DCC++ Arduino power

New kid of a certain age could do with a spot of guidance as to fora etc.Being a fossil I've just found Ard DCC++ which interests me but I have zero experience of the Ard.
I intend to run three concentric cicuits linked by points - all serene. I want to use Arduino DCC++ and will need to use power blocks So each block receives about 5a at 15V.
I assume, and this is where your brains come in, that I will need a seperate PSU - I think roughly 20VDC @10A. Is this roughly correct?

Could you please post a little more abour your trains? Usually modell trains don't need 5A.
And DCC is intended to be able to control different trains independently without seperate powerblocks. Only large railroad layouts need several separate power circuits.

Yeah, that's not normal. G scale trains do use a lot more power if that's what you have. I agree, normally a small or even medium sized layout can use one power block. That one block, however, is often broken down into multiple occupancy detection blocks, or reversing blocks (such as needed on a wye).

Only a hybrid DC/DCC system would actually require multiple supplies, one for each train when using DC.

If you want to use that much current you will need some form of power booster for each block zone. also look at DCC++EX better version of DCC++ each booster will need about 15v 6amp transformers
There are kits available that can supply 5amp or 10amp supplied by MERG each kit is about £28 but you will also need to join MERG 1 year subscription is £16.