EL Lighting

[Westozy]

Hi all,

Is there anyone out there who can shed some light on the mysteries of EL lighting? I'm sure a detailed description or a tutorial would be appreciated by many, especially me!

Regards, Gwyn

[Michael Carter]

The briefest of explanation for how it works can be found here:
http://en.wikipedia.org/wiki/Electroluminescence

The other sites I found on EL lighting only wanted to sell it to you, not tell you how it works. I guess they assume you already know.

One thing that puzzles me is that in the F-4E POH, there is a caution about having the EL panels turned on during ground or daylight operations. EL is supposed to run cool and does not emit any sort of harmful radiation. I haven't been able to find out the 'why' about this caution.

There were three strips of this stuff on each side of the Phantom II.

[Bob Reed]

I do know where there is one but.. I don't think I can lay my hands on it right now. The guy that wrote it is out of the country and I looked online and it is no where to be found. I do know there are a couple of down sides to it.. Number 1 is cost. Number 2 is the high voltage it takes to run it and number 3 is the fact that if conducts electricity so every switch, button rotary and annunciator must be shielded from it or zap.. You get rapped.....

[Mike.Powell]

I once read a technical article explaining the physics of EL. The details didn't stick. However, from a more practical standpoint, EL is light emitted by some materials when exposed to moderately strong, changing electric fields. EL panels are generally made by sandwiching such a material between a metallic foil and some sort of moderately transparent, conductive layer.

An EL panel is powered by an AC voltage connected to the foil and the transparent layer. The voltage is typically between 80 and 200 volts with a frequency between 50 and 2,000 Hz. You can buy small inverters that will supply this voltage. However, there is nothing magical about them. With care, any suitable AC source can be used. The biggest issue is safety. EL panels can be dimmed by varying the applied voltage.

EL panel material is available both as small finished shapes (light night lights, small sheets, etc.) and as bulk rolls. EL material can be cut to shape, though care should be taken to seal the edges. Cut edges both expose the electrical connections and allow moisture access to the EL material. Once the EL material hydrates it no longer luminesces. This was a problem with older EL panels; newer panels may have fixed this.

There is a list of EL panel sources on my links page http://www.mikesflightdeck.com/links_1.htm about a third of the way down. Look for the heading "Electro-luminescent Panels".

[pylet]

Hi,

What a pain in the rear this El Sheet thing is. I was trying to back light my MCP. I wasted almost a complete sheet due to no instructions with the order. I couldn't get the sticky backed tape to light up the sheets so I tried soldering wires directly to the sheets and even at the lowest setting of my soldering iron it melted the sheets. So don't do that. I finally got a document of instructions from the company. There is a fine white line between the two bus bars and if any part of the copper tape is touching that white line it won't work. That was my 1st problem.

Next I tried to keep the bus bars on the outer edge of the panel and with the sheet having an 1/4" of area on the outer edge that doesn't light up, I tried folding over that part so that I got the whole panel to light up. Well come to find out you can't fold the sheets because it breaks the internal membrane thereby making it completely useless.

So I grabbed my second sheet and this time placed the bus bars near the middle of the MCP. I used two separate pieces because it's to thin of an area between the three vertical buttons in the middle of the panel. By placing the bus bars near these three buttons I was able to get complete coverage and keep the sheet flat. I then used a silicon glue and glued the sheets in place because if it didn't work this time I'm not trying it again. Those sheets are expensive. All I had left to do was solder wires to the tape, then stick the tape to the bus bars and put the panel back together.

I bought the apricot colored thin plastic like others reccomended to make the yellowish glow but it really reduced the light output so I left that off. I won't need to install a rehostat to reduce the brightness because they barely shine though as it is now.

I took a couple of pictures of the cut out sheets and placement in the MCP panel. I have had a hard time finding basic information on these El Sheets. I was hoping that others would have done this before me thereby saving me money and time. So hopefully I can help others that go this route.

I have uploaded all the files and pictures that I have on my EL experience.

C-ya and good luck,
Lyle

[HansJansen]

Hi,

Somwhere else (don't remember the exact place however) I read about an EL WIRE which you could lay over your backplate like a snake... Anybody ever saw/tried/used that?

Hans

[Mike.Powell]

EL wire is sold by Being Seen Technologies (www.beingseen.com (http://www.beingseen.com)). It doesn't put out nearly as much light as EL sheets do. A few years ago someone posted on avsim (?) about trying, unsuccessfully, to use it for panel illumination. I don't recall the details. Perhaps a more careful positioning of the wire would result in a workable solution.

[Westozy]

Thanks guys for the great replies...

Gwyn

[alaxus]

EL wire is crap, I have tried it and it doesnt put out enough light.
Atm I am looking into this stuff, its el tape 1/4 in wide.
http://www.e-lite.com/index.htm

One of the reasons I like the tape is that you dont have to poke holes in it. And you can just fold it over around corners. Seems to be pretty cheap to. @ $15.00 AUD per mtr.

I am going to order some to try out.
I will post back the results.

Westozy, the mob in aussie land thats sells it is in west australia.
http://www.sunindustries.com.au/flatlite.asp

[Westozy]

Thanks Alaxus, great stuff!

Gwyn

[mauriceb]

Of course you could avoid any backlighting issues by using panels with integrated backlighting such as the IBL panels produced by FDS. The extra cost for these panels is well justified in my opinion when you consider the extra cost & grief associated with EL sheets.
But that's just my opinion and I don't work or have any business association with FDS (I'm just a happy customer :)

Maurice

[alaxus]

Of course you could avoid any backlighting issues by using panels with integrated backlighting such as the IBL panels produced by FDS. The extra cost for these panels is well justified in my opinion when you consider the extra cost & grief associated with EL sheets.
But that's just my opinion and I don't work or have any business association with FDS (I'm just a happy customer :)

Maurice

That of course would be nice if FDS made panels for my said Aircraft.

[mauriceb]

That of course would be nice if FDS made panels for my said Aircraft.

That is indeed a problem, although new panels are in the works. That is also why I picked a 737 since I wanted fast progress and a 737 seemed like the best choice to me since parts are plentiful.

But anyway, my only point really was to consider all available options and to weigh the pros & cons of the different methods of back-lighting. Sometimes the hidden costs & problems are way more than you anticipate and paying a bit more at the beginning can be the cheapest option at the end (assuming you have a choice of course).

Maurice

[Michael Carter]

In some ways I'm fortunate that the 727 was retired by most US domestic airlines. Parts are plentiful for the most part, and relatively cheap as far as real aircraft parts go. :grin:

The average control head or module sells for $25 to $100 and it includes the whole thing. Knobs, lights, switches, Dzus fasteners, and the important factory backlit panel.

I don't know what an aftermarket backlit panel costs, but by the time you add the required switches and/or indicators the cost surely climbs up into the real used aircraft part range.

[Electroluminescent]

Hello,

I have a lot of experience with electroluminescent lighting and I would be glad to answer any of the questions that come about.

A short explanation:

El works on AC power at either a high frequency, high voltage or both. The AC current excites the electrons in the light emitting phosphor and this action creates the light.

El can work from just about any power source including batteries, you just need the right inverter to convert the source power to the AC power that the lighting needs.

Generally, if you are going to use batteries, it is good idea to deal with commercially available types like AA, AAA, C, D and 9V.

The best batteries for their size and power output is the AA. They are also very inexpensive if you buy a no name brand. In my experience, the energizer and duracells are only 3-6% better than the no-name ones and they are less than half the cost.

Direct your questions here and I would be glad to help out in anyway I can.

thanks

Ed