bi-color class light

[BradenD]

Hey guys hope you're having a good day. I recently saw a lionel engine with bicolor class lights and my mind was blown. I then thought of using fiber optic strands and running the strand into a drilled out marker light and then power it with a bicolor led. Do DCC decoders have the ability to flip polarity in order to change the light's color? Also are there any flaws in my idea to run optic cables?

[tstage]

Braden,

Somebody can correct me if I'm wrong but classification lights generally signify "direction" - i.e. green on the front end and red on the rear end.  So, depending on which direction your locomotive is traveling will dictate what color it is.  Therefore, you can just have the color aspects of the LED hooked up to the specific headlight functions of your decoder - e.g. green for F0F (white & blue wire) and red for F0R (yellow & blue wire); assuming they don't exceed the max output of the function.

Also, keep in mind that bi-color LEDs come in a few different flavors:

• 2-pin & 3-pin
• Common cathode or common anode

I used 3-pin LEDs for an Atlas H16-44 project.  It actually came with green-red aspect LEDs that changed with the direction of travel.  However, my railroad used white-red so I replaced them with white-red LEDs.  And, IIRC, the replacement LEDs came with a common (-) anode, which is less "common" than a common cathode found on most LEDs.

I ended up replacing the OEM decoder in the H16-44 with a TCS A6X 6-function decoder board, which was a drop-in replacement.  I also took a different approach to how they illuminated.

I wired the front & rear headlights, as usual but wired the front & rear classification LEDs to each of the remaining 4 functions of the decoder.  I then remapped F5-F8 so that I could controll each bi-color independently from one other rather than by direction.  A push of the function button turned a function on and another turned it off again.

F5 & F6 controlled the white front & red rear classification lights and F7 & F8 controlled white rear & red front classificatioin lights.  It also allowed me to turn off the rear classificaton light (whichever direction) if the locomotive were operating in a train.

I have yet to try fiber optics so I can't really give you any help with that, Braden.  Your idea is possible though.  I believe Ed (gmpullman) has some experience using fiber optics for lighting.  I'm sure he'll chime in at some point...

HTH,

Tom

[gmpullman]

Hello,

Let's talk about classification lights. Technically 'three' colors are used. OFF (none), white and green.

These were used to signify weather a train was a timetable schedueled train (none) or an extra train (white) or if the train was running in multiple 'sections', in other words usually a first class passenter train might have enough traffic (tickets sold) to run in mutiple sections each having a locomotive and crew assigned.

The 'sections' preceeding would run ahead of the regularly scheduled first class train and they would display green flags by day or green classification lights by night. The final section, which is running on the prescribed timetable schedule, would display NO flags or lights as it is a scheduled train.

NYC_Class_30 by Edmund, on Flickr

NYC_Class_31 by Edmund, on Flickr

When you introduce red you are no longer refering to a classification light. There is NO red class light, it has become a 'marker light' and is used to signify the end of the complete train. If a tower operator observes a passing train and it is  not displaying marker lights he must not consider the train as having passed as the 'markers' have not been observed.

When a built-in classification/marker on a locomotive is displaying red it is to signify that locomotive is running in reverse (usually in helper or pusher service) or running 'light' (by itself) and that locomotive is considered a complete train since it IS displaying red marker lamps to the rear.

The Red Eyes of Otis by Don Kalkman, on Flickr

Clean Conrail by Don Kalkman, on Flickr

The above two photos show an anomaly (someone is not paying attention) as the headlight is lit as are the marker lights. Is the train coming or going? I've seen cases where the crew neglects to extinguish the red markers as are the cases above. IF the headlight (and ditch lights) are extinguished you could assume the engines are going away from the observer and are at the rear of the train in helper service.

Classification light useage varied by railroad and was pretty much phased out with the advent of CTC signaling systems and other movement authority methods. I recall seeing green class lights used by the Seaboard Coast Line and the Southern Railway in more recent times.

https://www.trains.com/trn/train-basics/abcs-of-railroading/locomotive-classification-lights/

SR 3303 Louisville KY May 1980 by Pete Piszczek, on Flickr

Most roads phased them out in the 1950s, give or take.

Tom is correct that I have messed around with fiber optics for both classification and marker lights in models. More recently, though, the advent of tiny SMD LEDs has pretty much negated the need for the light tubing. Here's a PRR F3 that I just fitted markers to and are controlled by a DCC function for illuminating them:

PRR_F7a-marker-LED by Edmund, on Flickr

This is showing the LEDs before application of a light-blocking tape over the backs.

PRR_F7a-marker by Edmund, on Flickr

Three manufacturers I'm aware of in HO have produced models with functioning class/markers on locomotives, Rapido, Bowser and Scale Trains. Commonly they will use lucite 'light pipes — basically the same as fiber optic, to direct light out the lens(es) from small LEDs on a PC board.

Bowser, I believe, pioneered this even back in the DC days with their Alco Century series where the LEDs shined out of three pairs of lenses above the number boards.

UP 2909 Bowser ALCO Century 630 by Pete Piszczek, on Flickr

Rapido offers functioning class lights on several of their locomotives but to my knowledge they offer only the green and white colors and these can be toggled (off-green-off-white-off) by using a mappable function key. The ESU Loksound decoder is (using the Lokprogrammer) easy to setup this logic toggle feature of the lighting function outputs. ScaleTrains toggles three colors.

NYC_PA-4203-number-nose by Edmund, on Flickr

This is the PC board with the various LEDs applied, two bi-color for class lights and two are number boards and the center pair are headlight and Mars light. You bring up a good point about polarity reversal for switching the color of the bi-color LED. I can't exactly answer how the function output is wired in that case. Scale Trains, I understand, has a way to get red, green and white to show.

NYC_PA-4203-SMD-LED-board by Edmund, on Flickr

Other DCC decoders can be set up so that functions can be mapped to illuminate LEDs for lighting. Evan Designs and probably others have multiple color LED arrays (usually RGB but there may be red, green, white custom made). I use the tri-color LEDs for searchlight signals (red, yellow, green of course)

Here's a Scale Trains video showing the toggle of the class/marker lights:

Good Luck, Ed

 [edit] PS Many of the manufacturers classification lights are simply way too bright to be considered realistic, in my observations.

CBQ-167-C by Edmund, on Flickr

 

 

 

 

 

[BradenD]

Ah I see. Thanks for the valuable information .

[Renegade1c]

I have a scale trains SD-40T-2 that came without a decoder and I installed an ESU decoder in this unit. The White, Green and Red colors are three seperate LED's  for each class light. Each color is a seperate function on the decoder. The logic to cycle the color change is actually saved as a sound function within the ESU decoder. Unless you have a lokprogrammer this can't be accessed. The "sound" file with the logic basically is a loop that goes like this.

 

Count is physical output on the decoder (AUX 1, AUX 2, etc)

In my example the following are the physical inputs, outputs

FX6 = Function 6 on decoder and throttle (input)

Aux 4 = White LED's (output)

Aux 5 = Green LED's (output)

Aux 6 = Red LED's (output)

 

Count Start = 4 // First button will activate AUX 4 (White LED's)

while() //This starts the loop

{

 

-Set FX6 ON -Turn on AUX (Count) //white LED's turn on, count = 4

-Set FX6 Off - Turn off Aux (Count) // white LED's turn off, count = 4 

    -Count= Count+1 // Selects next Aux output

    -Turn on Aux (Count) //Green LED's Turn on, count = 5 

-Set FX6 On - Turn off Aux (Count) // Green LED's turn off count = 5 

    -Count= Count+1 // Selects next Aux output

    -Turn on Aux (Count) //Red LED's Turn on, count = 6 

-Set FX6 Off - Turn on Aux (Count) // Red LED's turn off, count = 6 

-Count= Count-2 // Resets count back to original start value

} //End of loop

 

Honestly what I did is I downloaded a file from the ESU site that stated it had the class light function and updated the hardware inputs within the "sound" file to match the phyical outputs of the Class lights. you then upload this as you would a sound file within the decoder and assign it to your preffered Function output.

Again to get the class lights working with ESU you will need a lokprogrammer. As far as I know this is reason that the ESU decoders are used. I'm not sure any other decoder is capable of handing this type of logic.