EL wires are wonderful for light installations and photography tools. They come in many different colors and sizes. There are relatively dim ones and pretty bright ones. Recently I found a shop that also sells some called "chasing EL wires".
Since the examples looked quite interesting I ordered some to try them out. It turned out that these chasing wires are three normal wires woven together and are controlled by a special driver. This causes an effect that looks much like the wire is alive, the light is crawling in one direction along the wire. The driver I ordered also has a control to reverse the direction and change speed from a slow crawl to a fast flicker.
The only problem was that these wires are only available in certain lengths with pre-attached connector, so if you need a custom length for some cosplay prop or the likes you have to cut them. Cutting the wire is no problem at all, you just need to re seal the end to prevent damage and moisture getting inside. It probably does not hurt much if you only cut small pieces away, but when you cut a large piece it would be nice to use the cut off piece some place else.
After some research and contacting a few places that had these wires it seems no one really knew how these wires are soldered to the connector. So I decided to do some testing on my own to find out how they are connected and write this tutorial so others looking for the same information get an idea how to do this.
Step 1: What Is an EL Wire and How Can It Be Chasing
EL wire is short for electroluminescent wire, which means that the wire. These wires are made of copper wires coated with phosphor and wrapped with another fine copper wire (sometimes als called corona wire or angel wire) which glows when an alternating current is applied to these two copper wires. If you want to know the exact science behind this check out the very good wiki article on them.
I already found out that the chasing wire is made out of normal wires woven together. The one I use in this instructable consists of three normal wires, but I also found some that were made out of nine wires of which pairs of three were connected together. The soldering of those is more or less the same, you just need to connect the three wires that belong together in parallel.
To find out how these wires are connected I cut open a wire and separated the strands. Each strand is coated with another PVC sleeve for protection and to set the color. This sleeve also has to be cut away. Under the sleeve you will find the fine copper wires and the phosphor coated central wire.
Step 2: Figuring Out the Circuit
I had some ideas on how the wires could be connected but it is always better to make sure. So I used a digital multimeter set on connection mode (the mode where it beeps when the two parts you touch the probes on are connected) and probed the parts of the EL wire and the points where the connector is soldered to the controller board.
Using this method I found out that the fine wires were all connected together which makes sense since these are the most intricate and delicate ones to solder to some connector. Putting these together makes the whole bundle a little more stable and robust. The other connections are soldered to the three center wires. So the controller creates the chasing effect by swapping through the three wires and turning them on and off one after the other.
Now that we know how the circuit of the wires looks like we can solder the copper wires to some cables to create a new connector. For this all you need is:
- copper tape
- solder iron and solder
- shrinking tubes
Step 3: Preparing the Center Wire and Solder the Corona Wires
First you need to scrape off a little bit of the phosphor (excuse the first photo, focus was a bit off here). Please be careful since I don't know how dangerous the stuff is. I used gloves and cleaned all the dust away afterwards to make sure. You only need to clean the tips of the center wire to expose enough to solder cables on. Leave enough of the phosphor on the wire to have some insulation.
Next wrap little piece of copper tape around the parts of the wires that are still covered with the PVC tubing. Leave some room between the copper tape and the end of the PVC tubing to create a small zone that can be used for insulation too.
Next solder all the corona wires together on the copper tape. We use copper tape here because it creates a great surface to put sone solder on.
Step 4: Solder the Center Wire and Insulate Them
Next solder some cables to all three center wires where the phosphor has been scraped off. Take care that they don't touch and you don't solder them together. The corona wires should be way out of reach too.
After soldering the cables on the center wires put thin pieces of shrinking tube around them. The shrinking tube should cover the solder point and go all the way down to the copper tape. This way it will also cover the exposed phosphor from this wire up to the point where it goes into the PVC tubing thus preventing that the center wires are able to touch in any way.
Step 5: Cable for Corona Wires and Final Insulation
After all the center wires are soldered to the cables and safely insulated you can solder the wire for the corona wires on the copper tape as well. It is a good idea to do this last because it will be in the way when soldering the center wires (and the whole thing is small and fiddly enough as it is). I used a white cable here to know which one is the one for the corona wires to make it easier to connect them to the controller board.
Make sure all connections are good using a multimeter and then put a larger piece of shrinking tube around the whole connection covering the other shrinking tubes and a small part of the outer PVC tubing. This way you make the connection more stable because the shrinking tube takes away some stress from the solder connections when you move the EL wire around.
Step 6: Conclusion and Sources
Now that you have cables soldered to all parts of the chasing EL wire you can connect the cut off piece by whatever means you want to the controller. This way you can oder any length you like and cut pieces from the wire as needed.
The best shop for these kind of EL wires is EL WireCraft in the UK. They sell ultra bright EL wires and also chasing wires made out of these ultra wires. If you know more shops that sell chasing wires leave links in the comments.
I hope this instructable helps others who like to do some projects with chasing wires.