Patrick - you could certainly use the 3rd channel for a 2nd relay or any other purpose you might come up with - lots of options!
dave
I wasn’t going to show this until I could test it but since the subject came up here and on another thread I though i would throw it out there.
I ran this by Dave and he seemed to think it would work. I am still waiting for my LED controller to arrive from China so I can test it out. The idea was to expand on what Dave had come up with. Its purpose is to provide forward and reverse lights that are directional with locomotive travel. It adds a SPDT relay triggered by the same wire as the other relay. This will provide the directional element as both coils energize or deenergize at the same time. Each leg of that relay then lights its respective lamp.
In addition I added things like plugs, fuse, main on/off switch, light on/off switch, battery and motor connections.
Once the LED controller arrives I will buy the other components and get this put together and see how well it will install in a little big hauler.
Edited to include that with this set up, if it works like I think it should, the lights would be constant brightness and not dim with speed. This still leaves DYI 3 open for some other purpose.
This is exactly what I had in mind!
I also ordered two of these units. (In case I blow one up)
I plan to first run led lights with one as intended to see what the other controls do and if they could somehow be useful for our purposes.