Marker Lights

[Freelancer]

I am trying to install some marker lights on my caboose, and am wondering how to do it. I am using a Digitrax Zephyr system, I beleive that it puts out 12 V, some one correct me if I am wrong. I would like to connect the lights directly to the track but I am not sure exactly how to do this, I figure that I will probably need some resistors but I don't know what ratings to use. The local hobby shop suggested that I use a constant lighting mechanism, (I thought that those were just for use on DC) when I connect the lighting mechanism to the rail the lights go on but the system shorts out. The fact that the mechanism doesn't work doesn't bother me, all I want to know is how I can connect these marker lights, with or without this mechanism. Do I need more than resistors to do this task? Oh, and I am using 1.5 V lamps. One more question, what is the difference in a grain of wheat bulb and a grain of rice bulb? and how can I tell them apart?

Thanks, Freelancer

 

[Pete]

An easier (?) way to reduce the 12V down to operate your 1.5V lamps might be through the use of diodes instead of resistors. There are a couple of different ways they can be used. I'll see if I can find some diagrams and post them up later...

Pete

 

[Freelancer]

Thanks Pete, I would appreciate that.

 

[Gary Pfeil]

I'm not sure about the 12 volts from a Zephyr. And you need a special volt meter to read it, since it is neither DC nor conventional AC. Tony's (www.ttx-dcc.com) sells a meter that reads the voltage and amperage correctly. Here is the non technical method I use for determining resistor size for bulbs on DCC: For a 1.5v lamp, try something around 800 ohm first. Just clip the track power to the resistor and lamp. Work your way down till brightness suits you. I suppose since I have access to all the resistors I want for free this method is fine! If you get an accurate reading of track voltage you could just post it here and someone will give you a value. Difference in grain of wheat versus rice is size and current rating.

 

[billk]

Recently there was an article in one of the mags (MR??) where they used a little battery (watch/calculator type) to for something like this. The neat thing I remember is that the caboose's smoke jack was connected to an on/off push button switch so you could turn the lights on and off.

 

[jon-monon]

Perhaps a white LED with a 1K ohm or larger resister

 

[shaygetz]

If you're using the Apex ones, I just made up an onboard battery setup like so;

 

[shaygetz]

The light is turned on and off by a switch routed thru a rear window using a very small nail. It could just as easily be done thru the smokejack as well. No one has yet pointed it out in 8 years of ops. The battery is 3 years old to give you an idea of how long it lasts. I've had it on for 6-8 hours at shows. The extra weight helps the car to track well and the battery will never fry those 1.5v grain-o-rice bulbs.

 

[Pete]

Here's a few diagrams I found that will add some different effects. Also useful for locomotive lighting.
http://home.cogeco.ca/~rpaisley4/xConstLight.html
Of course, an LED with the proper resistor works well too

Pete

 

[Freelancer]

Thanks for your help guys, I think that for right now I will go with shaygetz idea with the battery. It seems to be the easiest for me. For being so electronically illiterate I don't know why I picked this hobby. Thanks again!

Freelancer

 

[shaygetz]

Radio Sham carries the battery box for $.99 if you're not feeling mechanically inclined. You won't be electrically illiterate for long in this hobby:thumb: