Circuit :  QS
Email  :  qs@quantstuff.com
Notes
This circuit is a single transistor flyback (Joule Thief) circuit that features a third coil. With it, flash duration and brightness is much enhanced, without resorting to large value capacitors. The performance can be seen in the following Videos (on Youtube):

http://www.youtube.com/watch?v=tgcYcPDbwNo

http://www.youtube.com/watch?v=wcHaE4rv64M

http://www.youtube.com/watch?v=2HLDPaO9oDM

The last is meant to upgrade a Solar Garden Light and demonstrates automated daylight power-off - with just an extra diode and resistor. You can also find more information about this and my other circuits here:

http://quantsuff.com