Push Fit LED Moodlamp

This is a cool project to reuse an old mobile phone charger. Instead of throwing it away, we're going to turn it into a cool moodlamp!

This version uses a cool wooden circuit board to make assembling the leds and the resistors easy. It's great if soldering irons aren't viable, or you need a quick turn around.

If you got a kit from the Bristol mini maker faire, here's what's inside.

Otherwise if you want to try an led moodlamp, here's an instructable that doesn't need a laser cutter!

Or, if you want to try a laser cut circuit board - the files are here. If your material is not 3mm, you'll need to use openscad to regenerate the dxf. Then you'll also need a couple of leds and some resistors.

an old phone charger you don't mind cutting the plug off,
an old roll of tape

use a pair of wire cutters (or scissors if you don't have any) to cut the end off the phone charger

we need about 5 cm of individual wires, so strip back the outer layer of the cable. Inside, there will probably be 2 wires of different colours. Here they are black and white. If you have more than 2 wires, don't worry.

Strip the ends of each of the wires inside, so there is about 1cm of bare wire. Twist the strands together to make them neat.

thread the phone charger cable through the holes on the wooden circuit board. Then, if the cable is yanked, it won't break our circuit.

Leds don't like too much current, or they blow up. And they only work one way round. So we need to find which way round they go, and which resistor to use.

The kit gives you 2 sizes of resistor, so you've got some options. Use the picture on this page to work out the values in your kit. We'll try the biggest value first, and then if the led is too dim, we can use the lower value.

Start with one led, and hold one of the phone charger wires on one leg, and the other phone charger wire on the leg of the resistor. Touch the other leg of the resistor to the other leg of the led and see if it lights up. If not, try turning round the led. You can find out why leds need to be the right way round here.

Make a note of which wire connects to the shorter (negative) leg of the led. That's the negative wire. The other wire is the positive wire. In this case, the black wire is negative, and the white wire is positive.

If your phone charger has more than 2 wires, you'll have to try every combination until you find it!

If the led is too dim, then you can try the lower value resistor. The lower value lets more current through, which makes the led brighter. If the led is too bright though, you'll notice the resistor getting hot, and the led will probably die within months rather than years.

Put the led's short leg (negative) in the small hole and it's longer (positive) leg in the big rectangular hole. Put the resistor in the hole shown.

Turn the board over and twist together the wires

Now go back to step 5 to get the other led's resistor.

Then add the led and the resistor as before.

The wooden circuit board works by using a push fit plug to hold all these wires together.  Make sure you get the positive wire (if you've forgot, you can always test first), then hold it and the led's legs in the middle of the plug hole.

Push the plug gently on top, and make sure all 3 wires still in place!

Then push the plug with both thumbs all the way in to the hole, it should click into place.

Do the same with the second plug and the negative wire.

Plug in the phone charger and both leds should light up! If not, then some of the wires must be the wrong way round. If you're careful you can get the plugs out by gently squeezing them from the back, but they're not really designed to be used twice. They might need gluing in place the second time.

cut a slot in the tape reel to let the cable out.

Now you're ready to add a shade. Tracing paper, felt pens, thin paper, hole punches, paint, whatever you fancy.
See here for some inspiration.