I'm going to put both headlight (white LED) and tail light (red LED) at one end of a passenger tail car, all connected to a DCC decoder. Can I connect a 1K resistor to the blue wire, then both LED anodes to the same resistor and the other end of one resistor to the white wire and the other end of the other resistor to the yellow wire? I'm guessing that won't cause a problem because only one LED will light at a time. Or should I be paranoid and assume the decoder will be lazy and take longer to extinguish one LED before it illuminates the other?
It's fine. I usually wire my loco headlights that way. It's hard enough putting all that stuff inside.
Use a bigger wattage resistor if you're insecure about this.
It takes an iron man to play with a toy iron horse.
to the forum. Your inital posts are moderated, so there will be a delay before they appear.
I'm not the sharpest pencil in the electrical box, but I believe they will function fine if one or both are lit. You should not notice a delay.
edit member since 2013 and the first post? You don't know what you don't know until you post it and your friends in the forum set you straight. It also helps to think "out loud" and we want to see what you know/do that we don't.
Henry
COB Potomac & Northern
Shenandoah Valley
Well, the safe way is to never assume the decoder can't turn on both at the same time. It would be a simple programming error - say you wanted to make the red light flash like a Mars light - goof up the CV value and yoou set it instead for non-directional, which means botht he white and yellow wire come on when F0 is activated.
Will it hurt anything? depending on the exact details of the LEDs being used, they might still both be below the current limit if both are activated at the same time. So Maybe it is ok anyway.
But all you need are 1/8 watt resistors here, they are quite small, little more than the solder joint in the wire, so why not just put one in for each LED and never ever think or worry about it again?
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinkerBut all you need are 1/8 watt resistors here, they are quite small, little more than the solder joint in the wire, so why not just put one in for each LED and never ever think or worry about it again?
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!