Reading a thread here about the problems of powering locos across dead sections of track gives me an idea. I may not be the first person to have come up with this, so let me know if you've heard this before. It also may be impractical for several reasons, discussed below, but I still think it's an interesting idea.
How about building a DCC decoder that uses battery backup for both itself and any powered functions (motor, lights, etc.)? Actually, rather than modifying the decoder itself, this could probably be designed as a power-handling "front end" to the decoder. Here's how I envision it working: it would use a small 12-volt rechargeable battery, which would power it and the loco. The power module would take care of keeping the battery charged from the track voltage, when available, and would draw power preferentially from the tracks, when available.
But when track voltage disappeared, the battery would be used as the power source. So instead of being able just to go over short sections of "dead" track, this could potentially power a loco over good-sized sections of track without power.*Problems*
- The battery and power module would have to go somewhere. I'm seeing a rechargeable battery about the size of a 9-volt battery. This would work fairly well in a steam loco, where the battery and the power module could go in the tender. But in an N-scale diesel, forget it.
- What happens when you shut your layout down at the end of a session? The power module, seeing track power go to zero, would kick in and possibly drain the battery. Not a show-stopper necessarily, but not a good feature. Either it would have to be shut off manually with a switch on the loco, or possibly through the decoder, by sending it a special "shutdown" command. Or there could be a timeout timer that would shut the whole thing down after a short interval.
So whaddya think? Should I pitch this idea to Digitrax?