Anyone have any luck with running a MTH TIU in Passive mode just feeding the outputs to 3 or 4 isolated rail lines already fed by Lionel TMCC? I also need to be able to run in conventional mode sometimes, this is why I like the TMCC as primary power supply and not running through the TIU with track power. I have not found many postings on this configuration. Any other options are welcome. What I have set up now is not working. The TIU is powered with a separate transformer.
Thanks - Frank
Replies sorted oldest to newest
What's not working about it? Connecting the transformer to the track.
I run the power through the TIU and connect the Legacy to the outside rail. I can run conventional on the variable TIU outputs using the DCS remote and Legacy as well.
I have 3 levels on the layout and was trying to continue using conventional on all 3. The TIU is variable only on 2 out of 4 outputs. I would only be able to use conventional on 2 levels or do I run all 3 transformers controlled by TMCC through the TIU? This would give me variable power through the TIU fixed voltage outputs. I would just need to use the TMCC CAB 1 for conventional operations if I understand correctly.
The TIU is variable only on 2 out of 4 outputs.
If you operate in passive TIU mode, you will not have use of either variable channel except by putting them into fixed mode. Passive mode disallows use of variable channels.
However, if you operate the TIU as it is intended to be operated right out of the boxl, you can certainly operate DCS, TMCC/Legacy and conventional engines all together, even at the same time on the same track.
This and a whole lot more is all in MTH’s “The DCS O Gauge Companion 2nd Edition", available for purchase as an eBook or a printed book at MTH's web store!
For what should be obvious reasons! 
Thank you for the information, I will rewire everything tomorrow and see if my MTH engine has better luck with the signal. Nothing like a run away train to get you moving! 
I am redoing the wiring now and have a question about the common ground. With a larger layout that has the grounds from 3 transformers connecting to a buss do I connect both sides of the TIU to the buss also? Sorry about the quality of the diagram. I will clean it up later.
Access to this requires an OGR Forum Supporting Membership
