I'm now wiring up the blocks on my Digitrax controlled layout. 



However, most of the other supporting components require separate power feeds.



These are, 2 x UP5 Face Plates, 2 x UR90 IR Face Plates, 2 x BDL168, 1 x PR3, 4 x DS64 and 2 x SC8C.



Oh, and I'm about to buy a PM42. (I should have bought shares in Digitrax)!



Have most modellers installed a 15V DC circuit to power these items?




Regards Charlie

There are a couple of things to consider regarding this. I don't have the accessory decoders like you do at the moment as my points are cobalts so take power off my accessory bus.The PR3 only requires a power supply to work as a programmer. It takes enough power from the USB to connect to your command station via loconet if you run it purely as an interface. The UP5's only need a power supply if you intend to charge controllers through them. The UR 90's require power for the wireless capabilities to work. All other modules need power at all times to work is my understanding.Digitrax offer 2 power supplies the PS14 or PS2012. I decided not to use either of these and bought from maplin a desktop variable power supplyhttp://www.maplin.co.uk/p/maplin-36w-switched-mode-dc-variable-voltage-compact-bench-power-supply-l10br?gclid=CjwKEAjwycaqBRCSorjE7ZewsmUSJABWzM54dE9GYahMa_w1sdQ-4nUgcy6fHYuAs9IVpKN-sSDrYBoCQQLw_wcB
It can cope with up to 3A of current drawn so keep an eye on how much current you need for all your digitrax and other parts. Most of them draw about 0.1-0.3A I have run a 12V "bus" around my layout which is fed from this and then the various units are connected to this bus including a USB connector I have installed which keeps my phone charged :D
The blue + white are my 12V Feed in the below pic (old pic lot done since).

I don't think 15V is needed as the recommended PS14 is 14V but it only provides 0.3A so you would need multiple of these which is why I decided to get a bigger supply. Everything has been working ok so far off the maplin one but it doesn't seem enough of a kick to power the PR3 in programmer mode but I don't use the PR3 in this mode.

Thanks Vonk, I'll be off to Maplins at the weekend.