EL Wire Neon Sign Pt. 2

Heres part 2 of the EL Wire Neon Sign post from earlier.

 

Background and Direction:
Instead of re hashing the information in part 1 I’m going to concentrate on what I did differently.

So for this sign I wanted to add some motion to the sign so I decided to make a Mr. Boh neon sign. For those who don’t know what that means he is a beer mascot from a formerly Baltimore based beer company, National Bohemian. There is still a large neon sign where the beer used to be brewed in downtown Baltimore. I was inspired to make it wink after I saw one that did in a bar.

There lies the difficulty, EL wire runs off an AC signal from the inverter and starting and stopping that requires additional hardware along with some sort of logic signal to time the action. While the last sign was static and was rather light on the electronics, this one has a control board and more complicated wiring. Lets get to it shall we?

 

BOM:

EL wire – Your choice of where to get it. Adafruit sells it, as do a whole bunch of people on amazon. I chose the latter for cost.

EL wire inverter – I bought this one from amazon but the wire I bought also came with battery powered ones. Up to you.

EL wire splitter – Depends on your setup but I needed one because of my 2 different colors.

EL Wire Connectors

Copper tape – for splicing the connectors on to the bare EL wire.

Power Supply for inverter – I had a 12V 1 or so Amp supply laying around which was probably overkill

Switch – Self explanatory. Also not completely necessary.

Epoxy – I used E6000 which is available at most department stores or online.

3/16″ MDF- For the face of the sign. Big enough for your design.

1″ Diameter Wood Dowel – To stand the sign off the wall

Felt Furniture Feet Pads – To protect the wall from your sign

Black (or whatever you like) spray paint – Black provides a nice contrast with the lights so I prefer it.

 

Electrical Parts:

Perf Board – I used one of these from amazon.

1 x 555 Timer – Very useful chips. I bought 50 a while back from amazon

2 x Optoisolators-  Mouser

2 x Triacs – Mouser

1 x 100uF Electrolytic Capacitor – anywhere

2 x 4.7k ohm 1/4W Resistors – anywhere

1 x 1k ohm 1/4W Resistor – anywhere

1 x 330 ohm 1/4W Resistor – anywhere

3 x IC Holders – Optional

1 x DC Jack – Make sure it fits your power supply

22 Ga wire

 

Tools:

CNC router with 1/8″ ball nose bit –  Check your local makerspace for one.

Sandpaper – Eliminates rough edges.

A bunch of painters tape

Syringe – For applying the epoxy. If you use epoxy that needs to be mixed you may have a small enough nozzle to apply it accurately but the E6000 needs it to be accurate.

Soldering iron and solder

 

Step 1: ‘Digital Stuff’

Find/make your pattern like you did last time. Some notes about this:

EL wire can pinch into some tight places but it: A) dosen’t really like it and B) is better practice to give it a bend radius. When I made my vector path from a jpeg in inkscape (there are a ton of tutorials online for how to do this) I edited it to eliminate sharp corners and give the wire a place to bend.

Plan out what you want moving here too. The following photos show what I intend to do with this sign.

My DXF for the router to cut. Note I cut both stages of the eye movement
Measuring how much wire I need

Step 2: ‘Cutting Stuff’

Same settings as the last post. Here are cliffnotes:

Use MDF and paint it

Use a 1/8″ ball nose mill and cut 1/16″ deep

Drill 1/8″ holes at the ends of the grooves for ‘sewing’

Routing out the groove and outer edge of the sign

Step 3: ‘Painting’

Very self explanatory.

The painted Mr. Boh

Step 4: ‘Weaving and Gluing’

Weave the wire just like in part 1. What I would do next time is weave the entire sign even the separate circuits of wire and cut what is supposed to be separate after it is glued down. This way you don’t have to wait for glue to dry before moving on and you can do it all at the same time.

Step 5: ‘Board Construction’

Heres the biggest change. The brains of the sign.

The main control is a 555 timer running in astable mode with an approximate 50% duty cycle. That was the easy part to engineer for me. The harder part was switching the AC load that EL wire needs to glow.

Luckily some googling led me to a pretty cool website with the exact answer I needed. He had a schematic in the user manual which was what I ended up using. If you have a larger project in mind consider purchasing his kit that can control up to 8 strands simultaneously. Since I only needed 2 I decided to make my own board.

The idea is the logic signal turns on the LED in the optoisolator which turns on the triac side which turns on another triac that drives the wire. I think you can eliminate the triac and just use the optoisolator if you want but I think this way is safer and more robust.

The other problem was how to make the lights alternate. My original thought was to use a logic inverter which would require 5V input not 12V that my inverter for the EL wire runs at. This would definitely work but instead I used different resistor values and arranged the LEDs  in the optoisolator differently.

Anyway, below is the schematic and photos of my completed board. Plus a GIF from testing!

Blinking Brain Schematic
Testing my circuit
The assembled PC Board

Step 6: ‘Wire up and Finishing Touches’

So in the case of my sign I have two unconnected sections of EL wire at the moment. I want to plug these into the leads I have coming off the board I made. So we need to solder the connectors to the wires. Adafruit has an excellent tutorial for this which is exactly the method I used to connect my wires. Also, you don’t necessarily need a connector. You could use some 22 Ga wire and solder directly to the board. If you are worried about the aesthetics more than I am by all means do that and avoid the rats nest you will see later. Speaking of rats nest, hot glue is sufficient for securing wires and your board to the back of your sign.

Wire up

Now for mounting. To try something different I used 1″ wood dowels cut to 1.5″ to stand off the profile I cut. Since the sign wasn’t a rectangle like last time I couldn’t make a box. This method gives you freedom to make whatever shape you want which is a very cool thing to have in your back pocket.

Gluing the post to the sign
Camping the posts during gluing

I had to mount the power jack and switch somewhere so in two of the dowels I drilled a hole for the jack and milled out a rectangle on my horribly inaccurate, but useful in a pinch desktop dremel mill.

The power jack inserted into the post
Milling out the switch hole
The switch assembled in the post

To hang the sign I drilled a hole in each of the remaining dowels large enough for a #6 screw. Feed picture wire through the hole and screw it down. It is good practice to drill your holes in line with where the wire will go so you avoid twisting the glued face of the dowel.

Secure the picture wire with #6 screws
How I hung the sign

Finally glue a piece of foam to the back of your sign to eliminate the whine of the inverter and glue the inverter to the foam. This gives the inverter enough degrees of freedom to vibrate the free air rather the sign, making the whine much quieter.

The inverter glued to the damper to eliminate noise. I used foam for this

Boom! You’re done!

The motion of the finished sign

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