Bypassing TIU for track power

Yes.  It's called "passive mode" and was discussed in this thread: https://ogrforum.com/...tive-or-passive-mode

The TIU channels can handle 10 amps apparently.  Are you expecting to exceed that?

Two other things to consider: if running conventional locos as well, your Protosound 2/3 ones will be limited by the voltage you supply to the track.  Might not be an issue with Pullmors, but it will definitely be an issue with something like an MPC with just a single hobby motor.  Those will race around the layout at voltages too low to even fire up a PS2 or PS3 engine.   The TIU has variable channels which allow you to send the track a variable voltage with the power supply at a constant 18V.  If you're running TMCC/Legacy, there's a cord that allows you to connect the command base to the TIU and run both MTH and Lionel command-equipped items with the DCS handheld.  You can still use the TMCC/Legacy remote for those items only.

The recent  TIU has 20 amp fuses for protection. Why not just use 10 amp protection ahead of it?

It's actually easier to protect the TIU using Passive mode. You can place Transient Voltage Suppressors on the track side of the TIU which prevents the spikes from backtracking into the TIU. It also allows for bigger power supplies. The only down side is that the E-stop function doesn't work on the TIU (we have panel-mounted buttons on the layout that shut down the whole layout).

@AGHRMatt how do you enable passive mode and what do you mean by transient voltage suppressors and where can I get them? And if I do it that way do I hook the TIU up the regular way? As in transformers to the inputs and output to the voltage suppressors and then to track?

Our new layout at the club is using DCS in passive mode for the exact same reason, while the TIU is designed to handle the current, logic says if it doesn’t have to it’ll work longer. It was found a few year back that a 22uh choke helps keep the power clean and ready to accept the DCS signal. Check THIS thread.

for this I came up with this PCB to hold the choke plus a TVS diode.

for information on the TVS diode put simply just search TVS diode of the forum and you’ll get more information that you’ll ever want to know.

I actually have a new run of these PCB’s for passive mode operations if interested contact me via my profile email address

@zhubl email sent, I appreciate it!