Dollar Store Joule Thief!

Important Note* If you start to read this and wonder what is so cool about turning a flashlight into a different flashlight Google "Joule Thief". This is an instructable for turning a flashlight into a low source voltage more complicated flashlight!

The basic idea is that you are taking a voltage (dead battery or single battery) that wouldn't normally be able to drive an LED and using a simple boost circuit make it able to drive one or more LEDs (*efficiency is pretty low).

One day I was in need of a variety of white leds for a project. My local shack is a a rip off and the nearest eletronic component shop is pretty far away from my house. There is a dollar store up the road and I knew that they had a few different led flashlights I could scavange parts from in a pinch. One of the led flashlghts I bought was a dual purpose model that would terrify potential attackers with an annoying piezo if you were the victim of muggers with sensitive ears. This instructable is based on that particular flashlight/attack prevention tool thingy.

Step 1 What you will need...

1) Either one of the flashlight sirens below will work just fine for this. The components inside are identical.
2) Soldering iron
3) Small phillips screwdriver
4) Solder
5) Wire cutter/stripper
6)About 20 or 30 minutes of quiet time

Comments

[brandegor]

Oh yeah - and what about the capacitor? Is that in the circuit and if so, what is its purpose? Thanks.

[brandegor]

It looks like there is a coil of bare copper wire there - what is it for and how does it fit into the circuit? Very cool project - nice component hunting!

[Anthony312]

nice doodle there...

[Skill1137]

Thanks!! that helps alot!

[aromaoftacoma]

Sorry about that. I just added a quick drawing of how it is soldered up to step #4. When I physically assembled it I cut the leads very short and piled everything on the end of the transformer so pictures might confuse the process more. I attacehd a closer pic of the end result as well.

[Skill1137]

Can you please post some more photos of the this finished circuit, its hard to see the connections and would help some of us get the feel of the circuit while we put it together.

[aromaoftacoma]

Yeah you have to take it apart. It's set up as a whole different circuit inside(piezo driver). You could leave it assembled and use it as a flashlight it just wouldn't be very nerdy of you.

[TOCO]

Dude its only a dollar. Does it matter if you need to dissasemble it?

[______]

Do you have to dissasemble it