I've been thinking about what a good alternative to the LED backlights would be since the screen I used is no longer made. During my last run someone suggested using an EL sheet. I've finally had a chance to order some parts to play around with and I wanted to share my results.
Here's the setup - it's a 9V battery that goes to the inverter. The EL sheet I got was not a match for the inverters output clip, but it was easy enough to solder in some wire and attach a pair of alligator clips for easy testing. Installed in a Pip-Boy I would just solder the wires directly to the EL sheet, though. In this pic the EL sheet is illuminated, though that it hard to tell with the flash. The off-state color is pink.
Here's what it looks like in a dark room with the screen print on top of it and a 1 second shutter delay:
That works pretty well, but since the EL sheet glows blueish white, it's not quite the right color. So I decided to try it with a piece of my green lighting gel:
and with the screen print:
Success! The only problem is that I'm not thrilled with the light output from the EL sheet. It is just not as bright as the LEDs. It looks OK in the photos, but I think a lot of that is due to the long shutter speed I used. In a totally dark room, you can definitely tell that it's illuminated but I wouldn't call it
very bright. Here's another look with a shorter shutter:
Here's a pro and con breakdown.
Pros:
1)
Vastly easier than building your own LED backlight using LEDs and a piece of plexi-glass (my original alternative to my LED backlight)
2) Even lighting across the entire screen - no LED bright spots
3) Easier to incorporate into a lights & sounds option: 1 9V for the EL sheet, another for the sound amp. From either of those it would be easy to also sequence in the yellow LED at the bottom.
4) The EL sheet can be trimmed to fit the inside of the Pip-Boy easily using a pair of scissors making it really easy to install.
5) Potentially easier to fit into the Pip-Boy without taking up as much space. The sheet is much thinner than the plexi, but the inverter does take up some space. The inverter is the smallest I could find and is still fairly sizable when compared with the total space available for electronics; however there are a lot fewer wires and potential loose connections than soldering a bunch of LEDs together, so it's mostly a toss up. I *think* the inverter case could be removed to free up some room, but I've been hesitant to try that at the risk of breaking it.
Cons:
1) Luminosity. It's not as bright as I'd hoped, but that could be due to my using a 7.2V rechargeable and not a full 9V.
2) Cost. The sheet and the inverter are a good 4x more expensive than the plexi and the 4 LEDs to build your own backlight.
In my opinion, the EL sheet is the better option. It still lights up, and is easier and better in a lot of respects. It is a LOT less time consuming in the scope of the overall build, and for that reason I think it's worth it.