I am working with the Atlas HO-15 "Minimum - size twice around" track plan. I have it up and running. The wiring described in the plan book #11 was helpful. Now look at this option : I came off the bottom or top spur and continued to make an up and over ovel that comes back into the inside spur. The main layout is run be DC power, (1) transformer (for track power and switches). There is another transformer for the lights. All the plastic insulators are placed correctly on the main plan. Now with the extension of the up and over ovel I added, I am having problems with the placement of the new plastic insulators and running off the main transformer. I does not work. Do I need a separate transformer for this ovel? Where to place the insulators? Any help is needed. I am not running DCC.