LM317T Voltage Regulator with Pass Transistor

This is a car ignition coil driven modified CFL light. The circuit is only two very small transistors. The circuit self oscillates by feeding back a pulse signal gathered by a thin wire that is wrapped around the base of the ignition coil. A step down adjustable voltage regulator is used to control the power coming out of a small AA battery pack. A wave form is shown on a oscilloscope. The device is running on 4.5 volts (regulated) at 20 milliamps.



http://www.youtube.com/watch?v=2ySO2NXh3jw&hl=en