM317T Voltage Regulator with Pass Transistor

Day 1: Voltage Regulated, Current Limiting, Power Supply Regulator. Takes unregulated 15-25 volt supply and provides a regulated 2.7-13.8 volts with selectable current limiting. I suggest building it with a 20-30 mA limit, and a larger one, several hundred mA, or whatever your transistor can dissipate in the worst case.



http://www.youtube.com/watch?v=ZMctZNINLYc&hl=en