Questions about Light Sheet

[mtmeredith]

Hello,

I have read articles that mention using "light sheet" to light up nacelles etc. What is this stuff and how do you apply voltage to it?

Thanks

[DaveVan]

I have a 8x8 inch sheet of the stuff. It has two metal connectors attached to the edge. When power is applied it lights. But be careful as the edges can shock you pretty good! It is cut with an x-acto ot scissors etc. Mine came from a model RR supply co.

[Paulbo]

Here's where I've been buying mine lately - it has a little more info about connecting to it.

As for providing power, you need an inverter that pumps up the voltage pretty high - as DaveVan says, it'll give you a wicked shock.

For most nacelles you'll want strip material like this: http://adafruit.com/products/416

[merkin63]

I got an experiment kit but was not overly thrilled.I got a sheet of white EL film and it is just not that bright unless in lower light settings.I know people that swear by it but it won't last anywhere as long as l.e.d.s. and this is what they use in those timex indiglo watches which dim over time.Also if you live in a very humid climate like I do the EL film will dim faster.I still use it for certain projects but add a desiccant silica pack from some electronics I have bought and hide this inside the build before closing it up as this soaks up the humidity and will give you longer life of the EL film.This stuff worked a lot better when I lived out West in the US where the climate is dry:~D

[ModelMan]

I've used light sheet in a couple models over the years and it is the only option for very specific conditions, such as needing a near-paper thin light source.

EL Sheet, wire and ribbon all suffer from the same problems.

1. The high voltage inverter is just as likely to burn out as not, is very bulky and for smaller models needs to go into base of some sort and on bigger models it's just a big block occupying space and throwing your model's weight off balance if you don't take that into consideration.

2. Lifetime. All EL products dim by half their output in very little time, tens to hundreds of hours compared to tens of thousands of hours for LED's. And EL is simply not as bright as other light sources.

Advantages, you can cut it to shape, you can roll it in a tube and as mentioned it is nearly paper thin so can go where no LED can trod.


There are two other options for nacelles.
1. CCFL tubes. These can be finicky, do require a power inverter like EL products, and if you need to remove the outer plastic tube to fit inside a model, the inner glass is highly fragile and shatters into very sharp small shards -and you will get major shock if you touch the live wire that runs from end to end.

2. LEDTape. A paper-thin ribbon about 8mm wide that has pre-resistored SMD LED's on it. About 3mm tall with an adhesive backing, it can rolled, twisted and formed into almost any shape and can be cut from one inch (every third LED) to yards and yards, using ~20mA per 3 LED segment. Like EL and CCFL, LEDTape runs on 12v DC, but unlike those other two, LEDTape has normal LED's so they don't need a power inverter or any special requirements of any kind.

Research on LEDTape is required though. Commonly you'll find the 3 LED's per two inch variety which goes from $5 or $6 to as high as $24 per 30cm. This 'single-density' ledtape makes for huge hotspots in nacelles, you may as well use normal LED's.

If I may, Modeler's Brand Double-Density LEDTape has 3 LED's per one inch and comes in Regular and Smooth versions. The Smooth version is coated with a clear epoxy which spreads the light along the length of the tape, making an even, smoother light and is great for nacelles.

Here's a comparison picture.
http://www.modelersbrand.com/misc/ledta ... re_v01.jpg

Top to bottom, Modeler's Brand Ultra-Smooth, Smooth, Regular and then the 3LED's per 2inch strip on the bottom you can find elsewhere.

Wherever your research leads you, happy modeling!
Best,
Tom
www.modelersbrand.com