Joule Thief KitThis kit is a version of the popular Joule Thief Circuit, it uses power that would normally be wasted from used AA batteries to power a bank of 6 Hi Brightness white LED's. Although this circuit is low power, it produces enough light to be a usable torch. (It produces a similar amount of light as the LED torch on a smartphone).

For the theory of how the circuit works, take a look at this wikipedia article: https://en.wikipedia.org/wiki/Joule_thief

Kit Contents

2 x 4.7uF Electrolytic Capacitors

1 x 470pF Ceramic Capacitor

1 x 2N4401 NPN Transistor

1 x Driver Stripboard (7x7 holes)

1 x LED Stripboard (5x7 holes)

6 x Hi Brightness White LED's

1 x 1N4531 Fast Diode

1 x 4.7K Resistor

0.5M Twisted Pair Wire

1 x Toroidal Ferrite Core

1 x AA Battery Holder

←-Schematic

Tools Needed:-

Soldering Iron and Solder

M4 drill bit (can be slightly larger)

Side Cutters

1) Cut Tracks on the LED Board (Smaller board)2) When finished, it should look like this.

3) Mount the LED's, Make sure all the LED's are the same way around, e.g. for a group of 2 of LED's,

poking through the Stripboard, should be Longer leg, Shorter leg, Longer leg, Shorter leg.

4) Solder the middle strip and the outer strips 5) Solder the other legs of the LED's and join the 3 centre tracks with solder.

Remove the centre LED legs, and one of the Minus legs (it's safer to do this at the very end, just before you mount the LED board to the Driver board, so the correct leg is removed.

6) Wind the Transformer, Wind as many turns as you can through the toroidal ferrite core, with the wire provided, 10 is the minimum, 12 is the maximum possible.

7) Finished Transformer 8) Attach the spare wire from the transformer to the battery holder.

9)Mount Passive Components to the Driver Board first (Resistors / Capacitors / Transformer)... The diagram view is looking from the track side of the board (e.g. components are on the other side)

10) Mount the Active Components (Diode and Transistor)

11) Mount the Battery Holder.

12) Attach the LED Board to the Driver Board. 13) Insert a battery and look at the pretty LED's.