Family Joules at Derby Makers

Last night I attended a fantastic workshop at Derby Makers, run by Graeme Smith and his daughter, where we made a legendary piece of hackery - The Joule Thief. This is something I've seen all around the internet but never got around to gathering the parts for. Probably my favourite incarnation saw the JT fused with sew-able circuits to make the "Cat Burglar". 

Bat Burglar would have been more appropriate, but probably wouldn't have made such a cute construct. For those who have never heard of a Joule Thief or have but don't know what it is. A JT (I've typed it in full enough!) is a circuit that allows you to run an LED on a nearly dead battery. For those that don't find that amazing, consider that the LED I used runs from 3.4V and a fully charged AA battery gives at best 1.5V. For those that don't find that amazing see here (might be more your sort of thing).

It was one of the busiest Derby Makers sessions that I have attended and there were lots of new faces eager to get their hands on a JT kit. Comprised of a lovingly etched PCB, battery holder for the nearly dead battery, a transistor (2N3904), a switch, a resistor (1K) a ferrite bead, a long length of magnet wire and perhaps most importantly an LED. 

A keen group had arrived early and started to make headway on their JTs, which was fortunate as it freed up Graeme to help a second table and get them winding their ferrite cores with magnet wire (the first step). The bead comprised the complicated part of the procedure, but this was all nicely explained and had a great diagram on the second page of the instructions.

Once the bead was wound and the ends identified we got onto some soldering (and eating of biscuits).

What is that excellent piece of product placement, er I mean PCB holding equipment, I hear you cry? That is the Panavise Jr. Available from phenoptix.com. Sorry about that, it's the first one in four blogs though. 

The soldering stage was a blur as the red mist descended and the camera was forgotten. I was soon the proud owner of a working JT!

All that remained for the workshop was to discuss how the JT works. Which hopefully will follow in another blog post. 

But to summarise, it was a great evening at Derby Makers where people of all ages and abilities made something together, helped each other and enjoyed discussing and showing off what we'd made. If this is something that would interest you then please come along to an event! They run every second Tuesday at the Derby Silk Mill. If you're not able to make it Derby Makers why not see if there's a hackspace in your area?