I have a three rail layout in O-scale. My outer loop on my new layout is isolated, and i have the option of running either TMCC or conventional. What i want is a switch of some type that i can install that i can flip it to which i want at a time. So if i want to run conventional, i flip it to conventional. Since i have a inner loop that will be pure TMCC, i will need a switch to allow me to chose what i want to do on the outer loop.
Thanks Bill
Long time no see Bill.
I would think a simple SPDT would be the place to start. This will select between power sources, throttle for conventional, and full for command. There is a catch in all this, and that is that conventional engines need to be parked and isolated when you switch modes.
It would get pretty hairy, if you were trying to do this with a lot of blocks. Of course command locomotives can be set to run conventional, but that involves throwing the switch on the engine itself.
Hope this helps.
Hey bigboy, yea ive been busy. I totally took my old layout down to create a new, hopefully better layout. LOL I just have finished my first loop of track and am running conventional right now. I was planning on removing the conventional engine when i wasnt using it, i just have seen lots of nice engines i would like to have that i dont need TMCC for.
Thanks for the reply.
Bill
Yeah, depending on what you want to do, it can be a little awkward trying to mix control systems. I did a train show display last April where I had a loop of conventional that used relay automation, then a completely separate loop where I did a switching demo using command. Each system has advantages.
In your case where there is a connection between loops, an SPDT for each would give you full flexibility. You do understand how to wire that, don’t you?
Good luck on the new layout, building is half the fun.[swg]
a dpdt switch with a center off position is probably what you need. center terminals go to the track, the other pairs go to your control sources, one pair to each.
Actually, he only needs the one pole for the center rail on this project. The outside ground rails can all be wired in common and left unswitched. 3 rail command control is a little different from 2 rail.
So what y ou are saying is that i could wire all the outside rails together. But the inside ones would have a hot to one end of the switch, a hot to the otehr end of the switch, and the center contact would go to the track? if that is right then it appears to be fairly straight forward and easy.
Bill
Yup Bill. Are you using one large transformer for your track or are you phasing two smaller ones?
The TMCC signal can go everywhere, even onto the conventional section, it won’t hurt anything. This is really standard 2 throttle block wiring. An SPDT had 3 terminals on the back. The center goes to the track, the other 2, one to each source.
Say you have a ZW, put the conventional on one of the outside handles, A or D, because they are convenient to use. Then put the TMCC on B or C, because you don’t need to mess with it. Just set it to full, or slightly lower. You only need about 18V, even 15V might work, you can play with it. I’m debating whether to turn mine down a notch.
Did you know that you could use a regular 3-way light switch for this? They are just a form of SPDT. Fairly inexpensive too, but bulky.
Are you using DCS? I’m not sure the requirements, but I think this system is still OK.