Building EL Displays On A PCB

ELElecrolumiscent displays have seen a huge swing in popularity recently, but only in limited forms like EL wire or flat EL panels. You can, of course, cut and bend these wires and panels to suit any purpose, but custom shaped EL displays are just the bee’s knees. They’re not hard to fabricate, either: with cheap custom PCBs, all it takes to make custom EL panels is just a few chemicals.

[Nick]‘s method of fabricating custom EL displays uses an exposed copper layer on a PCB you’d pick up from OSHpark or any of the random board houses in China. The process consists of designing a display – be it a few letters, pixels, or a seven-segment arrangement. The display ‘stack’ is a layer of painted-on dialectric, a phospor, and finally a translucent conductive ink that connects the display segments to ground. It looks like an extremely easy process, and from the pictures it looks like [Nick] is making some EL displays of reasonable quality.

[Nick]‘s work was inspired by the grand poobah of homebrew electrolumiscent displays, [Jeri Ellsworth], who managed to make a similar EL pixel on a PCB. [Nick]‘s display looks great, though, and with a little work some custom segment displays should be very possible.

High Voltage Hacks: All About Electroluminescence

Although many might not know it, electroluminescent materials use high voltage, and thus qualify for our featured topic. Many may assume that these sheets work in the same way as LED lights, using low-voltage DC power.  This, however, is not the case, as they need around 100 volts of AC current to allow them to light up.

For a battery-powered solution, this means converting the battery’s DC power to AC. Adafruit has a good tutorial about working with EL wire and powering it up using a portable inverter. One should obviously be careful to properly insulate any clothing using this material as being shocked is generally not fun.

The video after the break is pretty long, but is well produced and will give you a good background of EL use. If you don’t have 30 minutes to dedicate to this, be sure to at least skip to 2:43 to see one of the coolest EL shirts we’ve seen. [Read more...]

Jeri makes flexible EL displays

A failed chemistry experiment led [Jeri Ellsworth] to discover a flexible substrate for electroluminescent displays. We’re familiar with EL displays on the back of a glass panel like you would find in an audio receiver, but after making a mesh from aluminum foil [Jeri] looked at using the porous metal to host phosphors. She starts by cleaning foil and using a vinyl sticker to resist etching portions of the aluminum. It then goes into a bath of boric acid, electrified with the foil as the anode. As the foil etches she tests the progress by shining a laser through the foil. After this the phosphors are applied to the back surface of the foil, covered in a dielectric, and topped off with a conductive ink that will carry the AC necessary to excite the phosphors. This is layering materials in reverse compared to her EL PCB experiments. See [Jeri] explain this herself in the clip after the break.

You can see above that this produces a pretty well-defined display area. It reminds us of that color changing paint display. We think it would be worth a try to build a few 7-segment displays using this method.

[Read more...]

More EL chemistry: Luminescent ink

[Jeri Ellsworth] continues her experiments with electroluminescence, this time she’s making EL ink. The ink she’s looking for is Zinc Sulfate in a solution. The process she chose is to re-dope some glow powder so that it can be excited by the field around an AC current. In her video (embedded after the break) she talks about the chemical properties she’s after by detailing a cubic lattice of zinc and sulfur atoms with an added copper atom (adding that atom is a process called doping).

The quick and dirty synopsis of the experiment starts by washing the glow powder with dish soap to acquire zinc sulfide crystals. Then she combined copper sulfate and zinc shavings from the inside of a modern penny to yield copper metal and zinc sulfate suspended in solution. That was mixed with the zinc sulfide from the glow powder washing and doped with a little more copper sulfate. The excess liquid is poured off, the test tube is capped with glass frit, and the whole thing hits the kiln to start the reaction. The result glows when excited by alternating current, but could have been improved by adding chlorine atoms into the mix.

We’re excited every time we see one of [Jeri's] new chemistry hacks. We’d love to see more so if you’ve come across interesting chemistry experiments during your Internet travels, please let us know about them. Just make sure you have some idea of what you’re doing when working with chemicals… safety first.

[Read more...]

LED suit lights up the night

When the tipline popped up with this LED suit, part two, by [Marc DeVidts] we were expecing a simple led version of the previously known EL coat.

Well we were right and wrong in the same instance. Correct in that like predictions, the outcome is stonking great. Wrong in that this suit far outpaces EL in abilities we weren’t expecting. Namely to start off, an iPhone app over WiFi dictates to some 200 Arduino multiplexed RGB LED modules to dance randomly or follow patterns; an accelerometer and microphone are also implanted to further some effects. And finally if the suit isn’t enough to make you giddy, his PCB and enclosure milling surely will. Catch a video of the entire setup after the break.

[Read more...]

EL Wire: make it, connect it, power it

[Jeri's] back with a series of videos that outlines the step-by-step electroluminescent wire manufacturing, making EL panels from PCBs, and assembling power supplies for EL hardware. These concepts are actually quite approachable, something we don’t expect from someone who makes their own integrated circuits at home.

The concept here is that an alternating current traveling through phosphors will excite them and produce light. You need two conductors separated by a dielectric to get the job done. For wire, [Jeri] uses one strand of enameled magnet wire and one strand of bare wire. The enamel insulates them, protecting against a short circuit.

But that’s not all, she also tests using a circuit board as an EL panel. By repurposing the ground plane as one of the conductors, and using the solder mask as the dielectric she is able to paint on a phosphor product resulting in the glowing panel.

Finally, you’ve got to get juice to the circuit and that’s where her power supply video comes into the picture. We’ve embedded all three after the break. It’s possible that this is cooler than blinking LEDs and it’s fairly inexpensive to get started. The circuitry is forgiving, as long as you don’t zap yourself with that alternating current.

[Read more...]

Hackaday links: August 22, 2010

EL back-lit keyboard

A couple bucks worth of EL wire gives a nice green glow to [Mark Shasha's] T400 Elite. Hopefully [Jeri Ellsworth] has some time to pull those how-to videos together so that we can make our own EL wire to replicate this hack.

Mini kaboom

This tiny cannon is right out of Night at the Museum. It works just like its much bigger brothers would; fill with powder, insert cannon ball, and light with a fuse. Both the introduction and the follow-up videos document the destruction of various objects using the diminutive weapon. [Thanks Thorsten]

Don’t close that browser

We use Google Chrome quite a bit because it tends to be more responsive when opening massive numbers of tabs while researching featured hacks. But there’s some things we don’t like about it. Lack of built-in PDF support under Ubuntu comes to mind, but a smaller thorn in our side is that closing the last tab will also close the browser window. [Ted Schaefer] got tired of the same thing so he wrote an extension called Last Tab Standing to trap that last browser tab, opening the default window instead of closing the browser.

Amiga demo winner

This 4K demo for the Amiga AGA is the top ranked submission from Breakpoint 2010. [Osgeld] tipped us off about this and made the point that although it’s four times the size of those 1K JavaScript demos, the Amiga code doesn’t get to take advantage a pre-existing framework like Java does enjoy the benefits of running inside of a browser . Is this doing more with less?

Transformers balloon sculptures

If you’re having trouble finding that art piece to fill up your dining room you should consider building transformers out of balloons. The sculpture above is a free-standing Optimus Prime but the artist has also turned out Megatron, Grimlock, and others. [Thanks W01F]