LED flexible lighting strips to illumnate a layout?

[videobruce]

Though I'm surely not the first to think about this, I though a thread on the subject would be worth while.

I needed lighting under my layout for wiring and I got tired of using a florescent trouble light to do the job. I thought about fluorescent tubes, but ruled those out as did with CCFL's due to size, heat, and the number that would be needed for even lighting. The only other choice is LED's, but the typical enclosure or the LED "bulb" gets me back to the above (without the heat issue). Then there is the cost.

One point I want to make;
I ruled out Xmas tree light strings and those awful looking "rope lights". I spent too much time and money on my layout to degrade it by going cheap.

Some preliminary details are needed. The most common SMD's (Surface Mount Device) used for these strips are the 3528 and the 5050. A comparison between the two is here;
http://www.ledlightsworld.com/page.html?id=32
http://www.flexfireleds.com/pages/Comparison-between-3528-LEDs-and-5050-LEDs.html

The issue of color temperature is here which is a huge issue with LED's;
http://www.digikey.com/us/en/techzone/lighting/resources/articles/understanding-the-color-white.html

There is also light output in lumen's which is not always listed. Something I consider the most important spec other than temperature;
http://www.colorkinetics.com/support/whitepapers/Evaluating_Light_Output.pdf

To make matters worse, there is a issue of "binning" due to the inconsistancy of mass production of LED's;
http://www.digikey.com/us/en/techzone/lighting/resources/articles/decoding-led-bin-labels.html

Now, if I haven't scared you away or confused the hell out of you, read on.
I knew of these "strips", but never looked into them. Doing some preliminary searches brought me to everyones favorite eBay. Searching there brings up dozens of sellers, mostly from Hong Kong that I didn't want to deal with. Checking "US only" removes most of those, but still leaves some since they are now just stating they ship to the US to get around the "US only".
Try this search. It reduces the count down to 530 sellers;
http://www.ebay.com/sch/String-Ligh...led+flexible+LED+lighting+strips&LH_PrefLoc=1

For those of you that don't like eBay, here is a link for a Amazon search (fine tuning may be necessary);
Amazon.com: led flexible strip lighting

All of the above are also available in aluminum housings, but at a higher cost.
If you don't want to bother, or have some other reason, there are these 'fixtures" available;
http://www.amazon.com/Bright-LED-cabinet-panels-powersupplies/dp/B003AKCT5G/ref=cm_cr_pr_pb_t

 

[videobruce]

I received my order yesterday from NJ (in spite of Sandy) and was surprised at the size (or lack of) of the reels. You can't tell from any of the photos since no reference was shown next to them. The "reel" that was used was a 8mm movie reel (if you can believe that). Something I haven't seen one in 20 or so years.
They came in static resistant pouches, though diode & resistors don't really have static issues, but nothing wrong with that.

Now the details of the specific LED's.
I choose the smaller 3528 over the 5050 since this was going under the layout, not above, only as a 'work light'. I wasn't sure if these were going to be bright enough since I didn't want the brighter "bluish' white' strings, I chose the "warm white 2700-3000k. I can always add a 2nd string if these aren't enough.
I have to say, there is no way I would remotely consider the "clear white" color, as many of these sellers call the typical bluish LED. These are blue enough. Viewing from the side produces a much warmer color. Viewing from straight on, they have a slightly bluish tint.
The plywood was painted white, so were the 'L' girder framework. Shelve depth is less than three feet. There is better reflection of light as opposed to non painted ply helping the situation.

After confirming both strings worked and they did, the 1st test was current draw since I didn't believe the specs posted. With 300 3528 LED's, the 5 meter (16') string drew ONE AMP at 12 vdc. I used an adjustable bench PS with volt & amp metering. AC current will depend of the efficiency of the PS you use. Outdated "bricks" (transformers) will be more than switching supplies. I didn't have a 2 amp switching supply available, but had a 3.3 amp which I will use giving me the ability to add another string if needed.

I also tested the dimming ability. These LED's fired around 7.5v (very dim, not really usable) and seem to achieve maximum brightness between 12 and 13vdc.

I noticed these 5 meter strings are actual comprised of a number of separate 20" sections that have ten sets of these "3 packs" that are soldered together. That was a surprise.
Measuring the temperature (after being lit for 15-20 minutes) in a ambient room temperature of 65 degrees and found these to run around 75 degrees. Just warm.


Attached are photos of:
solder joints,
single '3 pack' closeup,
the shipping reel next to a $5 bill for size comparison

 

[videobruce]

Here are pics of the strips temporary mounted to the 'L' girders under the layout. These have adhesive on the back that actually might hold for the long term, but I will probably apply clear (or white) acrylic caulk as a additional measure.
I needed around 27', so I either cut one of these or overlap where they meet in the middle, starting the ends of each strip from the ends of the table. I believe the actual length of the strips are more than 16", but haven't measured yet.
One strip is decent, not bright, but workable. With both strips in use, output is more than enough telling me a 5050 strip as opposed to this 3528 would of been the better choice.

If you focus on the top of each pic, the single strip really isn't that bad, ignoring the carpeted wall that sucks up light, making it look much darker. Finally, the "warm white" is very pleasing. I wouldn't want the common so called "clear or true white".

Though, I surely didn't need "waterproof", I find this encapsulated strip a huge advantage over a bare flexible circuit board with LED's & resistors exposed to getting hit and damaged. I'm not sure about mounting as I'm concerned if either strip fails and needs replacement for whatever reason. I was planning on applying acrylic caulk to supplement the adhesive strip, but I'm not sure now. using pieces of 24 gauge wire does hold these in place, but needs refinement.

 

[John P]

I'm skeptical that those strip lights will ever be bright enough, in the quantity that a modeler can afford. At our club I've been playing with 1 Watt LEDs set up in groups of 4. All the light in this picture comes from one set:

http://tmrc.mit.edu/progress/reports/2012/04/IMG_1811.JPG

 

[CaptSuperCow]

I do not have experience in model track lighting, but I do have experience in whole house lighting, projection lighting and undercabinet lighting. We specify a large number of LED strip lights for UC lighting and I believe that what you're attempting to do is very similar.

After reviewing your photos, unless they have been altered by your camera in any way, are not 2700K lights. Almost everything we specify is 2700K; cheap LED manufacturers are really bad about consistency in their diodes. I would recommend using ElementalLED strip lighting at a minimum of 2.16watts per foot, preferably with a diffuser.

Elemental's pricing is very reasonable, especially if you look into the kits; which come with a driver, dimmer and the attaching cables. We've used these in a number of kitchens now and they don't add un-necessary heat and look great!

Here is the strip I'd recommend for you:
http://www.elementalled.com/brighter-led-strip.html

 

[fcwilt]

http://www.superbrightleds.com/cat/led-strips-and-bars/

Here is another source.

 

[John P]

2 Watts a foot sounds about right based on my experience; my rig had 4 1W LEDs and I think if you repeated that assembly every 2 feet, you'd get a nice result. I'm not sure about color temperature; they claimed to be "warm white". I used the "Star LED" style like this:
http://www.futurlec.com/Star_LED.shtml

With those strip LEDs, is 13 bucks a linear foot a price many people will be willing to pay? I found the LEDs on eBay direct from a Chinese supplier and they were 60 cents each delivered, but then they have to be mounted to a heat sink and fitted with a driver. However you do it, the combination of cost and hassle is significant.

 

[t44florida]

LED strip lights

I used LED strip lights as an overhead light to illuminate a layout/diorama. It does a nice job. The layout is about 6 feet long and I used two 5 foot strips. The LED's are super-brights. I will post video here. The main focus of the video is measuring amps; but the amps drawn (2 x 5 foot strips) is shown and the light output is seen at the end. Not sure of the size area you intend to illuminate and to what brightness. Maybe this will give you some idea. Aj
[YOUTUBE]?v=s55fT0N5fPg&feature=plcp[/YOUTUBE]

 

[diburning]

If you get any heat, it's produced by the resistors and not the LEDs.

As for color temperature, that can be fixed. Get some Tamiya paint. Tamiya clear yellow or clear orange will get you some pleasing color temperatures without blocking the light and remove that annoying blue tint. Just dab a little onto each LED (dry brush it if you can to add a thin layer)

 

[videobruce]

After studying the links I provided in the OP, the issues of bins & binning through quality control, the maxing of the yields of these LED's, also the fact these so called warm white LED's are not necessary that "warm" in actual appearance and lastly the limited, narrow visual spectrum brings up questions. When it comes to reproducing colors on your layout, assuming you will use these for above lighting (unlike my use), I would suggest trying at least two RGB strips with a warm white strip in between to 'fill in' the void of a single color LED.

Of course this is a suggestion I'm thinking about trying. Adding the three primary colors together produces white. Separate red, blue & green LED's are very vivid by themselves. It would then reason the resulting combined output would be a better white.
There is at least one "controller" for these combo RGB strips that allows output & color control that appears to have possibilities for changing the 'mood' of the lighting. Dawn, dusk, etc might easily be achieved going this route.

Just to show how "nutso" one can go with RGB strips, they have individually addressable LED strips available, where each LED cluster can be changed from it's neighbor;
http://www.pololu.com/catalog/product/2540

 

[videobruce]

CaptSuperCow & fcwilt;
Thanks for the links, but they are too pricey. While I'm sure the consistency is better, most here probably feel what I choose is too expensive let along those examples.
(Unless you use to work for Bain & Company and scammed the public out of 10's of millions and can really afford it.)

If you get any heat, it's produced by the resistors and not the LEDs.

I measured the heat by IR and by feel and it was fairly evenly distributed along the strip.

.

 

[diburning]

Interesting... LEDs shouldn't generate much heat unless they're burning up or emitting a lot of IR wavelengths (in which case, they'd be pretty horrible LEDs unless you wanted an IR LED). The LEDs should generate little heat, but the heatsinks should take care of it. Does it get hot enough to melt plastic? I'll be mounting them to the underside of a passenger car roof, so I wouldn't want it to heat up enough to warp the car.

 

[videobruce]

It's slightly warm, sure little talking about.

 

[fcwilt]

CaptSuperCow & fcwilt;
Thanks for the links, but they are too pricey. While I'm sure the consistency is better, most here probably feel what I choose is too expensive let along those examples.
.

What did you end up paying?

I was thinking that $9 a foot was a good price.

 

[videobruce]

Doing additional research, I came across these sites with information regarding lumens output & types of strips. The majority of these strips use either the 3825 or the 5050 LED SMD as already stated. Either one of those can be either a 30 LED/meter or a 60 LED/meter strip.
Adding to the mix are 120/meter & 240/meter 3825 strips.

Before I go into luminous output, go here for the different encasements available, making them waterproof and "tool" proof for exposed areas;
http://www.ledstrips8.com/wholesale/super-bright-12v-flexible-waterproof-led-lighting-strips/

First, go here and click on each type of strip and look at the lumens (lm/m) and the Efficiency (lm/W) columns to see the difference between the types of LED's used;
http://www.kingway-led.com/products/Flexible-LED-strips-14-1.html

Using the "warm white" color, lumens per meter output varies from a low of 165 lm/m to a high of 1680 lm/m which is over a 10:1 spread. The site is the manufacture, not a outlet, no prices are available. Since these companies use the same chips from one company to another, I would like to assume lumen output would be similar (other than possibly color consistency).
All the combinations have the same efficiency (66 lm/W) except the 5630! That has a efficiency of 76 lm/W! A oddity is listed with the 60 LED's/m strip of only 53 lm/W. I don't know if that is a typo or not.

But, there is an additional chip of interest for even greater output; the Samsung 5630. Though more expensive, considering the output, it is cheaper per lumen. Most of the listings for this 5630 only have it as the typical 'cool' white (bluish color).

Going in the opposite direction, there is a 335 LED. Being smaller, output is only 150-200 lm/m. If space is a concern for other applications, this could be a solution;
http://www.lya-ledlights.com/html_products/SMD335-30LEDs-led-strip-light-36.html

If that still isn't bright enough, there are 24v versions of this with another 1,000 lm/meter output;
http://www.rayen-led.com/samsung-led-strips/129-samsung-5630-led-flexible-strip.html

There is no two ways about it. I'm sold on this concept. Cost is the main issue, so shopping around is essential. Prices I have seen have ranged from $13 to a high of around $230 for a standard five meter reel. That is $1.25 to $14.40 a foot.
With the two strings I bought, both are ok so far, but that isn't long term testing. The power supply I'm going to use is a switching type with enough overhead. I have a string of 5050's 30 LED's/m ordered to compare since I will just double up the original pair of 3528's and fill in the rest of the length with this 5050 for a brighter coverage. I suppose if I didn't do the 'double up' test, I would of settled for a single string, but I figured for an additional $18 more, the 5050 string was worth it.

 

[John P]

This one is at Amazon at $12 for 16 ft (= 5 meter, that seems to be the standard length). It runs on 12V, 2Amp if you use the full length. It might not be quite bright enough, but these things are subjective.

http://www.amazon.com/HitLights-Flexible-Lighting-Strip-White/dp/B005GL5UG2/ref=pd_cp_e_3

 

[diburning]

Wait, aren't they all wired in parallel? I was thinking of cutting out a section or two, and hooking it up to 12 volts. Will that be too much?

 

[John P]

It says you can cut it every 3 LEDs. That implies that they're wired in groups of 3, with all the trios in parallel. That would make sense as the voltage drop in a white LED is about 3.6, so 3 would be the largest number that can run in series on a 12V supply.

 

[diburning]

I'm going to have to look at the resistor values when I receive mine. The club layout is 14V DCC, with 16V in some spots. I need to make sure the resistors aren't at the bare minimum resistance (possibly to get as much light out of the LEDs as possible?)

 

[videobruce]

John P;
Nice find. That makes the cheapest yet for one of these strips.

diburning;
Yes, they are in parallel which is why you can cut the entire strip into 'three LED's per section' as I stated. If you look at the closeup in the 2nd post, that would answer your questions.
The resister is labeled "151".