Eric's Arcana and RiderX

We got the lights up this weekend. Well, most of them – one of the main ones (see pictures here) happens to be on the gate on the north side of the house, and this year we are replacing a deck on that side our only access is through the gate. So… the 14’ high 12’ wide tree of lights is staying in storage this year. Sigh.

I am, however, in the midst of working on a new project – a juggling snowman.

I wanted to try something different and had been looking for a project to do with EL wire. EL wire is a little like a flourescent light – there is a high voltage alternative current that excites a phosphor that puts out light. The natural color of the el wire is an intense aqua color – the different colors come from the plastic jackets around the el wire, which means the colors are a slightly different intensity.

To create the drive current, you need something that can put out about 120VAC at 2KHz or so. That means you need an inverter to take the DC power and create the high-voltage to drive the wire.

The downside? Well, the most annoying downside is that there is a center conductor on the EL wire, and then two tiny wires (corona wires (no relationship to the beer)) that wrap around the core. Not just tiny, really really tiny. Take a piece of stranded 22 gauge wire, and separate the individuals strands. The corona wire is much tinier than each of the individual pieces. And I have 48 separate segments to attach to wire, which took me 8 hours or so. After that, each end gets a bit of hot glue and the some heatshrink tubing.

The design will attach to a 2’x4’ piece of 1/4” plexiglass I bought from TAP plastics. To figure out where everything will go, I took a piece of paper and did the layout of all the elements full-size onto it. The plexiglass goes on top of that, and then all the pieces of EL wire will get hot glued to the plexiglass.

It looks like this:

Here’s the main body lit up:

The aura around each of the wires is the light reflected off of the white paper that is underneath the plexiglass. I like the effect, so I’m going to paint the back of the plexiglass white.

And the hat, one arm, and one ball.

The round ball is red but renders orange on my Canon because of the spectrum of the light. The dots around the circles are where the hot glue holds the circles down. If you look closely at an enlarged version, you’ll see that there are 8 yellow arms coming down – those are the 8 positions of the arms on the right side. The quality is poor because it’s shot at ISO 12800 on my 7D.

Here are the vital stats:

• 16 channels of animation.
• 8 channels devoted to the snowman’s body.
• 8 channels devoted to a 3-ball cascade juggling animation.
• atmega8515 to control the animation (way overkill but I had it lying around).
• Panasonic AQH2223 logic-level triacs for switching.
• EL wire and drivers form elwirepros.com.

For software I’m going to adapt the code I wrote for the 15 channel big tree light display, though it will be simpler because I’m not implementing dimming.