Friday, December 19, 2014

Scavenging leds from Christmas decoration


Well it's that kind of the year again. Christmas is arriving. That means that the shops are full of christmass decorations. And that is something worth looking into.

Our local pennyshop called Action stocks lots of christmas decorations which are bundles of leds powered by batteries. The have them in all sorts but these are the most interesting for our purposes:

Each package consists of 40 bright leds. Some packages only contain blue leds, others only red leds and some packages consist of 40 leds being 10 red, 10 blue, 10 green and 10 yellow leds. These packages cost less as 2 Euro. Meaning you will have 40 really bright leds for 2 euro being 5 cents pro led. That is a bargain. So I bought multiple packages.

There is an added bonus even:
The leds are supplied with a battery box that accepts 3 AA batteries and has an on/off switch. We can use that as a power source for some of our future projects !!

To scavenge the leds we start with the last one in the chain. Follow the lead and cut the wire as near as possible at the previous led:



Next step is to strip the wires and test the led with a button cell like the CR2032 which supplies 3 volts. You can also test the leds with an AA battery.

Now mark the + side of the led with a marker so you'll know what the Anode and Cathode are when you need them later.

Now as you see at the next picture the leds are captured in some kind of plastic holder.

Fortunately you can carefully bend that plastic wrapture as it is kind of flexible. This makes it easy to use the leds in smaller (thin) housings for your projects.

I stock the leds in separate plastic bags sorted by colour which makes it easy to find the right led for my project when needed.

So this makes it easy to get your yearly supply of really bright leds at a very low price. I have used these leds in several of my projects like my - Walking Safety Larson Scanner Lights- and an Electronic Hourglass. Both projects will find a place on the site in the future. So keep on reading.