Hello, I am beginning my first DCC wiring in an engine. It seems pretty straight forward, especially if I had a DCC system that operates additional functions beyond lighting, such as any of the Digitrax systems. But, I have an old MRC Command 2000 system that works perfectly fine, but does not support additional functions beyond directional lighting. Well, in my first project ever, I have decided to add a Beacon light that is a flashing yellow LED. I would like this light to be on any time the engine is in use, or if need be, have it be on any time it is on the track with power. Using the Digitrax decoder, it has a fourth function wire where this LED would normally be connected, however with my system, this fourth function is not supported. So, I am wondering how I should wire this beacon LED so that it functions with my out of date DCC system, or do I really need to spend around $500 for a new system? If I purchase a new DCC system it will be a Digitrax system with a hand held controller that is not tethered to the control box. Radio or infra system, as If I have to put out hundreds of dollars I may as well give myself some freedom of movement. Any suggestions or help, so I don't have to buy a new DCC system would be fantastic! Thank you.
Does this flashing yellow LED have a built-in flash? In other words, is all you need to get power to it?
If so, and you want it to be on all the time, you can do what is sometimes called half-wave wiring. Add the proper resistor to the LED, then bypass the decoder and wire the LED's cathode and anode to the opposite rails. It may be easy to tap into the power pickups already in use. This will leave the light on all the time. Assuming it flashes when it has power, it should be flashing.
I have the headlights on a Russell snowplow wired like this. They'd always be on in use and I can add an on-off switch if I want to turn them off.
Mike Lehman
Urbana, IL
Thank you. I had thought that I might need to wire directly to the power pick up wires on the engine. Thank you for confirming it for me.
1) Wire your flashing light to the decoder's fourth function output.
2) Take your loco to a friend or shop with a DCC system capable of turning that function on.
3) Have them turn it on.
4) Bring the loco back to your layout (with the fourth function still turned on) and run it.
Thank you. After discussing this with a friend this is what he told me to do. It seems we have a computer with the digitrax system for programming at our club and he will program my chip for this as you have suggested.
Actually, if you wire the light to F1, you should be able to control it with your Command 2000. The Accessory button is supposed to control functiion 1.