Solar powered fairy lights

  
Yes, I'm going through a solar powered phase right now. I'll have used up the parts I bought from allelectronics.com soon enough & will have to move onto pastures new.

My lovely lady suggested it'd be nice to have some twinkling fairy lights in the kitchen; ideally, ones that didn't need to be plugged in to the mains. The simplest solution would have been to use a battery pack, but our kitchen gets a fair bit of light &, like I said, I'm in a solar powered gadgetry phase right now...

My ebay habit has brought me some colour changing LEDs (before I knew exactly what they did). These look like normal LEDs (two leads) but cycle through a few colours over the course of 15 seconds or so. I figured these would be perfect for the project, so I dug out 4 working ones (using the LED tester I posted about previously).

There are very few components for this (if you count the solar-panel/charger as a single component): 1 solar charging circuit, 4 colour changing LEDs, an Altoids tin, some wire and I used a couple of neodymium magnets to secure the tin onto the curtain rail in our kitchen.

The first thing to do is to cut the LED leads from the solar-charging circuit, this is where we'll attach the wires for our own lights. I also cut down the plastic 'pins' which hold the circuit board in place; this was to make the assembly fit nicer in the tin (and as an excuse for me to try out some new cutting disks for the Proxxon).

I then cut two strands of wire (about 1 1/2' each of red and black), marked where I wanted to place the LEDs/lights on the wires and striped away the insulation around these points. I ended up melting the insulation away with a soldering iron and then using a knife to scrape off the excess plastic. There must be a much better way of doing it.

Soldering the LEDs onto the wires was a little awkward, especially since I cut the LED leads down to about 1/3 cm to keep them close the the wires. I'm glad I decided to only put on 4 for this prototype! Hmmm... thinking about it now, I should have left the leads on and bent them around the other wires to hold them in place whilst soldering them, doh!

After soldering the LEDs, I drilled a couple of small holes in the Altoids tin, threaded in the two wires and soldered them onto the solar charging unit.

Slide everything into place and there we go:

My better half has been making lots of playdough for some lovely projects (see: Dinosaur Island and playdough rain table) as a result, we've used up a lot of food colouring. It turns out the bottles make quite good LED diffusers. The picture below shows the Fairy Lights in front of our kitchen window. I used two magnets to make the tin secure (the magnets are on the inside of the tin). I also ended up taking the lid off the tin and securing the solar panels in-place with a couple of elastic bands.

Solar powered fireflies

I've been wanting to make something solar powered for some time & figured the firefly kit would be perfect to upgrade to solar power.

I just came across some cheap, second hand, solar powered light fixtures from allelectronics, which is a great place to pick up bits and bats for your electronic projects. Here's the actual solar lights I bought - solar-cell w/charging circuit. As the description says, they come with two solar panels, an LDR, a charging circuit (including - old - batteries) and some LEDs (one LED with this particular one and three with a different product).



As you can see from the pictures, all the components are easily acessible; these seemed perfect for hacking.

My first attempt was pretty simple, I just de-soldered the battery wires from my old JarOFireflies project, snipped the leads to the LED on the solar light kit and soldered the two kits together (the leads to the LED actually have a + and - designation printed on the board).


The LED wires are solid core and quite thick so there's no worry about them snapping under the strain and it made positioning the firefly board easier too. Speaking of which, I cut down the board to a more reasonable size for this project.

I didn't know if the batteries on the solar kit were duff so I left the hybrid out in the sunshine for a full day to charge then brought it indoors to see if it works:


And it does! What a pleasant surprise for something to work first time!

I think I'll cut a hole in the original jar's lid and place the kit in it more securely. Might be nice just to put it out in the garden to confuse the next door neighbours cats who seem to prefer our back yard to their own...