LED’s for Locomotives and Rolling Stock….

…Or….

WHAT COLOR IS WHITE?!

 

 

This research was borne out of frustration.  I had replaced a dozen lights on various locos and the engine terminal ended up looking like a Christmas tree.  Was fed up with what people called 'white' LED's and set out to sort out a solution.  Soooo…. Over the past year (OK, longer), the GNW has gone a bit crazy trying to find SMD LED's that that that right color to them to simulate the  'halogen' white color of diesel locos produced since about the 70's.  We took all the different SMD LEDs collected over the past
year and put them together on a PC board test strip in a way that clearly shows the differences between LEDs and colors.

 

 

 

There is also a spreadsheet that summarizes the source, model number, color and other info:

 

CLICK HERE

 

Note that the strip is two rows of about 20 columns. The spreadsheet is set up with column references counting from left to right, 1 through 20.

 

Of course, colors are hard to reproduce, so I tried as best as possible to get a couple photos that capture the actual color of the LED. In  reality, they are all VERY bright. So if you are looking for that 'glint' off the railhead, any of these will work fine. I also included a couple standard colored LEDs for color reference - blue, red, yellow and green. That should help with determining standards. Also I included one photo more underexposed to exaggerate the color shifts.

 

 

 

Another point to make is the colors on white LED's are really sensitive to  current flow. In other words, expect some color shift in these as the current drops or increases. For the sake of commonality, all LED's are powered through a 1K resistor, with the exception of the 5050 LED which is around 800 ohms. Note that 0603's are going to be uber-bright with 1K, but many of the PLCC2/3528 LEDs are just getting into their groove at that current flow. All LED's are powered by a common 12 VDC power supply. I used SMD resistors for all LEDs except, again, the 5050. All in all, 34 LED's are compared. Yes, the board does get nice and toasty!

 

If you have pulled up the photos, let me share a couple observations:

Love the 0603's for small areas. However, for headlights, I am preferring the PLCC2 packages. I installed a few 0603s directly in the headlight casting and am finding the rectangular appearance of the LED annoying. With a PLCC2 package, it can be easily installed behind and fully cover a typical light tube. That said, I have had a blast installing 0603's as step lights on a few locos. Wow, does that ever make a difference! A lot has been shared about 0603's, and they certainly are great for where they are appropriate. But don't forget some of the bigger brothers and sisters of the 0603 - they have their place too!

 

How hard is it working with these beasts? Frankly, if you can solder to a typical solder pad on a decoder board, you are more than set to get into SMD's. I only lost 2 LED's in building this board: one flew away when I knocked the package as I was dropping out the LED, and the other I accidentally broke when holding it down with an Xacto knife.  Trick with 0603's is getting leads onto them.  It's really not hard once you had some practice.  You will need #34 or #36 ga magnet wire for the leads, regular or even "DCC hookup" wire will be too big to solder to the pads.  There is a great YouTube vid on how to solder to these little buggers:

 

http://www.youtube.com/user/Gerrymmr - p/u/14/xhe7voGfzpg

 

I also included a few LEDs coated with Tamiya clear coats; 0603 Warm Whites and 0603 Bright Whites. The bright whites are VERY blue, so coating them just added the coat color to a blue color. That said, the warm whites took the coat remarkably well, making very warm colors.

 

A couple other points are:

·        "Warm white" is not always the same. I was absolutely disappointed with SatisLED's WW - it has a very yellow-green hue. In contrast, Ebay seller HiTechLEDWorld's WW 0603 is fantastic. Scan through the photos and you can see most are labeled warm white, but they are all definitely different in color.

 

·        Miniatronic’s T-1 “YeloGlo” has a definite green hue.  This is actually what started this whole program – I did not like it.  The first replacement LED that I liked is shown just to the right of this one – an LED from TOPBRIGHT88, another Ebay seller.  Much better price and color.

 

·        Included in the test setup are three "temperature rated" PLCC2 LED's from DigiKey: one each rated at 2700K, 3000K and 3500K. I put one of those 2700K LED's in my steamer and, wow, it looks good. Like an older incandescent lamp.

 

My personal favorites:

 

• For the 0603, clearly the best "halogen" headlight white are the LEDs from LEDBaron in Germany. I have not found a source for these puppies in the US. LEDBaron is fast and very reasonable in price, so it's not much of an issue.

 

• For an incandescent 0603, your best bet is Ebay's HITECHLEDWORLD "warm white". Note that not all warm while LEDs are the same. Look at the chart and you will see a lot are called warm white, and they are all different in color. I might add, I have about 1,000 SatisLED 'bright white' LED's that are distinctly blue... that are now just in a dead-pile. Anyway, HIGHTECHLEDWORLD has one that is a great color and the price is right.

 

• If you are looking for a 3528 style, which frankly works much better for headlights as they have a bigger 'surface' that projects light, go with HITECHLED's 3528 SMD Warm White. Excellent color.

 

• My favorite all-around headlight LED light comes from Digikey's PLCC2 warm white. They are just a little smaller than the 3528's and put out an excellent color. Thing is, they are the most expensive of the group: about $0.27 each. Smoke one or two on an install and it can be frustrating. But they are nice.

 

• If you want a T-1 style, the BUYNOW360 Ebay seller has a great white-white LED. It is incredibly bright and a very pure white color. I have noticed that if I run this light through the lexan lenses in a loco, a slight green tinge appears. Most people would never notice, but it is there. Not sure why. Jim Betz turned me on to these.

 

Anyway, rambled long enough now. Take a look and let me know if you have any questions. Hopefully this is helpful to people. Standard disclaimer – I have no interest in any of these sellers or companies. I just got tired of buying LED's for my locos and not liking how the color turned out. As it turned out, I probably contributed to the wealth of some of these vendors more than I intended.  So, might as well share what I learned.

 

 

 

 

 

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