Quentin
Get flash to fully experience Pearltrees
In the November 1999 issue of EPE (Everyday Practical Electronics), a small and intriguing circuit was published in the Ingenuity Unlimited section by Z. Kaparnik.
Make a Joule thief.
This page presents general information and tips for using the LM555 timer and devices with other letter prefixes.
LM555 Timer Circuits
Using the completed board The completed board may be driven by voltages between .8 and 3 Volts. While the basic design goal was ‘candle like light from a single cell’, the values used were chosen to allow safe operation from 3 Volts so you can, for example, use it to ‘drain the last bit of energy’ out of used Lithium based cells from flashlights. This means that you can also drive it from a fresh 123 cell at full brightness (for 16 hours or so) or two NiMH, alkaline or other cells in series.