Wiring Scheme - Advice on alternative versions // Great Lakes RR updates

I like your track plan.  It also looks as if your construction is off to a good start.  Here are my thoughts about your questions:

First, a basic question regarding true star wiring versus a common bus, in addition to your Legacy Cab/Base 2 control system, do you also want to use MTH's DCS command control system? If so, it's generally recommended to go with a complete hot and common star wiring scheme.  If only using Conventional, TMCC/Legacy, and or LionChief, a common buss would be fine.

Regarding TVS diode placement, I would suggest reading this Post: https://ogrforum.ogaugerr.com/...-about-tvs-placement

@Great Lakes RR posted:

- Recommendations for power source for the accessories?:  I have 2 PH 180's for the first two power districts. I have an old 80 watt lionel transformer from the 80's as well as a ZW of which only 1 of the two sides is operable.   I intend to have a small city/village with lighted interiors and street lights etc on the layout, etc.     I have a TPC 400 that I intended to use to support conventional operation on the track. Is it possible to use the TPC to divert some power at a constant voltage to the accessories (from one of the PH 180s)?

Yes, the 18VAC output from a PH180 can be split to supply multiple devices including a TPC 400.  The TPC 400 can in turn be adjusted so that it's output is reduced to a lower voltage suitable for accessories.  For example, somewhere between 10 to 14 volts AC, maybe less for lights if desired.

@Great Lakes RR posted:

- Block power management: From the posts and reviews, it appears that BPC2's functionality is mainly to simulate a toggle switch capability within the Cab2 remote.  If that were the case, I am leaning toward just setting up a panel with the labled toggle switches as that may be easier for me to follow than quickly getting to the right blocks/codes etch while operating trains.  Am I missing anything in terms of its functionality / will I regret forgoing the BPC2s for the power district?

You could initially use toggle switches for block control.  If specific LCS functionality, like automating routes for conventional locomotive control or automating accessories is desired after the layout is essentially completed, one or more BPC2s could be added (substituted, or either placed in series or parallel with the toggles) on a case by case basis.  The BPC2 manual may give you some more ideas of it's capabilities:

Link to Owner's Manual: BPC2 Owners Manual

I hope this helps.

Thank you Steve for your informative reply.   While I dont have any engines for DCC at the moment, I would like to preserve the opportunity.  If the "star" wiring scheme has the added benefit of better power distribution and/or less interference with a signal, then I'd be all the more inclined to go with that scheme.       

What is less clear to me is whether the common/ground can be connected via a 'bus' if the hot/powered wires are distributed on the 'star' approach.

Thank you for the other suggestions and links as well. 

Scot

I'm unsure about wiring for DCC, except that it has been noted here on the forum that the 455KHz TMCC/Legacy signal on the tracks is incompatible with DCC if trying to use both simultaneously.  Some MTH locomotives can use DCC or DCS.  Maybe you meant to say DCS, which can be used concurrently with TMCC/Legacy.

If wiring for DCS, Barry Broskowitz's book The DCS Companion is the definitive guide on this subject.

Although I have not read this book, other electronically knowledgeable members here on the forum who have done so and have larger layouts recommend running hot and common together following a Star wiring scheme for both conductors, wherein each wire in a pair have equal lengths.  I have also seen some who have twisted their wire pairs together, presumably to reduce signal interference/transmission.

Hopefully someone who is more knowledgeable about DCS Star wiring will chime in...