So how have I wired it up? Firstly, this is DC and not DCC. I've experimented with DCC but it is more than is needed for this type of layout. I want automation but I believe I can do it in a simpler manner.
Having used a cheap PWM controller off ebay and using LED strips for the lighting it means all I need is 12V DC. The best way to provide that is with off the shelf supplies of the sort that come with all sorts of electrical kit. I'm temporarily using a couple that powered a BT router. Eventually there will be 3 of these powering the layout:
- The overhead lights will have their own supply. They don't take anywhere near 2 Amps but it seems to be wise to keep this separate.
- The track will have it's own supply.
- The servos will also have their own supply. These aren't fitted yet but reading the internet you can find plenty of reports of interference so, again, keeping it separate is a sensible precaution.
I've ordered 4 supplies off ebay. I suspect they are coming from China but that's fine. They will be double insulated and acceptable to exhibition electrician approvers who seem to be often nervous of anything home grown. I've noticed that when they see off the shelf kit they sign it off because there's nothing for them to check. I like having a spare available, hence the 4th supply. By having 4 identical supplies they have identical connectors so are all interchangeable.
The layout is on 4 boards. The fiddle yard has most of the wiring so that's where power goes in and where the track feed comes from. I wanted robustness yet flexible connections between the boards. In the end I settled on 3.5mm jack sockets on each board and purchased some 1m cables ready made. They are a very low price on the internet. Again, I need 3 cables so I bought 4, all interchangeable and a spare.
I was initially concerned that the cables would not carry the track current but with modern motors it is so low I am not seeing any obvious problems, no drops in speed except where the track is tight at the bends and that is down to friction and not power distribution. I shall leave it running a long time and see what gets warm.
The sockets are all bolted into aluminium brackets. I had some long runs of aluminium angle and it took all of 30 minutes to cut and drill the brackets.
At some point in the future I'll wire up the servos but for now I am going to progress the scenery.