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By Beachrunnerjoe
#177980
I bought a wall poster, printed on 100# paper, and framed it. It looks great in the living room and I thought it would look even better if I could figure out a way to accentuate the light sources in the picture by back-lighting specific parts of the image. Here's my conceptual approach...

1. Trace the areas of the image (the light sources) that I want light to shine through
2. Scan the trace into my computer and create an Adobe Illustrator file that can be read by a laser cutting machine
3. Use a laser cutter to cut the trace lines on sheet of sheet metal
4. Place that sheet metal behind the poster in the picture frame
5. Lay twelve strands of 15mm light tape behind the sheet metal and wire them up to a power source (either battery pack or a plug)

The reason I want to use sheet metal and a laser cutter, rather than doing it by hand with tinfoil and a razor, is there are some cutouts that are very close to each other that will likely tear if I do it by hand. Also, a laser cutter provides better definition.

The area that needs to be lit is roughly 36" x 12", which would require about 20 strands of 1m x 15mm light tape. My questions are...

1. How can I wire that many strands of EL tape to a single power source?
2. Would you suggest using a different product than the 1m x 15mm light tape to cover that amount of surface area?

I'm still doing my own research on the questions I posted above, but I thought I'd post this question in the meantime. Thanks in advance for your wisdom!
By Mee_n_Mac
#177987
EL tape is fairly dim. How sure are you that it'll work through the paper ?

The datasheet says the tape consumes 3.6 mw/cm^2 @ 400 Hz. If you use a 2787 cm^2 panel, that means the inverter must supply 774 mW. SFE says their big inverter can drive 10-15 m of EL wire. Each of their 3m wires dissipates 216 mW @ 400 Hz. If the big inverter really can drive 5 of them, that's ~ 1W and should be enough (> 0.77 W) ... but ...

The inverter's datasheet says it runs at 2000 Hz. EL consumes power proportional to it's driving frequency. EL wire consumes ~1 W/m @ 2000 Hz (per the datasheet), ~ 5x the 400 Hz number. I'll assume EL tape follows suit. So you need a 3.8 W inverter. SFE says (the inverter's datasheet is confusing re: point) that their big inverter outputs 5W (nominal) @ 2000 Hz ... so it looks like 1 inverter can drive your backlight.

Connect your strips in parallel.

https://www.sparkfun.com/datasheets/Com ... 20wire.pdf
http://dlnmh9ip6v2uc.cloudfront.net/dat ... cation.pdf
https://www.sparkfun.com/products/10469
https://www.sparkfun.com/datasheets/Com ... V12M-1.pdf