I want to use Soundtraxx sound decoders, but they only offer 4 light functions. I would like ditch lights at both ends of my locos. How can I add more? Another function decoder? Multiple lights on one function?
TCS makes the FL2 and the FL4 light function decoders, which have 2 and 4 functions respectively, for just such situations.
What else are you using the light functions for? Do ditch lights take 2 each, because of the alternate flashing?
You can put multiple lights on one function, particularly with LEDs which don’t draw much current.
I would like headlights front and back and working ditch lights on each end of the locos. this equals 6 total functions. I think I may go with multiple lights on one function for ditch lights. It’ll mean the ditch lights on each end will work at the same time.
If I use LEDs, i would have to use resisters to lower the voltage?
Most likely, but check the specs on the decoder. So far, I’ve used 1K resistors on pretty much every LED I’ve installed. No ditch lights in my era, though, so I’ve never done those.
Dave.
Adding a 2 function decoder for the additional ditch lights would be better than all four lights flashing at once. I am not positive but I had heard that the new Quantum Titan decoder will feature six functions. They should be released soon.
Pete
You could also install a small 2 function decoder and match the address. Have the small decoder just do the additional ditch lights.
One option would be to configure the two ditchlight function outputs to be directional. That way the ditchlights will only function in the direction the engine is travelling … which actually makes perfect sence !
Mark.
I was wondering whether that would work. I suppose it depends on how those CVs are implemented. Has anyone actually set up lighting that way? That’s actually the way the front and back headlights work, but they may be a special case.
Sure, but only if they are on different functions.
He would still need a couple of extra function outputs for that to work.
Right - if he wants them to flash alternately. One last option (that I’ve used once) is to add a sub-miniature DPDT relay (they are about the size of a 1/4" cube) that would be turned on/off by the front and rear headlights. The ditchlight functions would be wired through these two relays to send the ditchlight functions to whichever end of the engine the headlight is on at.
The ditchlights are completely turned on/off by the function keys as per normal, but when on, they will only work on the end of the engine that has the headlight turned on - which may be either front or rear or BOTH if the headlights on both ends are turned on.
It requires a bit more wiring, and the two relays take up a bit of space, the the results are rather unique in the way they function.
Mark.
I like this idea, but do you have room for a second decoder?
Rich
I did this for two of my locos, only to find out later that UP don’t flash their ditchlights, so I could have just one output for front and one for the rear ditchlights, I do that now!
The relays are mounted under the pcb in front of the white Soundtraxx decoder
Mike Ruby
I’ve seen prototype locos with ditch lights flashing on both ends.