Model Railroading > Ditch light dilemma

so

how am I gonna get ditch lights to light up on my athearn sd40-2. What are my options, with bulbs i know I'm going to have to drill through the body somewhere but there does not seem to be enough space to allow for bulbs to go under the shell and into the inside are where the motor is. HELP!!! Options and suggestions are welcome! Keep in mind that these need to be 1.5v because thats what the voltage is for the posts on the athearn circuit board.

try golden white surface mount LED`s from Richmond Controls. Mount them behind an MV lens in your ditch light housing. They are super bright. Part # GW0630. They also work great for headlights.

http://www.richmondcontrols.com

TWL

J_deBroux Wrote:
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> so
>
> how am I gonna get ditch lights to light up on my
> athearn sd40-2. What are my options, with bulbs i
> know I'm going to have to drill through the body
> somewhere but there does not seem to be enough
> space to allow for bulbs to go under the shell and
> into the inside are where the motor is. HELP!!!
> Options and suggestions are welcome!

keysubdiv Wrote:
-------------------------------------------------------
> try golden white surface mount LED`s from Richmond
> Controls. Mount them behind an MV lens in your
> ditch light housing. They are super bright. Part #
> GW0630. They also work great for headlights.
>
>
>
> TWL
>
> J_deBroux Wrote:

I've seen and tested these LED's too. All I can say is they are PERFECT for model railroaders. They are the smallest LED I have ever seen, and are VERY bright! The only down falls I've found is you will probably need a voltage regulator in the circuit, and they are a bit more expensive than your run-of-the-mill bulb or LED. Don't freak out though if you have little or no soldering experience. Their wiring diagrams are very clear, even for the beginner.

For anyone needing lights in a VERY small space (high mounted ditch lights for example), these will be perfect!

-Brian-

You can also get a very nice selection of LEDs from ngineering.com for not only white but many other colors. There is a picture of one of their LEDs being used to light a hand lantern on an HO scale conductor!

http://ngineering.com/HF2.jpg

Marker lights are easy after that!

http://ngineering.com/HF3.jpg

TB

What happened to using Lucite strands for fiber-optic lighting of small areas such as this? Lucite rod or strand transmits light to the end cut of the material without showing light along its length. Our kids have a little Christmas tree they plug in that is nothing but these Lucite plastic strands eminating from an enclosed light bulb area, and they do light up very bright at the ends like a thousand tiny ditch lights, and with no heat transfer. Advantage is no light bulb change-out inside the tiny housing that is a ditch light. I don't believe one can do a sharp bend, however, only gradual bends. Might this be the limitation? Or could one use the housing itself, clear on the inside and painted on the outside, to transmit the light to an unpainted area on the front of the housing that is scale light-reflector size? Have been curious why this has not been done commercially, bulbs or LED's seem like overkill. - - - - - JLH

> bulbs or LED's seem like overkill.

Using light tubes (when you can align the tubes) works well, as Kato has shown in their ditch lights. Using LEDs instead is really pretty easy. A white LED running at a safe value of about 5mA will work forever, is very bright and makes insignificant amounts of heat. No need to fuss with light tubes.

TB

Hi!

Heres how to use LEDs in a low voltage area:

http://www.maxim-ic.com/appnotes.cfm/appnote_number/1037/CMP/WP-33

TB

I've been playing with ditch-lights on HO locomotives for awhile and have discovered some things.

The simplest way to do it is to use the Details West top mounted ditch light housing. Drill the housing out and a Miniatronics 1.5v 30ma bulb will fit just nice inside. If you drill a small hole in the top of the anti-climber and then one horizontally directly under the anti-climber the wires can be routed right into the locomotive. The issue is that the bulbs are designed to be at their brightest when viewed from the end. As ditch-lights they are viewed from the side. You can drill out the Details West housing enough so that the bulb filament is even with the housing opening. That helps increase the brightness.

Now, I have also been experimenting with Richmond Controls sunny white surface mount LEDs as headlights. I have to say that I absolutely love these as headlights. They are super bright and look awesome in pictures. There is an issue though, when you solder on wire to the surface mount LED (yes it can be done) the wire makes the LED to thick to fit into a Details West housing. You are stuck with using magnet wire which is in my experience difficult to solder to.

What I am going to try is flat flex cable. I'll report on the results when I try this method.

Other ideas I've had include using the Details Associates top mounted ditch-light housing with the surface mount LED mounted behind it. Then wire it using a circuit trace pen. Once the trace dries it can be painted over.

I have had great success using the surface mount LEDs as headlights and end mounted ditch-lights wired with leftover wire from the Miniatronics bulbs. You could also use leftover DCC decoder wire. When soldering to the surface mount LED, definitely use a liquid flux and a good quality sharp pointed tip soldering iron. It takes some practice but it can be done.

Since I use DCC I wire the surface mount (or 3mm) LEDs to a 750 ohm 1/2 watt resistor and this runs them at just under their peak output. You could go as low as a 680 ohm 1/2 watt resistor but you probably won't notice much difference in the brightness.

I would use the 750 ohm 1/2 resistor with these LEDs if you are using simple straight DC. You may want to install a 1N4001 or 1N4002 diode to protect the LED when the polarity reverses. The LED won't burn out since it is resistor protected but the headlight one might flicker when the loco is in reverse and the reverse light might flicker when the loco goes forward.

Hope this helps. Feel free to e-mail me offline if you need more info.

Rio Grande Fan
Denver, CO

> You are stuck with using magnet wire which is in
> my experience difficult to solder to.

If you tin the LED first, magnet wires are a breeze to work with...

TB

also use liquid flux and a low voltage needle point soldering iron. I got mine from ngineering.com

TWL

tburzio Wrote:
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> > You are stuck with using magnet wire which is
> in
> > my experience difficult to solder to.
>
> If you tin the LED first, magnet wires are a
> breeze to work with...
>
> TB

tburzio Wrote:
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> > You are stuck with using magnet wire which is in
> > my experience difficult to solder to.
>
> If you tin the LED first, magnet wires are a
> breeze to work with...

Yeah, I agree :) I use magnet wire for signals, as it takes some pretty thin
wire to route 6 or 7 wires down a brass tube.

Well, that'l work, but it is gross over kill for model trains! All you need is a resistor, 820 or 1000 ohms on each LED and you are good for DCC or DC (you should have a reverse diode across the LED in DC to protect the LED).

Barry Draper

tburzio Wrote:
-------------------------------------------------------
> Hi!
>
> Heres how to use LEDs in a low voltage area:
>
> http://www.maxim-ic.com/appnotes.cfm/appnote_numbe
> r/1037/CMP/WP-33
>
> TB

I'll give the magnet wire another chance using the tip to pre-tin the LED.

Thanks for that tip guys!

Rio Grande Fan
Denver, CO