MTH AIU remote Tortoise wiring

Norm,

I have not chimed in on this forum in quite some time, but could not resist your call for help.  I build layouts and custom control panels in the Chicagoland area.  The MTH AIU has two different types of programmed output relays.  There are ten that have momentary contacts and ten that have maintained contacts.  They are generally used for operating switches and operating accessories on the layout.  For your purpose, you will be using the maintained contacts or the ones used for accessories.  If you refer to the wiring diagrams that come with a Circuitron Tortoise machine, you will only be looking at figure #2 or #3.  If you want to use DC power to control the Tortoise, you would use two power supplies.  If you use AC power to control the Tortoise, you would need only one power supply but use steering diodes.  The SPDT switches shown in these two diagrams would actually be your connections to the AIU ACC terminals.

I hope this makes sense to you.  If not, let me know and I will draw you diagram.

Jim

Norm, I'm guessing what you are trying to achieve is similar to what I have done using Lionel's accessory switch controller.  It has the same characteristics that Jim stated about the AUI.  I set it for constant voltage and use AC for power.  I have two diodes as Jim noted.  Lionel has a video on their webpage which shows how to set this up using the ASC, but I would assume it would be the same using the AUI.

Hope you get this to work, I really like this way of controlling the switches.

You can also use 2 Double Pole Double Throw relays wired for latching operation in line from the AIU switch outputs. Wire it so each relay breaks the latch on the other when selected using the second set of contacts.

If you need a wiring diagram check DaleH's website. Lots of good info there.

I have drawn a diagram of the basic wiring for what I am trying to do (see diagram). What am I missing for this system?

Try hooking the white wire to the black wire and take it off the insulated rail .

Guy