# Custom build - backlight for transparent photo and frame - newb advice required



## hitch (Jul 6, 2013)

I'm working on a project where I plan to build a timber frame and put a photo printed onto transparent paper. I'd like to try building a low powered, not terribly bright led to put behind the transparent photo to give it some illumination against the wall. I have a few dx torches that I'm prepared to pull apart and experiment with, but I'd also like to build something completely from scratch - however I'm not too sure what to order. Given DX can sometimes take a while to ship, I'm hoping to get some advice as to what to order before ordering.

I'd ideally like to power it with as small a battery as possible - it won't be running constantly - only in the evening, and when I decide to switch it on. I don't mind if I have to swap batteries regularly. Probably 1 - 2 CR123, or a 14500.

Can anyone please suggest a driver, led combination that I should start with?

Would something like this be suitable?
http://dx.com/p/3-mode-led-driver-circuit-board-for-flashlight-dc-0-8-4-2v-106484

or would this do, with a smaller battery?
http://dx.com/p/ak-007-0-8-1-5v-3-mode-circuit-board-for-flashlights-11-9mm-50526

How about this led?
http://dx.com/p/cree-xpg-q5-3w-250lm-warm-white-light-led-emitter-w-14mm-base-silver-3-5-3-7v-222945

thanks for any help - apologies if this is a very simple question, but you've got to start somewhere.


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## Optical Inferno (Jul 9, 2013)

How large is the final piece supposed to be? The problem with using something like the XPG is that you will have a very bright spot and poor spread. Your likely going to need an optic to spread stuff out or more than one LED. You could also go with an edge lit style design as you are going to frame it.

Also, why not just plug it in? a small converter should be all you need.


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## hitch (Jul 10, 2013)

Hey, thanks for the reply! This is a bit of an experiment - the first attempt will with a picture that is about 6" x 8" - if it's successful I might go larger. I'll probably get an optic to spread the light, and was also thinking of making a bit of a filter - i.e. blacking out the optic to create a narrow slit, to try to avoid super bright spots... as I say, an experiment.

I'm not completely averse to plugging it in, however I live in a reasonably dark apartment, with windows on only one side, so I was planning to mount the frame on the wall in the dark corner and switch it on when I'm in the room to add some additional light - not expecting it to run for hours, but just to brighten things up every now and then. If mounted on the wall, I don't really want a cable snaking down to a plug from it...

I guess the main purpose here is that I've been looking at all of the components on DX.com, have seen all of the parts that are required, and have done a lot of research on other sites etc., and while I've seen lots of "first build", "my first torch", "world's brightest light", I haven't really come across a "putting all these bits together - for dummies" kind of document. I've ordered a bunch of parts anyway, and will have a play when they get here and see how I go.

Thanks again.


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## Optical Inferno (Jul 11, 2013)

Good Luck then... remember to document this or at least show us here how you did it. Ledil has an optic that is designed for back-lighting EXIT signs that may work well for you; and it works with the XP-G. Have fun.


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## SemiMan (Jul 14, 2013)

Buy a backlight unit or use a side emitter optic in a light box. That is the best way to get smooth distribution.

Semiman

Sent from my Nexus 4 using Tapatalk 4 Beta


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