First you need to pickup track power with metal wheels and axles wipers to bring the current inside the car. If the Superliners have factory lighting, then that part is already done. Otherwise you have to make your own wipers. Axle wipers have much lower drag than wheel tread wipers, and wiper drag is a problem, especially if you have grades to surmount. Go with axle wipers.
LED's are polar, they only light when current is passed thru them in the right direction. DC powered track may be of either polarity 'cause switching polarity is how the locomotives are reversed. DCC track power looks like AC to a LED. So you need a fullwave rectifier to create a constant polarity LED drive. After the rectifier you need a current limited in series with each LED. You can use plain resistors, but they will cause the LED brightness to vary as track voltage varies. More sophisticated is to use current limiting diodes, one such diode in series with each LED. You want to hold LED current somewhere between 5 and 15 milliamperes. Or you can use 1.5 volt incandescent lamps which do their own current limiting and don't care about polarity.
Was it me, I'd let the markers illuminate all the time and not worry about a switch to control them.
David Starr www.newsnorthwoods.blogspot.com
I have decided to install some marker lights for my new HO Walthers Superliners. I plan on doing a coach and maybe a sleeper. My only requirement is that the lights have to be track powered because it is a pain to remove the shells and access the interiors. I am going to use LEDs. I was wondering how I would do this.
I want these lights to be able to be turned off/on with a reed switch. I am currently running DC with plans to switch over to DCC in the near future.
Any suggestions?
Will