I want to replace the lights in my Aristo passenger cars with LEDs. I bought a string of lights from HD. The LEDs are rated for 3.8V each. I will put the battery in the baggage car and run buss wires through the 4 cars. How many LEDs are required for each car and can I use one LED driver for each car. I have a Li-ion 11.1V 2600mAh battery, will that be enough?
Louis - you may find some information to answer your questions in this article on my web page
http://www.trainelectronics.com/LED_Articles_2007/LEDs_for_Coaches/index.htm
please let me know if you have any questions
dave
Thanks Dave. This will be a big help.
Lou
I put LED’s in 2 old time passenger cars. I put 6 LED’s in each car. I put 3 LED’s in series and hooked the pairs in parallel with an appropriate current limiting resistor in each string.
Whe you hook additional cars, you must make sure that the polarity is correct when the cars are hooked up. In my case, instead of worrying about polarity, I put a bridge rectifier in each car to ensure the polarity was correct.
Your battery should last a long time between charges.
Bill Swindell said:
I put LED’s in 2 old time passenger cars. I put 6 LED’s in each car. I put 3 LED’s in series and hooked the pairs in parallel with an appropriate current limiting resistor in each string.
Whe you hook additional cars, you must make sure that the polarity is correct when the cars are hooked up. In my case, instead of worrying about polarity, I put a bridge rectifier in each car to ensure the polarity was correct.
Your battery should last a long time between charges.
If you just add a small bridge diode to the input power for the LED’s the polarity issue will go away.
The two wires marked with the ~ are connected to the track and just connect the + and - wires or pins correctly to the LED circuit
If you use an LED driver, you donot need to be concerned about the number of LEDs in the train. I have between three and four LEDs in each car in a six car consist I can run one to six cars at a time. The power pick up is in the baggage/combine, and feeds all cars with small wires that actually look like air hoses.
My circuit for power picks up from the rail, contains a rectifier (so current always goes in the same direction, regardless of which direction the train is going) a big capacitor so the lights stay on when the train hits a dirty spot, and the LED driver I got from Mouser. I made so many of them for friends (they can be used in trains, buildings, etc, and can be powered by ac or dc up to 25 volts) that I had some printed circuit boards made, which really simplifies the construction. I always wire my LEDs in parallel, which may simplify your wiring. I run a pair of 14 gauge bare wires the length of the car, and put the positive LED wire on the same side all the way through. The small connectors (micro-something) have connectors with dots on them, so you keep the polarity through the cars.
This kitbashed diner has four LEDs in it, powered by my circuit and connects to the rest of the train by small wires. (http://freightsheds.largescalecentral.com/users/dick44/smkitbasheddiner.jpg)
I will be putting the LEDs in a old set of Aristo smooth side passenger cars. I was thinking 6 LEDs per car which would require a 24v battery per car.
You do not have to put all of the LED’s in series. If you put 3 in series with the proper current limiting resistor. Then hook the 2 sets of 3 LED’s in parallel. This hookup will run on 12v.