Another DIY poster/marquee light-box - Page 11

So I finished my second poster frame over the weekend and I have some not-so-great news. You'll remember from the pics above that I received black LED lights rather than the white I ordered, and they worked fine for my first frame. I initially ordered 6 strips of lights, thinking that i would use 3 in each poster box. Then I decided to go with 4 strips per box, so needed to order 2 more strips. Well this time the correct white strips arrived, and while the black strips are fine together, they don't play nice when mixed with the white.

Here is a pic of both frames. The one on the left is the new one and the white strips are on the outisde, with the two black strips in the middle. You can see the difference in illumination pretty clearly - around the "a" in break-up and just to the left of Jenifer Aniston's shoulder.





I will take a few more pics without a poster in the frame tonight to better illustrate the difference, but you definitely cannot mix the black and white strips within one frame. I'm ordering 2 more white strips...argh...

Here's an additional pic showing the problem that's created by using white and black strip lights together...




New lights on the way...

I did that a while back with some Chinese manufacturers/sellers. While the edge lit panels themselves were very affordable compared to getting them here (as low as $35 each if bought in bulk, and that is for the 27x40 size), it was the s/h that kills it. They send it via EMS (because they want tracking/sig conformation) which adds $80-$100+ per panel (that's if you are buying multiply panels). If I wanted only one panel, the s/h was in the $180+ range. It was the same story no mater what company I emailed for prices. Some were willing to do orders of only one piece, while others had a min order of 5/10/20 or more. I soon realized that it was not worth it simply because of the high s/h costs. And, if a panel or two showed up damaged, I would have to send it back to them on my own dime for warranty coverage.

I did get some helpful info from one company though. They told me that most edge lit panels made in China are only lit on 2 sides (the long sides) with 120 led/meter strips (unless the customer wanted all 4 sides lit). They didn't tell me which leds they used though (5050's or 3528's), but after doing some research, the only ones I could find that were affordable and came in 120/meter were the 3528's. That's partly why I decided to go with the 5050's for my frame. The 50's were brighter than the 28's, and I'd be able to use less of them to get the same amount of light output. The only thing I'm trying to find now is a local place that sells affordable 8mm thick plexi or lexan that I can scribe/etch to make a light guide out of.

Here's a test fitting of the 5050's sitting in the C channel. (the "light guide" will eventually be stilling in the channel up against the leds)



When it's finally finished I will have used less than one roll (3.4 meters.... all 4 sides), and the whole frame will be 1.5" deep (more or less).


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I have an idea.... as a test get some white electrical tape and cover the black spaces between each led. Does the light output look more uniform to the other white strip leds? If yes, just find some white paint to help cover up the black parts between each led.
Edited by Sindy Ahh - 1/7/13 at 9:53pm

After enjoying a functional HT room with a plain back wall and entrance way for 5 yrs, always meaning to get around to dressing it up "soon", I'm finally making efforts to git 'er done. As part of the improvements, I'm planning on trying to build light boxes based on this thread. I've already bought 3 Spotlight frames, have them hung temporarily without light boxes, and love them.

I bought 12 spools of the lights from the same ebay seller (3528 5M rolls with 300 LEDs) intending to build 3 frames. They just arrived after 10 days in transit from China and I tested the amperage on one spool. At room temperature start up, they were pulling 1.32 amps. It would go up about 1/100 every few seconds as the strip warmed up until leveling off at 1.43 amps. This seems to fit reasonable well with the stated specs of them being 2 amps, both of which makes me question the "a bit less than .5 amp" report. Is it possible it should have been "a bit less than 1.5 amp" and the "1" somehow got truncated? If so it would match up perfectly with my test. It just seems highly unlikely to me that the the actual current draw would be less than 25% of stated specs, and that 2 rolls of the same product from the same supplier would vary so much. Something's just not adding up.

Another thing that makes me question the accuracy of the 0.5 amp report is the later report of the hot power supply when connected to 4 strips. If the strips are running nearly 1.5 amps each, he had almost a 6 amp load on a 5 amp PS, which could explain it getting so hot. I didn't see any follow up on the problem by the OP of the problem. Was the actual problem ever determined to be something other than excessive load?

As I've thought more about the project, I think I am going to buy and use 5M strips with 150 LEDs instead of these with 300 LEDs per 5M, and use up to 6 strips (5 might be enough?). This would give me 900 LEDs total, and I'm hoping the 6 strips of 150 per 5M will pull the same amps as 3 strips of the 300 per 5M (the specs indicate it should). I think this will allow for a much more uniform, grid like spacing of the individual LEDs, instead of having LEDs more vertically concentrated with wider horizontal spacing. I think this will achieve a similar but more uniform brightness with 25% less LEDs compared to using 4 strips of the 300 per 5M style. If anyone is interested in the 300 LED style please DM me as I am going to resell mine due to switching to the 150 LED style.

A financial downside is the 150 style is roughly same price per 5M roll as the 300 style, and it takes more 5M rolls of the 150 style. But on the other hand, it looks like the 5A PS can only handle 3 rolls of the 300 style, meaning either the the spacing between strips in the frame will be wider than desired, or one must buy a bigger or 2nd PS to run 4 rolls of the 300 style which would cost more. So there is some offset in comparing costs. But to me, even if I spend an extra ~$20 on LED strips I consider it reasonable if it leads to more uniform lighting, fewer total LEDs (less heat and smaller PS requirements), and the total project cost will still be well under a commercial built light box.

Here's one seller of 3528 5M rolls with 150 LEDs per roll as an example: 3528 5M rolls with 150 LEDs. I haven't had time to extensively shop and compare yet, so I'm not sure that I'll buy from this seller.

A question for cuzed2 if you are still around... what did you cover the sides with to hide the MDF? In the picture showing the switch, you can clearly see the contrast of the seam between the nice looking outer trim and the MDF behind it that doesn't look as good. On the picture of the finished product, the side view looks great and uniform all the way from front to back. Did you cover the sides with a laminate, or do something else to cover the MDF? I also want to thank you for sharing your work and allowing others to copy your ideas, and thanks to the other contributors as well.
Edited by wadew59 - 2/5/13 at 9:35am

Any ideas on how to hide the power supply INSIDE the frame? I built my walls with outlets up high so that I can mount the frames right over the outlets. (the outlets are on a x10 relay for switching on and off)

Should I secure it somewhere in the middle? If so, would just routing the LEDs around it be OK?
What about a corner, would that create a dark spot in that corner?

As others have posted in the past, I wouldn't recommend having the PS inside because of the heat, especially if you have more valuable posters. I would be concerned of it creating a dark spot too. Moggie's pictures looks like he installed the PS inside, hiding it in a cavity in the outer frame part to avoid a dark spot. I'm not sure if he provided any ventilation to relieve heat build up. It's been awhile since I reviewed his posts and my memory is fuzzy, but I think he may have said he doesn't have a need to leave them on for long periods of time. I might be confusing him with someone else's post on that comment though.

Here's what I'm planning on trying: Recessed Outlet. I'm going to simply put in a blank plate in place of the A/V connections shown in the picture, and I think my PS will fit in that cavity, all hidden behind the light box.

Cuzed2: I looked at Moggie's build (dang, I wish I had his woodworking skill on making the frame detail... sweet!), and he has 15 strips. The inside horizontal measurement of the Spotlight frame (the amount of visible poster) is just over 26.25 inches, so that's an avg of 1.75" per strip. On the 300 LED strips, each LED is roughly 5/8" apart, so there is an extreme difference in the vertical & horizontal spacing of individual LEDs, being almost a 3:1 ratio. Although the product states the LEDs have a 120 degree viewing angle (which is only 60 either side of a perpendicular view), it seems obvious the LEDs quickly become less intense as the angle increases from a straight on view, which is a critical factor to overcome in trying to keep the light boxes shallow but yet evenly lit. So my theory in trying the 150 LED strips is that I think I can achieve the same over all brightness with better uniformity and with fewer total LEDs simply by more uniform spacing of individual LEDS. I also think I may stagger my LED strips so that LEDs on one strip are not horizontally in line with the LEDs on the adjacent strips. I'll play with it as I start my build and do some comparisons. I really doubt it will make much difference to the avg naked eye, but hopefully it will satisfy my OCD.

The Chinese lunar New Year Celebration has begun, so I don't think I can get any of the 150 LED strips shipped until the 17th, and then 10 days or so in transit, so it will be awhile before I can experiment and compare.

I'm not so concerned about heat as I could always oversize the PS to say 8A and not worry about overdriving it. I am worried about dark spots due to spacing and did see where Moggie hid his PS, but I don't have the skill (or time) to make something so extravagant. Plus, for one of the posters I'm making, I bought a 4-way controller to try to do some chasing effects too and will need to hide the controller somewhere inside as well. With that said, I think I'll probably forego the LEDs and stick with florescents. I found some lampholders that are only 1.7" tall, so I should be able to build a frame that's 2.5-3" tall to keep to a somewhat low-profile design.

For those with the WIDE frames, how much gap is there between the mounting screws and the edge of the outside of the frame? I'm rethinking the LED route and wondering if a power adapter could be hidden behind the snap frame, but outside of the "box".

Just eyeballing here but I think the distance is about 2" from the mounting screw to the outside of the frame.

I'd say more like 1.5". Look at my pic from response #9 of this thread. I used 1x2" pine for the box and that is shower backing board behind it which is 3/16-1/4". That should give perspective.

I doubt you could fit a box back there and have it completely hidden. Just do what most of us are doing and use a recessed power box behind the poster.

I've already got outlets in the wall behind where the posters will go, and I'm not about to rip those out as they're putty'd and green glued in. I guess I'll have to just order a frame and see what I can work with.

Why not do something like this for an edge lit led light box.
http://www.youtube.com/watch?v=VYSVJMu5ZDQ

looks pretty simple for most DIYers

Troll?

I found it helpful and it has me rethinking the possibility of edge lighting. I had considered Sindy Ahh's approach but thought it probably needed a little more tweaking to materials better suited for this particular application. Sindy stated "The overall light output from the acrylic sheet is not as bright as that of the back lighting method shown in this thread..." which gave me some concern, and also if I bother to go edge lit, I'd like to get the depth down a little more than Sindy's build. The video link post above led me to http://www.lucitelux.com/Lucite-Lux-Product?productID=10 which I think has possibilities as it apparently was developed specifically for edge lighting applications, and it's available less than 1/4" thick. I'm going to investigate further on availability and pricing to see if it might be worthwhile.

If I go the edge lit route, I'm thinking I'll use cheap aluminum channels from Lowes or HD and eBay LEDs instead of the similar products from the youtube video source.

I had hoped to be further along or even already had some boxes built, but there never seems to be enough hours in a day. Now there's more options to explore first, so I'm not sure I'll ever have light boxes.

For anyone who's still hanging around this thread (and surely knows more about electricity than me! ) can anyone tell me if I need to be worried about voltage drop in the scenario cuzed describes above?

I am running 4 strips of lights on the PS and it does get a bit warm. Rather than using a recessed box to put the PS into the wall, I plan to use a run of 12 or 14 gauge romex through the wall to an equipment room where I can mount the PS out of sight. If I add about 15' to 20' of romex between the PS and the first LED lights, am I going to have voltage drop? Will this increase the load on the PS?

Thanks all!!
(Slightly embarrassed by my lack of electrical knowledge here... )

There will always be a voltage drop, simply because there is some resistance in the wire. But that is thoeretical. You are going to be drawing 5 A on wire that is rated for 15A (14 ga) or 20A (12 ga).

14 Ga has a resistance of around 0.0025 ohms/ft
12 Ga is 0.0015 ohms/ft

So, for a 20' run, you are talking .0025*20*2 = or 0.1 ohm. BTW, the last times 2 was because you need to figure in the return resistance as well.

Now apply ohms law E=I*R 5A*0.1 OHM = 0.5V drop

For 20 Ga .0015*40*5= 0.3V drop.

Not enought to worry about in either case.

Excellent - thanks for the informative and easy to understand response jayn_j! My electrician is coming to run the wires for me tomorrow. I will report back soon.

Did you leave a gap between the trim and the snap-frame so it would have room to open? I debating between butting up the trim directly to the side like you did, or tucking it under the "lip" in the snap-frame. If I butt it up, it looks like I might need a 1/8" or 1/4" gap, yes?

Yep - depending upon your trim profile, you will need a gap to give the frame enough space to open.

Ok time to revisit this thread as i need a little assistance.

I built about 8 of these frames and for the most part I am very happy with how they turned out. I do have an issue and am looking for some alternative ideas.

Each frame has 4 strips of LEDs inside the frame. These were initially wired with 2 strips end to end and another set with 2 strips end to end. Power wiring was wired where the 2 double strips met together so that the power was basically in the middle of the strips. This kept the light output nice and even and made the frames look very good.

Problem:

Using 12v 5A power supplies ONE PS ran way too hot to power all the LEDs so I had to redo each frame with 2 PSes per frame - I still haven't finished them as I have been busy (and lazy).

Here is my question. Is there any other way to supply power to these strips easier, preferably with 1 PS per frame. The reason I ask is I want to plug all 8 frames into 1 power strip that I can then turn on and off via a remote. I can solve the on and off with a remote issue np but I really need to not have 16 power supplies in total plugged into 1 power strip/1 outlet.

Any thoughts?

Greg

You could try to find a PS rated for 8a or even 10a. That theoretically should keep the heat down.

Well I'm ok with 1 PS per frame to be honest - 2 is just a bit much.

As I recall I tried a bigger PS when I first built them to avoid having to redo each frame for 2 PSes and it got just as hot as the smaller units.

I'll look around some more and see what I can find. I just don't want to redo the lighting inside as it was a fair bit of work and to be honest I am actually pretty darn happy with the results.

Greg

Electricity isn't magic. It follows a strict set of rules.

What is 'magic' is that you all are purchasing random power supplies from random vendors and using them to power varying numbers of strips from different vendors. You need solid numbers.

The only way you are going to know for sure is to take some measurements. Head over to Radio Shack and buy a multimeter that is good to at least 10 Amps. It will cost you around $30-40 and is useful for all sorts of projects.
Break the positive line heading into the lightbox and place the multimeter in series, making sure that DC AMPS are selected, and that it is either autoranging, or the 10A range is selected.
Turn on the lightbox and see what the current draw is. Compare this with the power supply you have selected. In order to keep them running cool and to have some degree of reliability, I would suggest that the power supply be rated at least 50% higher (double is better) than the shown current draw. For example, if the current draw is 5A, I would select a 7.5A or even a 10A power supply.

These cheap chinese power warts tend to be over-rated. If the unit can stand a 10A draw for 10 minutes without frying, they will rate it at 10A. This is why it is best to add some headroom.

Well the larger PS seems to have solved the issue. I got a 10A supply and had it plugged for a good 6+ hours yesterday and it was barely even warm so I think my issue is solved.

2 done - 5 more to go, one of them being a "special" project which I'll post once it's finished (parts are on backorder).



I used fluorescents instead of LEDs because I had ballasts and bulbs from some old fixtures and I had used them in the past with good results. I forgot to take pictures of the insides before putting the posters in so I'll grab some shots when I get the next set finished.