My layout has grown like topsy - as a result I have 4 power packs in use; guess it could be called a 2 cab (or more) system. Question - can I use another power pack simply to power the approach track, turntable and roundhouse by simply starting the power on the approach track. Reading the Atlas Wiring Book it appears that I could use an Atlas 210 Twin switch and a series of Atlas 205 Connector switches for power to the turntable and roundhouse??? Will this work? Thanks for your help. ??? ??? ???
Generall what's done is to isolate a section of the approch track (longer than your longest locomotive) and wire it to your turntable power source and layout power source using a dpdt switch. This allows you to get the locomotive to the approach and then you can switch to local power.
This is similar to what you have to do for a wye. If your engine terminal has a number of tracks, you can isolate the whole terminal if you like. The Atlas instruction sheet for the turntable control shows how most of this can be done with that item.