Caboose marker lights

Matt, I have done this same mod on a few cabeese. I use 4 diodes. Wire two pair in series. Then wire the pair in parallel back to back. These 4 get wired in series with the interior lighting. The Tomar lamps are wired across the diode pack. The diodes drop ~1.5 volts. The back to back pair is required for AC power or DC if wanted them lit forward and reverse. Common 1N400x diodes work where x=1-8. The last number is the max reverse voltage times 100.

Pete

Thanks Pete.

Matt, Here is an example. This technique gives essentially constant intensity.

Pete

That looks great.

I'll post a photo of mine when the caboose arrives and I get the markers installed.

Kind of cheating scalewise, but here is a photo of HO Tomar marker lights I installed for some Santa Fe cabeese on my HO layout:

Just thinking here, but with 4 diodes is this essentially a bridge rectifier? 

Not sure if this is the same thing, but I've used bridge rectifiers in the past for a reverse loop with trains that only travel in one direction.

While the bridge rectifier has 4 diodes the arrangement is different. In a bridge the diode pairs are not wired back to back. The two series pairs are wired in the same direction rather than the opposite direction. 

Pete

Thanks Pete.

Never knew how a rectifier was lined up.  All I knew is it had 4 diodes.

Matt, Here is a circuit that uses a bridge rectifier. By shorting the positive to negative terminals you achieve the same circuit as using 4 discrete diodes.

Pete

Pete"s Method is good if you want to leave the incandescent bulb in the caboose. Another way is to use a Cl2-N3 chip. Shown here for a head lamp, but you could wire 2,red LEDs in series instead.

www.jcstudiosinc.com/BlogShowT...=619&categoryId=

You could also use LEDs for general caboose lighting,described here

www.jcstudiosinc.com/BlogShowT...=487&categoryId=

Dale H

I'm a little challenged when it comes to this stuff. Try this site

 www.royztrains.com    Roy is very helpfull answering your questions. The site has instructions for a few installs that may help.

Small correction, the last number is not the reverse specification x 100.

The 1N4001 is a 50V diode, for instance.  The 1N4003 is a 200V diode...

Marty, I used diodes because the marker lamps I used were 1.5 volt incandescent lamps.

For LEDs I would use the LED driver that Dale shows. The C12-N3 device.

Pete

Thanks Norton. I may just to find an expert to do this. I'm to covertable with all this electrical stuff.

The one's I installed:

 Tomar lights, 807L (LED)  should come complete with a small bridge rectifier and (2) dropping resistors, one for each LED.  I installed a couple on a tail end of passenger car.
807L
ADLAKE MARKER LIGHTS G-G-R.
Brighten the end of your train by adding
these markers to your observation car
or caboose! Kit includes two brass
marker with lens and 3V LEDs installed,
bridge rectifier and dropping resistors.
Markers can be track or battery powered.

LED between the Red and Blue wire.  
Bridge rectifier to the right. There are two dropping resistors one for each LED.