Hand Cranked Flashlight Mod plus Joule Thief

Step 5 Adding a Joule Thief

This mod is more challenging and requires that the circuit be reverse engineered in order to determine how to replace components.

To add a joule thief the whole circuit between the switch to the LEDs must be modified.

The first thing I noticed when I reversed engineered the circuit is that The LEDs are in parallel. The joule thief is able to run three LEDs in series. I rewired the LEDs by scoring the circuit then soldering jumper wire.

The second major modification, is to remove all the diodes and resistors between the LEDs and switch then adding a standard Joule thief in place.

The result was a brighter flashlight that lasted 1/2 the time as the circuit without the joule thief. Adding more capacitance will increase the run time of the flashlight.

However, it does not bother me cranking the flashlight every few minutes or so. The light is brighter than the factory original.

Comments

[bahi]

Very useful, thanks!

[Biotele]

welcome