• Combined AC/DC circuits?

  • Discussion related to everything about model railroading, from layout design and planning, to reviews of related model tools and equipment. Discussion includes O, S, HO, N and Z, as well as narrow gauge topics. Also includes discussion of traditional "toy train" and "collector" topics such as Lionel, American Flyer, Marx, and others. Also includes discussion of outdoor garden railways and live steamers.
Discussion related to everything about model railroading, from layout design and planning, to reviews of related model tools and equipment. Discussion includes O, S, HO, N and Z, as well as narrow gauge topics. Also includes discussion of traditional "toy train" and "collector" topics such as Lionel, American Flyer, Marx, and others. Also includes discussion of outdoor garden railways and live steamers.

Moderators: 3rdrail, stilson4283, Otto Vondrak

  by chrisnewhaven
 
OK, I’m installing a new signal system on my layout. In order to operate it, normal AC current runs through the middle rail of the Lionel Fastrack I use and the outer rails are the ground. In addition to that, I insulated the two outer rails from each other on two track sections, and hooked up the DC ground from my signal to one of the outer rails. The ground from the DC transformer is hooked up to the other outer rail. When a train passes over the two insulated sections, the wheels complete the DC circuit triggering a relay to change the signal from green to red. The DC circuit does not affect the train because it is only in the outer rails (the ground of the AC circuit) and not the middle rail.
My question is will having the ground of my DC circuit using the same wires as the ground of the AC circuit affect any electronics in a locomotive or the transformer (a Lionel type R)? Before I proceed with anything else I want to make sure it is safe for the long term (I have already operated it for a few minutes to test the system).
C.J.V.