Marker light, LEDs, DCC question

[eja]

I would like to install marker lights on the ends of some of my KATO passenger cars.  Although I can change a light bulb, that is almost the extent of my electrical knowledge.

From what I have read in various threads on TRW,  I am thinking that if attached a small LED to the inside of the shell and connected the leads to the electrical pickups inside the cars (with a resister on one side) that I would have a glowing LED!

This sounds too simple, so can anyone tell if this would work. My layout is DCC  rather than DC, if that matters.


Thanks for your help......

eja

[peteski]

Eja,
See https://www.therailwire.net/forum/index.php?topic=31910.msg358079#msg358079 . For DCC you would use the circuit in the bottom diagram (with the bridge rectifier).  Since with DCC you always have full voltage to the track you can also simplify that circuit by hooking the 2 LEDs and a single resistor in series (instead of parallel with 2 resistors as shown in the diagram).

[eja]

Thanks Peteski,

I am not sure I understand everything, but I will try to figure it out.

I don't want to light the car interiors ( it only shows how poor the the revenue service is) but illuminating the trailing lights might add interest as the cars go around.

Anyone else care to chime in ?

[peteski]

Thanks Peteski,

I am not sure I understand everything, but I will try to figure it out.

I don't want to light the car interiors ( it only shows how poor the the revenue service is) but illuminating the trailing lights might add interest as the cars go around.

Anyone else care to chime in ?

Um, I think I gave the wrong link. This should link right to the diagram: https://www.therailwire.net/forum/index.php?topic=31910.msg357598#msg357598

If you don't understand something - just ask. 
The diagram I pointed you to was for the red LED marker (EOT) lights, not specifically for the interior.

[carlso]

eja,

I have no interest in this organization other than knowing Jim Hinds, who I think a lot of, especially his ethics. This is obviously not a passenger car, however I have the same markers on a MT heavyweight car. The light unit is from Richmond Controls. Each marker is actually two Led's glued together back to back.

Thanks for looking, hope you enjoy,

Carl

[eja]

Eja,
See https://www.therailwire.net/forum/index.php?topic=31910.msg358079#msg358079 . For DCC you would use the circuit in the bottom diagram (with the bridge rectifier).  Since with DCC you always have full voltage to the track you can also simplify that circuit by hooking the 2 LEDs and a single resistor in series (instead of parallel with 2 resistors as shown in the diagram).

OK  ... I've done some reading ( dangerous, I know) and I wonder if a pair of zenor  diodes could accomplish the same directional lighting as the bridge rectifier ?

eja

yes, I know a little knowledge is a dangerous thing  ....

[peteski]

Fist of all, why?  Can you give me some specific example of what you want to accomplish with the Zener diodes?

If you simply want to replace the bridge rectifier with 4 Zener diodes, then no.  Well, yes, if you used Zener diodes which had the Zener voltage greater than the track voltage (so they would act as regular diodes like the ones used in a bridge rectifier. But then again,. the question is why?  Zener diodes (on their forward bias mode) do not make good rectifiers.

You mention directional and that you are using DCC. You didn't mention the directional part in your initial question. There is no direction in the DCC track voltage.   The pulses of voltage at the track are non-directional. In order for the markers to be directional you will need a (function only) decoder to drive them. That way the car will know which train (pulled by some loco) it belongs to and direction it is going (since the decoder will be addressed by the handheld throttle controlling the entire train, giving it the direction commands. But in that case you won't need any Zener diodes or bridge rectifiers.  Without a decoder all you can do is constant lighted illumination (like the circuit I pointed you to earlier). 

[eja]

peteski

Thanks for your reply .....

As I originally said, I have a very limited knowledge of electronics, but apparently enough to be dangerous.

All I am interested in doing is lighting the end marker lights in my Kato high level Amtrak cars.   Someone mentioned that to be realistic, only the rear lights should be illuminated and that of course would depend on the direction of travel.

I only asked about the diodes, because I used them many years ago (when I did HO) to make directional headlights on an AHM Pennsy GG1. It worked there and thought it might be applicable to my current project.

Your help and patience is appreciated......

eja 

[peteski]

If you want directional control of DCC lights, you need to be able to tie them to the specific train the car is running in.  The only way to do that is to have the lights controlled by a DCC decoder.   That way you can assign it to the same address as the locomotive pulling that train or put it in simple or advanced consist with the locomotive.  At that points the lights in the car will be given the sense of direction (relating the the train they are part of).

Function-only decoders are inexpensive (you can get one for around $16) and they already contain all the electronics needed to drive the LEDs (sans a single current limiting resistor which has to be added).  But you will also need to keep that cars wheels clean or the decoder won't work very well if there is intermittent contact with the rails (which on DC power shows up as flicker of the car's lights).

[RBrodzinsky]

For the Kato bilevel cars, you can use the Kato FL12 decoder to control end lights. It fits in at the end of the car interiors, and is designed to get the electrical pickup from the conductor strips inside each Kato car.

[nickelplate759]

I just put an FL12 in my C&NW Cab car.  the documentation for the FL12 (https://www.katousa.com/PDF/29-352-FL12-English.pdf)
says that the address can be set from 1 to 9983, but I can't figure out how to do it.  I note that programming on main doesn't work at all.
I can use "programming track" mode on my NCE PowerCab to set a short address.  Is there any way to set long?

The only CV entries mentioned in the documentation are 01 (2-digit address), 61, 64 (both for transponding).

Also, all CVs are unreadable (and the documentation confirms that).

SOLVED!

In Programming mode, write CV29 to 38 (forward) or 39 (reverse) to enable 4-digit addressing.
Then set registers 17 and 18 to the four HEX digits for the desired address.  This tool will calculate the decimal equivalent for you: https://www.ruppweb.org/cgi-bin/webcv?address=400&webcv=Calculate

So for mine (decimal 400), I used CV17 = 193 and CV18 = 144.

The interwebs are a beautiful thing when they work!

[mighalpern]

Hey petski
the drawing is coming out blurred for me, could you re-post it please.
thanks
Miguel

[peteski]

Hey petski
the drawing is coming out blurred for me, could you re-post it please.
thanks
Miguel

Ah, the Photobucket debacle.    Fixed it.