# Lighting HO scale passenger cars - Need suggestions and guidence



## johnfm3 (Sep 30, 2016)

I am trying to install lighting in my passenger cars, and am finding way too many options. Based on what I have read, some i like and others dont sound that interesting. I know in the end I want each passenger car to be controlled by a decoder. Ideally a decoder supporting 4 functions.

My first choice is to purchase the DigiKeijs DR80010. With 12 LEDs in 4 sets of 3 in sequential order. Each set interdependently controllable including on/off/fade (on/off)) all dcc controlled. As well as the entire bar can be controlled as a complete set of 12. A consist can be created of all cars for uniform control. The only pitfall is NO smaller bars for stuff such as mail cars. And there is no good solution for Vista Dome cars which need separate segments.

I have looked at other solutions which require building and installing seperate decoders. I am ok with this, but I really like the ability to control sets of LEDs as well as the whole bar. And here is where I get into trouble, other than installing 12 individual LEDs and running all the wires, I have not found a good/clean solution. I would be willing to pay for printed circuit boards where I solder Surface Mount LEDs and a decoder.

I dont believe that I can get a good idea based on reading and I am asking for advice for a cleaner solution.

Ideally I want all my passenger cars to have the same dcc solution.

Suggestions?

Thanks ~ John


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## DonR (Oct 18, 2012)

The best and easiest way to light passenger cars is to use 
the LED STRIP lights. They come in a roll of a hundred
or so. The roll is marked off in 3 LED sections. Use 2
sections for each car. Each of
those runs on 12 V DC which is the light output of DCC
decoders. The sections have a 'bus' so you need
connect only one to the decoder. These strips have adhesive backing but I
would add a dab of glue just in case. 

These come in various colors. Warm white produces light
that is similar to florescent tubes, ideal for your purpose.

Use the 'left overs' to light buildings.

Don


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## gunrunnerjohn (Nov 10, 2010)

Note that running the LED strips at 12V does two somewhat undesirable things, at least for me.

#1, the output is way to bright for a passenger car, especially a small HO sized car!
#2, the current draw of a strip of these will likely be more than the engine pulling them is consuming at 12V to the LED's. 

For O-gauge 18" passenger cars I light them with about 25-30 milliamps total current through a 16" strip of lights, they're plenty bright with nice even lighting.

For use with the 12V decoder output, I'd add a series resistor to reduce the current and intensity, at least if I were doing it.


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## johnfm3 (Sep 30, 2016)

gunrunnerjohn said:


> Note that running the LED strips at 12V does two somewhat undesirable things, at least for me.
> 
> #1, the output is way to bright for a passenger car, especially a small HO sized car!
> #2, the current draw of a strip of these will likely be more than the engine pulling them is consuming at 12V to the LED's.
> ...


I understand all this. The need for resistance and current amount is not the issue. The decoders I have researched can provide a total of 500mA across 4 functions with no function using more than 250mA. Considering the average LED uses 20mA with calculated resistance of 150ohms each, and we are only talking about 4 functions with 3 LEDs each, I have plenty of room for adjustment of resistance affecting the current of each function.

The concern I have is more about ideas for a clean install. Ideally with the capabilities of sequential LEDs as shown in the DigiKeijs board that I can use across all sizes of passenger cars.

I have reached out to Motown Models to see if they would solder sets of 3 nano LEDs (surface mount) in parallel for me with a 4 inch separation for a clean install. i have also considered mocking grab bar out of copper just about the windows on each side to run the led wires too.

The electrical side I have a concept on, its the physical install side that is blocking me. And seeking advise on making that clean install, ideally with printed boards.

John


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## gunrunnerjohn (Nov 10, 2010)

I have to believe that the printed board format would be somewhat dependent on the specific cars you're illuminating.


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## johnfm3 (Sep 30, 2016)

gunrunnerjohn said:


> I have to believe that the printed board format would be somewhat dependent on the specific cars you're illuminating.


Correct. And thats why I am asking. That is the downfall to DigiKeijs, they dont provide other solutions than the one. I dont mind custom if there is a option. I am searching for the solutions others have used to see what I want to do and see if my wants can be supported by the suggestions.


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## gunrunnerjohn (Nov 10, 2010)

Makes sense, since I don't have HO cars, I'm probably of little help.


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## johnfm3 (Sep 30, 2016)

gunrunnerjohn said:


> Makes sense, since I don't have HO cars, I'm probably of little help.


I dont believe that is true. I know how to throw leds and a decoder in my cars and get them lit. But if I do it, there will be wires all over the place and it will look trashy. And after making it a point to purchase full interiors, I don't want wires running all over trying to wire 4 circuits of LEDs, assuming that's possible. If I wanted a single set of lights, this would be very simple and cheap to do. What I am asking for is suggestions on clean installs with LEDs going to 4 separate functions. And options for printed boards, or pre built led bars sold at model railroad stores.

Thats what this thread is about. And if I get no answers, then I will be blazing a new trail and documenting it.

John


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## gunrunnerjohn (Nov 10, 2010)

Well, I doubt you'll find boards that would suit your purposes at model railroad stores. This sure sounds like a custom board job. On that score, I actually have a bit of knowledge. Maybe even quite a bit of knowledge.  I've laid out dozens of boards, some pretty involved. The trick here is coming up with the outline of what will do the job, and what connections it has to support. First step would be to draw a schematic of what you would like the board to do and exactly how it would connect to your power source or sources.


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## johnfm3 (Sep 30, 2016)

gunrunnerjohn said:


> ...On that score, I actually have a bit of knowledge. Maybe even quite a bit of knowledge.  ...


If this is something your interested in tackling, I wouldnt mind a phone call to talk possibilities and numbers.


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## gunrunnerjohn (Nov 10, 2010)

Truthfully, I really don't have the time, but I can at least provide some guidance in accomplishing the task. Like I said, you need to identify the scope of the problem first. I'd recommend tackling this just like a real commercial project. The first step is documenting the requirements for the board or boards. What you certainly can do is decide what shape and size the boards need to be to fit into the various cars, and also where the LED's would be on those boards. Also, you mentioned having multiple circuits to the boards, is that for diming, lighting just sections, what?


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## johnfm3 (Sep 30, 2016)

Thanks for the interest. I would rather speak about this over phone to more effectively explain what I am envisioning. If you search for the listed DigiKeijs setup, it would be perfectly clear. As you dont have the time, I need to keep looking. I have the knowlege (7yrs of education in Electrical Engineering 3 in HS and 4 in college), but not the tooling as I ended up working in IT at Microsoft. And the cash to update my CNC router (X-Carve) for the task can be better used replacing my layout as I am getting ready to build new bench work this winter. I am finally tearing down that old layout I have shown on the forum.

It really seems like I will have to do away with a board and just run 4 sets of 3 LEDs down the center of the large passenger cars, and 3 sets of 2 LEDs down the center of the smaller cars.

F# for function pad on decoder
L# for LED number
F1L1 - F2L1 - F3L1 - F4L1- F1L2 - F2L2 -F3L2 - F4L2... and so on.

With this, when I turn on LEDs function for a 12LED configuration
F1, LEDs 1, 5, & 9
F2, LEDs 2, 6, & 10
F3, LEDs 3, 7, & 11
F4, LEDs 4, 8, & 12


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## gunrunnerjohn (Nov 10, 2010)

OK, I guess I'd suggest you keep looking. I really don't have the time to research and design this.


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## johnfm3 (Sep 30, 2016)

gunrunnerjohn said:


> OK, I guess I'd suggest you keep looking. I really don't have the time to research and design this.


No Problem


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